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    The Complete Genome Sequence of the Gram-Positive Bacterium Bacillus subtils Bs-916
    WANG Xiao-Yu, LUO Chu-Ping, CHEN Zhi-Yi, LIU Yong-Feng, LIU You-Zhou, NIE Ya-Feng, YU Jun-Jie, YIN Xiao-Le
    Scientia Agricultura Sinica    2011, 44 (23): 4807-4814.   DOI: 10.3864/j.issn.0578-1752.2011.23.006
    Abstract850)      PDF (546KB)(1648)       Save
    【Objective】The objective of this study is to sequence the whole genome of Bacillus subtils Bs-916 and provide more information about molecular biology for future mining and utilizing the potential of this strain. 【Method】 Application of comparative genomics softwares, the whole genome sequence analysis was carried out with Bs168 strains. 【Result】 Bs-916 strains genome is 3 925 958 base pairs comprises 4 056 protein-coding genes. The average GC ratio is 46.4%, the highest compared with other whole-genome sequencing of Bacillus spp.. It contains 152 tandem repeat region, 103 transposons, 37 IS (Insert sequence), 46 tRNA, 39 rRNA. Through comparative genomics analysis, Bs-916 harbors eight giant gene clusters directing synthesis of bioactive peptides and polyketides by modularly organized mega-enzymes named non-ribosomal peptide synthetases, NRPS and polyketide synthases, PKS. Macrolactin, difficidin, and bacillomycin L are absent in Bs168 strains. Bs-916 also contains phytase gene, comAPQX and sfp related with biocontrol mechanism.【Conclusion】Bs-916 strain genome contains many gene cluster encoding a variety of antimicrobial substances, it can be considered a paradigm for an own group of plant-associated gram-positive bacteria with a huge potential for biocontrol and plant growth promotion. The complete genome sequence along with its amenability to genetic manipulation, should facilitate exploitation of the hitherto unappreciated potential of strain Bs-916 to produce secondary metabolites for developing agrobiological engineering preparations.
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    Cited: Baidu(4225)
    Study on Precise and Quantitative N Application in Rice
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    Scientia Agricultura Sinica    2005, 38 (12): 2457-2467.   DOI: 10.3864/j.issn.0578-1752.as-2003-2033
    Abstract1613)      PDF (490KB)(1391)       Save
    This study is based on the Stanford equation and aims at getting high yield and high quality rice. With the aid of stage and monomial method of quantitative determination, the three parameters of the precise and quantitative N application theory and technology were measured and validated. In the process of study new, methods and route were found preliminarily, such as a new method for determination of the amount of N requirement by grading the yield of a field, a new route to study by demarcating the N supplied by organic fertilizer to the N supply ability of a field and the great effect of the ratio of N applied as basal fertilizer and that as panicle fertilizer on the NUE was proposed. The research has solved the technology of precise and quantitative N application of total amount of N and its splitting application, thus enabling the application of this technology and supporting the application of "3S" technology.
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    Cited: Baidu(220)
    Impact of Land Fragmentation on Small Rice Farmers’ Technical Efficiency in Southeast China
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    Scientia Agricultura Sinica    2006, 39 (12): 2467-2473.   DOI: 10.3864/j.issn.0578-1752.at-2005-6363
    Abstract1511)      PDF (306KB)(1067)       Save
    Rice farming is important for income generation and poverty reduction in large parts of China. The high degree of land fragmentation, however, may constitute a major bottleneck to increasing productivity and reducing poverty. This paper applies detailed household, crop and plot level data to investigate the impact of land fragmentation on rice producers’ technical efficiency in a major rice growing area of Southeast China, using a stochastic frontier model. Average technical efficiency scores are 0.85 for early rice, 0.83 for late rice, and 0.79 for one-season rice production in our research area. This indicates that with the existing technologies, a considerable productivity improvement can still be reached by addressing the factors constraining technical efficiency increases. Land consolidation can be an important option in this respect, as average plots size is found to have a significant positive impact on technical efficiency for all three types of rice.
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    Cited: Baidu(204)
    Changes of Aroma Constituents in Apricot During Fruit Development
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    Scientia Agricultura Sinica    2005, 38 (06): 1244-1249.   DOI: 10.3864/j.issn.0578-1752.at-2004-2829
    Abstract999)      PDF (363KB)(1036)       Save
    The aroma constituents present in apricot fruit during three different developmental stages were studied. The three stages include mature green stage, commercial ripe, and tree ripe stage. The fruits were sampled by simultaneous distillation-extraction. The concentrated extracts were analyzed by capillary gas chromatography-mass spectrometry. The aromatic constituents behaved differently during the fruit developmental period. Alcohols, aldehydes, ketones, lactones, esters and acids were the major constituents in the sample extracts. A total of 35 compounds were identified in the mature green stage, including (E)-2-hexenal, linalool, α-terpineol, (E)-2-hexen-1-ol, hexanal, 1-hexanol. Forty-five compounds at commercial ripe stage were detected, among them the important compounds were (E)-2-hexenal, linalool, α-terpineol, hexanal, ocimenol and geraniol. Meanwhile, 44 were found at tree ripe stage, and the main components were linalool, (Z, Z, Z)-methyl 9, 12, 15-octadecatrienoate, α-terpineol, γ-decalactone, γ-dodecalactone, butyl acetate, hexyl acetate. The maximum of C6 aldehydes and alcohols were found at mature green stage, diminishing in concentration as ripening proceeded. Several terpenic alcohols were found at different stages of ripening. Their maximum concentrations were found at commercial ripe stage. To the contrary, the presence of lactones and ketones was not detectable until the commercial ripe stage. Some esters were also found such as butyl acetate, 3-hexenyl acetate, hexyl acetate, 2-hexenyl acetate, etc. Except 2-hexenyl butanoate and 2-hexenyl hexanoate , the levels of others increased during fruit maturation.
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    Cited: Baidu(166)
    The Effects of NaCl Stress on Plant Growth, Chlorophyll Fluorescence Characteristics and Active Oxygen Metabolism in Seedlings of Two Cucumber Cultivars
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    Scientia Agricultura Sinica    2004, 37 (11): 1754-1759.   DOI: 10.3864/j.issn.0578-1752.041131
    Abstract934)      PDF (103KB)(1080)       Save
    Two cucumber (Cucumis sativus L.)cultivars,'Jinyan 4' (salt tolerant) and 'Jinlü4' (salt sensitive) were grown in nutrient solutions with three NaCl levels(0,25,50 mmol·L-1)for the investigation of plant growth, chlorophyll fluorescence and active oxygen metabolism in seedling leaves. The results showed that NaCl stress decreased plant growth, chlorophyll content, quantum yield of PSII (ΦPSII),initial fluorescence yield(Fo)and non-photochemical quenching of fluorescence(NPQ). The plant growth of 'Jinyan 4' was less affected by salt stress than 'Jinlü4' and the photosynthetic apparatus was less injured by salt stress than 'Jinlü4'. However, photochemical efficiency of PSII (Fv/Fm) was not affected by salt stress. Meanwhile,salt stress significantly increased the activity of ascorbate peroxidase (AsA-POD) and significantly decreased superoxide dismutase (SOD) activity in 'Jinlü4'. Free radical producing rate, and H2O2 and MDA content increased with increasing NaCl levels, however, less H2O2 content and lipid peroxidation were observed in the leaves of 'Jinyan 4' than 'Jinlü4'. It is concluded that higher SOD activity, less H2O2 and MDA content may be involved in higher salt tolerance of 'Jinyan 4'.
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    Cited: Baidu(164)
    Analysis of Genetic Diversity and Genetic Basis of Chinese Rapeseed Cultivars (Brassica napus L.) by Sequence-Related Amplified Polymorphism Markers
    YanCheng Wen,,,,
    Scientia Agricultura Sinica    2006, 39 (02): 246-256.   DOI: 10.3864/j.issn.0578-1752.at-2005-5414
    Abstract1841)      PDF (578KB)(2577)       Save
    【Objective】In order to investigate the Genetic diversity and genetic basis of rapeseed (B. napus L.) in China, 【Method】Total 130 accessions developed in different years since 1949 were analyzed using SRAP (sequence-related amplified polymorphism) markers. 【Result】A total of 509 amplified fragments and 123 polymorphic fragments were detected by applying 25 SRAP primer combinations. The polymorphic fragment percentage was 24%. The number of amplified fragments and polymorphic fragments per primer combination were 20.4 and 4.9, respectively. 130 B. napus accessions were divided into four groups of A, B, C and D at genetic distance of 0.12. About 78.5% of total accessions were classified into group C. Group C could also be divided into I, II, III, IV and V sub-groups at genetic distance of 0.10. About 58.5% of total accessions were classified into sub-group I, indicating the genetic diversity of 58.5% accessions of total was poor. The results demonstrated that the genetic basis of B. napus L. accessions released before 1980 was the narrowest while those released in 1980s reached the widest. In 1990s, the genetic distances of B. napus L. accessions declined again. The genetic basis of B. napus L. accessions narrowed further after 2000. Though the difference of mean genetic distance between accessions bred in 1990s and after 2000 did not reach a significant level, the difference in mean genetic distance in different periods was at 0.01 or 0.05 significant level. The difference in mean genetic distance between accessions bred in China and introduced from abroad reached a significant level at 0.01. 【Conclusion】All these results showed that SRAP markers were economic, effective, and reliable.
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    Cited: Baidu(160)
    A Study on Characteristics of Photosynthesis in Super High-yielding Hybrid Rice
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    Scientia Agricultura Sinica    2005, 38 (02): 258-264.   DOI: 10.3864/j.issn.0578-1752.at-2004-2185
    Abstract927)      PDF (383KB)(1152)       Save
    The morphological features and photosynthetic characteristics of 7 hybrid rice combinations with different canopy structure and super high-yielding potential were studied in comparison with Shanyou 63.The results showed that 4 combinations having significant increase in grain weight per plant compared with Shanyou 63 have advantages including (1) a smaller light extinction coefficient resulted from the more erect leaf blades and longer flag leaves enhanced the capacity of source supply on the basis of significant increase of sink demand (i.e. spikelets per panicle), (2) a higher rate of canopy photosynthesis during grain filling and higher rates of flag leaf photosynthesis at saturating light intensity during different stages (i.e. booting stage,10 days after heading, 30days after heading), (3) More dry matter accumulated in stems and sheaths before heading and translated to grains after flowering efficiently.
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    Cited: Baidu(149)
    Allelic Variation at the Glu-1 and Glu-3 Loci and Presence of 1B/1R Translocation, and their Effects on Processing Quality in Cultivars and Advanced Lines from Autumn-Sown Wheat Regions in China
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    Scientia Agricultura Sinica    2005, 38 (10): 1944-1950.   DOI: 10.3864/j.issn.0578-1752.at-2004-2827
    Abstract1044)      PDF (221KB)(1088)       Save
    Storage protein composition played an important role in determinating the processing quality in common wheat. Totally, 251 Chinese wheat cultivars and advanced lines from autumn-sown wheat regions in China were used to investigate the high molecular weight glutenin subunits (HMW-GS) and low molecular weight glutenin subunits (LMW-GS) composition controlled by the Glu-1 and Glu-3 loci, as well as the presence of 1B/1R translocation, and to determine the association of storage protein composition with protein content, SDS sedimentation value, and dough properties. HMW-GS of Null, 7+9, 2+12, and LMW-GS of Glu-A3a and Glu-B3j associated with poor quality were the dominant glutenin subunits, and their frequencies were 39.4%, 45.0%, 59.8%, 37.1% and 44.6%, respectively. Less significant effect of glutenin subunits and glutenin subunit interaction was observed on protein content. According to the glutenin subunit contribution to SDS sedimentation value, mixing time and mixing tolerance, different glutenin subunit loci could be ranked as: Glu-D1>Glu-B3>Glu-B1>Glu-A3>Glu-A1. At Glu-A1, 1>2*>N; at Glu-B1, 7+8> 14+15>7+9; at Glu-D1, 5+10>4+12>2+12; at Glu-A3,Glu-A3d>Glu-A3a>Glu-A3c>Glu-A3e; at Glu-B3, Glu-B3d>Glu-B3b> Glu-B3f>Glu-B3j. Lines carrying 1B/1R translocation showed significantly deleterious effect on gluten quality such as SDS sedimentation, mixing time and mixing tolerance.
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    Cited: Baidu(149)
    Effect of Real-time and Site-specific Nitrogen Management on Various Hybrid Rice
    Fan He Kehui Cui Qiang Wang
    Scientia Agricultura Sinica    2008, 41 (2): 470-479.   DOI: 10.3864/j.issn.0578-1752.2008.02.021
    Abstract1543)      PDF (432KB)(1035)       Save
    Site-specific N management (SSNM) and real-time N management (RTNM) improves fertilizer-N use efficiency of irrigated rice. This study was conducted to compare the most popular hybrid varieties, three-line hybrid rice-Shanyou63 (SY63) and two-line hybrid rice-Liangyoupei9 (LYP9), in their response to N application and fertilizer-N use efficiency under RTNM and SSNM in field conditions in 2004 and 2005. 【Method】The two varieties were grown under eight and six N treatments in 2004 and 2005, respectively, in Hubei, China. N treatments included a zero-N control, a SSNM and several RTNM with different chlorophyll meter (SPAD) thresholds. 【Result】The results showed that, color of rice leaves had genotypic difference between varieties, the SPAD reading of SY63 had 1.7-2.0 units lower than that of LYP9 while both varieties were under zero or the same fertilizer-N rates. The fertilizer-N rate showed significant exponential correlation with the SPAD threshold based on RTNM for both varieties. The equations for SY63 and LYP9 were, N rate=0.9956 e0.132 SPAD (r2=0.8338**), and N rate=0.1565 e0.173 SPAD (r2=0.9508**), respectively. It was found that, additional fertilizer-N 37.3 kgN.hm-2 was required for SY63 to maintain the same SPAD value in comparison with that of LYP9, when SPAD thresholds were among 36-40 under RTNM. 【Conclusion】When average fertilizer-N rate was around 160 kgN.hm-2, LYP9 showed similar capacity and characteristics on N uptake, N recovery use efficiency, and nitrogen use efficiency based on grain production, in comparison with that of SY63. But LYP9 had greater nitrogen use efficiency based on biomass production, fertilizer-N agronomic use efficiency, in comparison that of SY63 respectively. However, SY63 had greater nitrogen harvest index than that of LYP9. The results also showed that, LYP9 had greater tolerance against lodging than that of SY63 when excessive fertilizer-N applied.
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    Cited: Baidu(136)
    Modeling the Effect of Rainfall and Irrigation on Nitrate Leaching and Crop Yield in Wheat-Maize Cropping System in North China Plain
    LI Gui-Hua, ZHANG Yan-Ping, HU Ke-Lin
    Scientia Agricultura Sinica    2013, 46 (3): 545-554.   DOI: 10.3864/j.issn.0578-1752.2013.03.011
    Abstract643)      PDF (693KB)(1024)       Save
    【Objective】The objectives of the study are to quantify nitrate leaching and crop yield under different rainfall-year and irrigation methods and to provide information for improving farmer’ s practice under different types of rainfall-year. 【Method】Rainfall and irrigation is very important for water and nitrogen movement and crop yield in North China Plain. Therefore, 40-year (1966-2005) real climate data combined with the validated water and nitrogen management model were used to predict nitate leaching and crop yield under five irrigation methods, i.e. three times of irrigation (during winter, stem elongation and grain filling) in winter wheat season with amount of (A) no irrigation, (B) (50+50+50) mm, (C) (70+70+70) mm, (D) (90+90+90) mm,(E) (120+120+90) mm, and two times (seedling and milk-ripe stage) for summer maize with amount of (A′) no irrigation, (B′) (80+0) mm, (C′) (80+70) mm, (D′) (90+80) mm, (E′) (100+100) mm. 【Result】The simulated results showed that the grain yield increased with the enhancement of irrigation or rainfall during wheat season. About 87.2% of rainfall in all years was less than 200 mm, and the amount of nitrate leaching with irrigation method (D) was in the range of 0-30.9 kg N•hm-2. When rainfall was over 200 mm (12.8% of all years), irrigation method (C) was better as the level of nitrate leaching was low (0.06-41.2 kg N•hm-2) and crop yield was high. During summer maize season, crop yield also increased with the increase of rainfall until 600 mm. The irrigation methods (D’, C’ and B’) could be used based on the range of rainfall <250 mm (probability 17.9%), 250-450 mm (64.2% of all years) and >450 mm (17.9% of all years), respectively. The amount of nitrate leaching was in the range of 0-7.3 kg N•hm-2, 0-82.2 kg N•hm-2 (probability of N leaching belongs to grade I was 84.2%, and grade III was only 5.3%) and 0-61.6 kg N•hm-2 (probability of N leaching belongs to grade I was 86.8%, and grade III was only 2.6%), respectively. 【Conclusion】 Stochastic rainfall and its distribution in different seasons must be taken into farmer’s irrigation practices for keeping crop yields and mitigating N leaching in North China Plain. In normal-rainfall year, (D) and (C’) irrigation methods should be recommended in wheat and maize season, respectively.
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    Cited: Baidu(134)
    Studies on the Rice RVA Profile Characteristics and Its Correlation with the Quality
    Scientia Agricultura Sinica    2005, 38 (04): 657-663.   DOI: 10.3864/j.issn.0578-1752.at-2004-2441
    Abstract1154)      PDF (231KB)(1777)       Save
    Rice quality is a key factor and widely concerned by rice breeders and consumers, but it is difficult to evaluate it only through physical and chemical indices. In this study, 114 and 105 varieties including indica, japonica and waxy varieties were employed in two replicates to study the relationship between RVA profile characteristics and rice quality, including the appearance quality, cooking physico-chemical factor and cooking quality. The main results were as follows: (1) RVA profiles characteristics had close relationships with translucency and chalkiness. Rice varieties with higher chalkiness had significant AAC, HPV, CPV, SBV and CSV. (2) RVA profiles characteristics had significant correlation with AAC and GC, but no significant with GT. (3) With the exception to PKV, all the other RVA profiles characteristics correlated significantly with eating quality. These results showed that RVA profiles characteristics could be used as indices to assist in varietal selection for good cooking rice quality.
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    Cited: Baidu(128)
    Review of History and the Recent Development of Organic Farming in the World
    Scientia Agricultura Sinica    2004, 37 (10): 1510-1516.   DOI: 10.3864/j.issn.0578-1752.041018
    Abstract1288)      PDF (732KB)(1437)       Save
    The history of organic farming in the world is reviewed in this paper. The development of organic farming in the world had gone through three stages, e.g. emergence, expansion and growth. The contributors and their thoughts during the different development stages of organic farming were briefly introduced. The development status of organic farming in the world is reviewed by land area under organic management, land area under organic management in percent of total agricultural area and world markets for organic products. The main existing problems for the further development of the organic farming in the world are discussed. The development status, problems and strategies of organic farming in China are briefly introduced.
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    Cited: Baidu(121)
    Microsatellite Analysis of Genetic Diversity and Phylogenetic Relationship of Eight Donkey Breeds in China
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    Scientia Agricultura Sinica    2006, 39 (02): 398-406.   DOI: 10.3864/j.issn.0578-1752.at-2005-5537
    Abstract2403)      PDF (374KB)(1923)       Save
    【Objective】To reveal the genetic diversity and phylogenetic relationship of china donkey breeds, 【Method】 the genetic polymorphisms of 24 microsatellites in 8 china large and middle-sized donkeys were studied by means of PCR polyacrylamide gel electrophoresis and silver staining. Number of alleles, average effective number of alleles (E) and average rates of homozygote of each breeds were counted. According to allele frequencies of 24 microsatellites, polymorphism information content(PIC),mean heterozygosity (h) and genetic distances (DA) were calculated for each breeds, By using the Neighbour-joinig method of Dispan software, the polymorphic trees were constructed based on genetic distances. The systematic relation was analyzed as well. 【Result】The results showed that NVHEQ18 is medium polymorphic and the other 23 of 24 microsatellite loci were highly polymorphic, The average PIC (0.6940), h (0.7119) and E (2.9) of the eight donkey breed population were all higher ,which showed the gene polymorphisms and genetic diversity were higher. Guanzhong donkey、Jinnan donkey、Guangling donkey and Dezhou donkey of large breeds and Qingyang donkey of middle-sized clustered in one group and Biyang donkey、Huaiyang donkey and Jiami donkey of middle-sized clustered in another groups. The phylogenetic relationship between different breeds were in accordance with their breeding history and distribution. 【Conclusion】The 24 microsatellite loci were effective markers for analysis of genetic relationship among donkey breeds.
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    Cited: Baidu(114)
    Influence of Silicon on Cadmium Availability and Cadmium Uptake by Maize in Cadmium-contaminated Soil
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    Scientia Agricultura Sinica    2005, 38 (01): 116-121.   DOI: 10.3864/j.issn.0578-1752.at-2004-2197
    Abstract1024)      PDF (354KB)(958)       Save
    Pot experiments were conducted to investigate the influence of silicon on soil cadmium fractionation and cadmium uptake by maize (Zea may L. Nongda 108). The results showed that Cd toxicity in maize treated with Cd at 0.1 or 1.0 mmol·kg-1 (added as CdSO4·8/3H2O) was significantly alleviated by addition of 2.0 g·kg-1 sodium metasilicate (NaSiO3·9H2O) due to the decreased Cd uptake by maize. The ameliorative effect of Si was due to lower exchangeable Cd and Fe/Mn oxide-bound Cd, and higher carbonate-bound and residual Cd in Si-treated Cd-contaminated soils compared with non-Si-treated ones. One of the possible mechanisms of Si-enhancement of resistance to Cd toxicity is that silicate alters the Cd forms in soil, resulting in reduction of Cd bio-availability.
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    Cited: Baidu(112)
    Dynamics of Ecological Footprint and Ecological Capacity of Shaanxi
    Scientia Agricultura Sinica    2005, 38 (04): 746-753.   DOI: 10.3864/j.issn.0578-1752.at-2004-2928
    Abstract1228)      PDF (460KB)(1048)       Save
    The ecological footprint and ecological capacity of Shaanxi Province during 1978 to 2002 was studied, and the forecast model was obtained which shows how the two vary with the time, and the tend of future sustainable development of Shaanxi was forecasted. The results showed that the average personal ecological footprint gradually increased from 0.5508 ha to 1.1059 ha during 1978 to 2002 , whereas, the average personal ecological capacity declined year by year from 0.917 ha to 0.8102 ha. A conclusion could be drawn that the ecological footprint and ecological capacity development just in the opposite direction. In 1978 the ecological surplus was 0.4009 ha, and in 1992 ecological deficit arose, which rose to 0.2958 ha by 2002. The forecast showed that the average ecological footprint would be 1.2013 ha in 2010 and 1.528 ha in 2015, and that the average personal ecological capacity would be 0.7638 ha in 2010 and 0.7198 ha in 2015, and that the average personal ecological deficit would reach to 0.4378 ha in 2010 and 0.5330 ha in 2015. The research indicates that the utilization of natural resource in Shaanxi is increasing year by year, which is beyond the capacity of the natural ecological system, the conflicts between ecological footprint and ecological capacity are going up, the present developing model is not sustainable, the ecological environment is at risk.
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    Cited: Baidu(111)
    Correlation Between Corn Leaf Spectral Reflectance and Leaf Total Nitrogen and Chlorophyll Content Under Different Nitrogen Level
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    Scientia Agricultura Sinica    2005, 38 (11): 2268-2276.   DOI: 10.3864/j.issn.0578-1752.at-2005-5374
    Abstract1426)      PDF (232KB)(1091)       Save
    The correlation between the corn leaf chlorophyll content, total nitrogen content, moisture content and leaf spectral reflectance was studied in a patted experiment under different N treatments. Results showed that shooting stage and trumpet stage were sensitive stages for diagnosis of nitrogen in corn. The precision of inferring leaf nitrogen and chlorophyll concentration by leaves maximal spectral reflectance at green waveband was: trumpet stage > shooting stage > anthesis-silking stage. Different wavebands should be chosed for diagnosis of corn leaf nitrogen and chlorophyll concentration in different development stages. It was proved that the reliability of using visible spectral reflectance was preferable than other wavebands at shooting stage and trumpet, but near infrared spectral reflectance was more reliable at anthesis-silking stage. The combination spectra variables of two wave bands were better than single wave band to estimate the content of leaf total nitrogen and chlorophyll.
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    Cited: Baidu(109)
    Cloning and Characterization of Drought-stress Responsive Gene GhGR in Gossypium hirsutum L.
    SONG Gui-Fang-., FAN Wei-Li, WANG Jun-Juan, WANG De-Long, WANG Shuai, ZHOU Kai, YE Wu-Wei
    Scientia Agricultura Sinica    2012, 45 (8): 1644-1652.   DOI: 10.3864/j.issn.0578-1752.2012.08.021
    Abstract790)      PDF (1036KB)(597)       Save
    【Objective】The objective of this study is to clone and make bioinformatics analysis of  the sequence of the glutathione reductase gene from G. hirsutum L.【Method】The full length of GhGR was cloned by RACE and RT-PCR techniques,the gene sequence obtained and the putative amino acid sequence were analyzed by bioinformatics software. Its expression patterns were analyzed by real-time PCR and instantaneous expression. 【Result】The GhGR full length cDNA sequence contained 1 035 bp, and ORF was 792 bp, which encoded 263 amino acid residues. Bioinformatics analysis showed that GhGR had high similarity of 90%, 91% and 91% to Populus trichocarpa (XP_002299276.1), Ricinus communis (XP_002518118.1) and Vitis vinifera (CAN74593.1), respectively. Phylogenetic analysis showed that GhGR was much closer to Vitis vinifera, the expression protein of GhGR was located in the cell membrane and cell nucleus membrane, and its expression could be induced by drought.【Conclusion】The glutathione reductase gene GhGR was cloned for the first time from G. hirsutum L. The further studies of GhGR will have an important significance in drought- tolerance for cotton breeding.
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    Cited: Baidu(106)
    Degradation of Antibiotics and Passivation of Heavy Metals During Thermophilic Composting Process
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    Scientia Agricultura Sinica    2006, 39 (02): 337-343.   DOI: 10.3864/j.issn.0578-1752.at-2004-2884
    Abstract3280)      PDF (423KB)(3378)       Save
    【Objective】The problem that there are various antibiotic medicines and heavy metal elements in excrements of livestock and poultry have been concerned on the farm utilization extensively. The techniques for the antibiotics degradation and heavy metals passivation were studied in the experiments.【Method】As composting is a new alternative bioremediation technology for treatment of organic pollutants and heavy metals, two experiments were conducted to evaluate the effect of using thermophilic composting to break down the content of tetracyclines(TTC, OTC, CTC) and H2O extractible of heavy metals(Cu, Zn, Cr, As). 【Results】The result of TCs degradation test indicated that the degradation of TTC, OTC and CTC using P+S and C+S in all treatments was effective, but in comparision, the addition of BM bacterium for TCs degradation in treatment was more effective, and its biodegradation rate was higher than that of P+S+TCs and C+S+TCs treatment. The biodegradation rate of OTC was the lowest in all treatments, and the rate of C+S+OTC treatment was 40.23%. The order of the three TCs biodegradation rate was TTC> CTC> OTC. The air-slaked coal has a passivation effect on the heavy metal elements in excrements of livestock and poultry. The result of heavy metal passivation test showed that the effect of addition of air-slaked coal to H2O extractible content of heavy metals, such as Cu, Zn, Cr and As, were obvious, the passivation effect of ari-slaked coal treatment was better than that of control. The H2O extractible content of heavy metals of Cu, Zn, Cr and As, after composting of pig manure, reduced by 6.17%, 6.40%, 4.17% and 1.83%, respectively, meanwhile, the H2O extractible contents after composting of chicken manure reduced by 7.07%, 5.69%, 5.50% and 2.07%, respectively. 【Conclusion】With the different thermophilic composting conditions, tetracyclines antibioticses can be degraded, and the addition of foreign beneficial bacterium can reduce residues in antibiotic medicine. Thermophilic composting also can lower the effects of heavy metals on plants. Air-slaked coal has passivation function on extractible heavy metals.
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    Cited: Baidu(106)
    Changes of Organic Carbon and Nutrient Contents in Highly Productive Paddy Soils in Yujiang County of Jiangxi Province
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    Scientia Agricultura Sinica    2006, 39 (02): 324-330.   DOI: 10.3864/j.issn.0578-1752.at-2005-5840
    Abstract2846)      PDF (381KB)(1805)       Save
    【Objective】Studies on changes in organic carbon and nutrient contents of the highly productive paddy soils would be scientifically beneficial to the directional management and sustainable utilization of paddy soils. 【Method】The contents of organic carbon and nutrients and their changes in the last over 20 years in the highly productive paddy soils as related to the environmental significance were investigated by field sampling and comparison with the corresponding values in the Second Soil Survey in Yujiang County of Jinagxi Province. 【Result】Results showed that 0-10 cm depth highly productive paddy soils in Yujiang County of Jiangxi Province contained organic carbon content of (20.2±3.88) g·kg-1, total N (2.09±0.55) g·kg-1, available phosphorus (42.7±32.7) mg·kg-1, respectively, all were at the very rich level. In the last over 20 years, the organic carbon pool of the highly productive paddy soils remained a stable state, total N and available P increased significantly, while available K changed little. The amount and percentage of P immobilized in 0-10 cm highly productive paddy soils were (142.7±41.1) mg·kg-1 and (36.2±10.4)% and of added P CEC was (7.93±1.32) cmol·kg-1, being not higher than the mean value of paddy soils and that in upland red soils. It indicated that fertilizer P in highly productive paddy soils would be a high mobility and easily moved to water, being a main source of nutrient causing eutrophication. 【Conclusion】For a long-term rice cultivation and fertilization, the highly productive paddy soils were very rich levels of organic matter and available P, and a steady state of organic carbon pool, while amount of P immobilized was not high. Because of a weak K-fixing capacity, the available K content was not rich in highly productive paddy soils, suggesting that attention should be paid to the balance and increase of soil K pool.
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    Cited: Baidu(105)
    Nitrous oxide emission from rice-duck complex ecosystem
    Scientia Agricultura Sinica    2008, (9): 2895-2901.   DOI: 10.3864/j.issn.0578-1752.2008.09.044
    Abstract1215)      PDF (384KB)(932)       Save
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    Cited: Baidu(103)
    Effects of Exogenous Calcium on Photosynthesis and Its Related Physiological Characteristics of Rice Seedlings Under Salt Stress
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    Scientia Agricultura Sinica    2004, 37 (10): 1497-1503.   DOI: 10.3864/j.issn.0578-1752.041016
    Abstract1383)      PDF (588KB)(1086)       Save
    Two rice (Oryza sativa L.) cultivars, Wuyujing No.3 (salt-tolerant) and IR36 (salt-sensitive), were used to investigate the effects of exogenous calcium on some photosynthetic and physiological characteristics of the leaves of rice grown under salt stress. The results showed that the photosynthesis and photosynthetic efficiency of the leaves of salt-stressed rice were significantly enhanced with the inclusion of Ca2+. The levels of net photosynthetic rate and stomatal conductance increased more significantly than the control without Ca2+, and the rate of increase or decrease of intercellular CO2 concentration and stomatal limitation value were faster than that of the control without Ca2+ too. Addition of Ca2+ increased the contents of chlorophyll, proline and soluble sugar of the leaves of rice under salt stress. Furthermore, addition of Ca2+ reduced the content of MDA and the permeability of cell membrane, but increased the SOD activity.
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    Cited: Baidu(102)
    The Causal Microorganisms of Panax notoginseng Root Rot Disease
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    Scientia Agricultura Sinica    2006, 39 (7): 1371-1378.   DOI: 10.3864/j.issn.0578-1752.at-2005-6614
    Abstract1175)      PDF (397KB)(1630)       Save
    【Objective】Panax notoginseng, cultivated in Yunnan, China, is an important medicinal herb. Rot root disease is the most serious problem limiting the production of the herb. 【Method】 Panax notoginseng root rot disease was surveyed and sampled in the field. The pathogens of the root rot was isolated and identificated. Pathogenecity tests in vitro and in field were carried out. 【Result】A survey on the disease indicated that the symptoms of the disease are expressed as dry chap rot, medullary tissue rot, slowly yellow rot, stem base dry rot, suddenly wilt rot and wet rot. Among them, slowly yellow rot and suddenly wilt wet rot were the most popular ones. Dry chap rot, medullary tissue rot and stem base dry rot are new records for symptoms of the disease. Cylindrocarpon destructans, C. didynum, Fusarium solani, Phytophthora cactorum, Phoma herbarum, Monilia sp., Verticillium sp., Trichoderma sp., Rhizoctonia solani were involved in the disease. In vitro pathogenecity tests demonstrated that C. destructans, C. didynum, P. cactorum, P. herbarum and R. solani could result in the disease at different levels. Field inoculation tests showed that P. cactorum and P. herbarum were the most pathogenic fungi, leading to disease incidences at 48.4% and 50.0%, respectively.【Conclusion】However, C. destructans and C. didynum were considered as two of the most important fungi causeing Panax notoginseng root-rot diseases because of their wide distribution, high frequency of isolation, and close relationship with dominant symptom.
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    Cited: Baidu(100)
    Study on Evaluation/Measurement Method for China's Rural Informatization
    Scientia Agricultura Sinica    2008, 41 (4): 1012-1022.   DOI: 10.3864/j.issn.0578-1752.2008.04.010
    Abstract1594)      PDF (249KB)(1241)       Save
    【Objective】 The paper established a set of methods suitable for China to assess the informatization level in rural areas and analyzed the status quo of rural informatization in different parts of China.【Method】 The study established a synthetical index method, and the process is indicator identification, data collection, data standardization and indexation.【Results】 The national average level of the rural informatization is 99.69. The top six places are Shanghai and Beijing municipalities, Guangdong, Hebei, Zhejiang and Jiangsu provinces. The informatization index of shanghai is 259.15, which is 160% higher than the average level and 971% of the level of Tibetan.【Discussion】 The building of infrastructures for rural informatization and the application of agricultural Information Technology (IT) has played an evident role in the process of informatization construction of rural areas. However, the gap of rural informatization development between Eastern and Western China is still wide.
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    Cited: Baidu(100)
    Relationship Between Diurnal Changes of Net Photosynthetic Rate and Environmental Factors in Leaves of Zizania latifolia
    ,,,
    Scientia Agricultura Sinica    2006, 39 (03): 502-509.   DOI: 10.3864/j.issn.0578-1752.at-2005-6313
    Abstract1189)      PDF (618KB)(1248)       Save
    【Objective】 Relationship between diurnal changes of net photosynthetic rate and environmental factors in leaves of Z. latifolia were studied. The results provided scientific basis for using resources of Z.latifolia.【Method】Diurnal changes of net photosynthetic rate and environmental factors in leaves of Z.latifolia were measured using Li-6400 portable photosynthesis system. The relationship between net photosynthetic rate and environmental factors were analyzed by correlation analysis.【Result】The net photosynthetic rate was in the range of 15.0-21.5 ?mol·m-2·s-1 in un-folding leaves of Z.latifolia. Light compensation point of photosynthesis of Z.latifolia in un-folding leaves was 45 ?mol·m-2·s-1. Light saturation point of photosynthesis was 1 040 ?mol·m-2·s-1. Diurnal changes of the net photosynthetic rate, stomatal conductance and transpiration rate were all one-peak curve in leaves of Z.latifolia. The peak of net photosynthetic rate was measured at 11:00 a.m., the average net photosynthetic rate in leaves of Z.latifolia at 8:00-11:00 was higher 4.7 ?mol·m-2·s-1 than at 13:00-16:00. The peaks of stomatal conductance and transpiration rate were measured at 13:00 and 14:00 p.m. During a day, the net photosynthetic rate was significantly positively correlated with photo flux density (PFD) at 5:00-11:00 a.m. and 15:00-19:00 p.m. Correlation coefficient were 0.9874** and 0.9321**, respectively. The net photosynthetic rate showed little positive correlation with PFD at 11:00-15:00. The correlation coefficient was 0.4440. The net photosynthetic rate showed significantly positively correlated with temperature at 5:00-11:00 a.m. and 15:00-19:00 p.m. The correlation coefficients were 0.9617** and 0.9852**, respectively. The net photosynthetic rate was significantly negatively correlated with temperature at 11:00-15:00. The correlation coefficient was -0.8110*. The net photosynthetic rate was significantly positively correlated with stomatal conductance, and was significantly negatively correlated with intercellular CO2 concentration. The correlation coefficients were 0.7936* and -0.8026*, respectively. Stomatal conductance and transpiration rate were significantly positively correlated with PFD. The correlation coefficients were 0.9104** and 0.7858*, respectively. 【Conclusion】Light compensation point of photosynthesis of Z.latifolia in un-folding leaves is lower, but light saturation point of photosynthesis is higher. Z.latifolia is adaptable widely to photo flux density and is a typical heliophyte. Photo flux density and air temperature are major environmental factors influencing diurnal changes of net photosynthetic rate.
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    Cited: Baidu(97)
    The Role of CBF Cold Response Pathway Gene in Heat Treatment-Induced Chilling Tolerance in Banana Fruits
    WANG Hai-bo, LI Lu, SU Xin-guo, ZHANG Zhao-qi, PANG Xue-qun
    Scientia Agricultura Sinica    2016, 49 (14): 2763-2771.   DOI: 10.3864/j.issn.0578-1752.2016.14.010
    Abstract431)   HTML2)    PDF (789KB)(381)       Save
    【Objective】The objective of this study is to investigate the role of C-repeat binding transcription factor (CBF) cold-resistance pathway in heat treatment -induced chilling tolerance in banana fruits and to provide reference for the study of the signal transduction of CBF cold response pathway in banana fruits.【Method】The sequences of 7 genes related to CBF cold response pathway were selected from the banana genome database (http://banana-genome-hub.southgreen.fr/), and then specific primers were designed respectively. Analysis of these 7 genes’ expression patterns of the heat-induced chilling tolerance in banana fruits was conducted using quantitative real-time PCR.【Result】The expression of MaICE gene of banana fruit increased rapidly and reached the maximum level at 7℃ for 1 hour. The expression of DREB (MaDREB1D, MaDREB1E, MaDREB1G and MaDREB3) genes displayed a peak at 7℃ for 1 hour. The expression of MaCOR413 gene had a peak at 7℃ for 4 hours. These results indicated that the CBF cold response pathway (ICE-CBF-COR pathway) exist in banana fruit during cold storage at 7℃. The expression of 7 gene related to CBF cold response pathway reached the maximum levels at 0.5 hour after heat treatment (52℃ 3 min). Furthermore, when the heat treated banana fruits storage at 7℃ for 5 days, the expressions of MaDREB1D, MaDREB1E, MaDREB2C, MaDREB3 and MaCOR413 genes were higher than the non-heated control.【Conclusion】 MaICE, DREB, and MaCOR413 increased in turn when banana fruits stored at 7℃. The CBF cold response pathway exist in banana fruits during cold storage at 7℃. Enhancement of gene expression related to CBF cold response pathway may be involved in chilling tolerance induced by heat treatment in banana fruits.
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    Cited: Baidu(97)
    Mapping QTL for Seedling Root Traits in Common Wheat
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    Scientia Agricultura Sinica    2005, 38 (10): 1951-1957.   DOI: 10.3864/j.issn.0578-1752.at-2004-2903
    Abstract1507)      PDF (220KB)(1279)       Save
    A doubled haploid (DH) population with 150 lines, derived from a cross between two common wheat varieties Hanxuan10 and Lumai14, was used in this research. Several root traits including root number (RN), maximum root length (MRL), root fresh weight (RFW), root dry weight (RDW), ratio of root fresh weight to shoot fresh weight (RFW/SFW) and ratio of root dry weight to shoot dry weight (RDW/SDW) per plant of hydroponic seedlings were measured under water stress and control conditions, respectively. Quantitative trait loci (QTL) and G×E interactions for these traits were detected using mixed-model-based composite interval mapping method. A total of 11 additive QTL and 15 pairs of epistatic QTL associated with root traits were mapped on all chromosomes except 5A, 4B, 2D, 6D and 7D. Among these QTL, 3 QTL with additive effects and 2 pairs of epistatic QTL controlling root number, 3 QTL with additive effects and 3 pairs of epistatic QTL controlling maximum root length, 2 QTL with additive effects and 2 pairs of epistatic QTL controlling root fresh weight, 2 QTL with additive effects and 3 pairs of epistatic QTL controlling root dry weight, 2 pairs of epistatic QTL controlling ratio of root fresh weight to shoot fresh weight and 1 QTL with additive effects and 3 pairs of epistatic QTL controlling ratio of root dry weight to shoot dry weight were detected. One additive QTL × environment and three pairs of epistatic QTL × environment interaction effects were also identified. The possibility of using marker-assisted selecting root traits and drought tolerance in wheat was discussed.
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    Cited: Baidu(94)
    EST-Markers Flanking the Rice Bacterial Blight Resistance Gene Xa23 and Their Application in Marker-Assisted Selection
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    Scientia Agricultura Sinica    2005, 38 (10): 1996-2001.   DOI: 10.3864/j.issn.0578-1752.at-2005-5172
    Abstract1157)      PDF (302KB)(1378)       Save
    A F2 population, with 2 562 individuals, of JG30/CBB23 was constructed for molecular mapping of the bacterial blight resistance gene Xa23 in rice. Inoculation test of the F2 plants showed that the segregation ratio of resistant and susceptible fits to 3:1. Based on the amthors previous mapping of Xa23 gene, 12 EST markers from Rice Genome Program (RGP) database were surveyed in the susceptible F2 plants and two markers, C189 and CP02662, were found flanking the Xa23 gene, with genetic distance of 0.8cM and 1.3cM, respectively. These two EST markers were successfully used in rice breeding program. The results showed that efficiency of C189 marker-assisted selection (MAS) for Xa23 gene was almost 100%. Three elite hybrid rice restore lines with Xa23 gene and improved bacterial blight resistance have been developed.
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    Cited: Baidu(94)
    The Role of Reactive Oxygen Species in Heat Treatment-Induced Chilling Tolerance in Banana Fruit
    WANG Hai-Bo, PANG Xue-Qun, HUANG Xue-Mei, ZHANG Zhao-Qi
    Scientia Agricultura Sinica    2012, 45 (5): 936-942.   DOI: 10.3864/j.issn.0578-1752.2012.05.014
    Abstract884)      PDF (371KB)(970)       Save
    【Objective】The objective of this study is to investigate the role of reactive oxygen species (ROS) in heat -induced chilling tolerance in banana fruit.【Method】 In this study, 10 μmol•L-1 diphenylene iodonium (DPI), a NADPH oxidase specific inhibitor, was used to inhibit ROS generation in hot water treated fruits. After heat treatment (52℃ for 3 min), banana fruits were stored at 7℃. The chilling injury index, Fv/Fm, contents of H2O2 and  , activities of catalase (CAT) and ascorbate peroxidase (APX), gene expressions of MaCAT and MaAPX genes were determined.【Result】Compared with heat-treated fruits, fruits treated with DPI prior to heat treatment exhibited higher chilling injury index and lower values of Fv/Fm, Moreover, DPI treatment prevented heat-triggered H2O2 and   accumulation, and inhibited the increase of the activities of CAT and APX, and the expressions of MaCAT and MaAPX genes. 【Conclusion】 It is suggested that pre-treatment with DPI prevented the rapid accumulation of ROS induced by heat treatment, which counteracted heat treatment-induced chilling tolerance accordingly had a negative effect on the chilling tolerance induced by heat treatment and showed serious chilling injury symptoms. The reactive oxygen species induced by heat treatment might serve as signal molecules involving in chilling resistance of banana fruits.
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    Cited: Baidu(94)
    Relations Between Cartenoids and Aromatic Components from the Cartenoids in Flue-Cured Tobacco (Nicotinna tobacum L.) Leaves at Different Mature Periods
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    Scientia Agricultura Sinica    2005, 38 (09): 1882-1889.   DOI: 10.3864/j.issn.0578-1752.at-2005-5240
    Abstract868)      PDF (455KB)(1384)       Save
    The quantitative determination results on cartenoids and aromatic components of the cartenoids in flue-cured tobacco leaves from Panxi region, Sichuan Province at different mature periods. The results showed that the contents of cartenoids decreased gradully during the mature periods of flue-cured tobacco leaves in Panxi region. The contents of aromatic components of the cartenoids in the lugs of flue-cured tobacco leaves increased gradully during the end of mature period, but there were not in cutters. The contents of damascenone increased gradully during the mature period of flue-cured tobacco leaves from Panxi region, but the contents of dihydroactinolide decreased gradully. The content of β-inone was little during the mature period of flue-cured tobacco leaves and it was non at the end. The contents of megastigmatrienones increased during the mature period.
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    Cited: Baidu(93)
    Analysis and Comparison of the Effects of Plastic Film Mulching and Straw Mulching on Soil Fertility
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    Scientia Agricultura Sinica    2006, 39 (05): 1069-1075.   DOI: 10.3864/j.issn.0578-1752.at-2005-5566
    Abstract1538)      PDF (409KB)(1093)       Save
    【Objective】The characteristics of effects of plastic film mulching (PM) and straw mulching (SM) on soil fertility were compared for their selective utilization.【 Method】The effects of PM and SM on soil moisture, temperature, nutrients, and microorganisms were studied in pot and field experiments.【Result】Both of SM and PM had significant moisture-keeping capacity. SM increased soil moisture from the surface to the deep layers, but PM only increased soil moisture in the surface layer and the soil moisture decreased significantly in the deeper layers. PM also increased soil temperature significantly, and the soil temperature in SM treatment was lower than that in CK in the corn growing period, but the soil temperature in PM treatment was lower than that in SM treatment in winter season. SM increased soil organic matter and available N, P, and K to varying degrees and PM didn't, while soil organic matter in the surface layer decreased in PM treatment. SM and PM increased the quantities of bacteria, fungus, and actinomyces in soil, and the increases of soil microorganisms were bigger in SM treatment than in PM treatment. 【Conclusion】Plastic film should be selected when the aim of mulching is to increase temperature. The effect of SM is better than that of PM when the aim of mulching is to keep soil moisture. SM also has the roles of increasing soil nutrients and bio-activity.
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    Cited: Baidu(92)
    Spatial Variability of Organochlorine Pesticides (DDTs and HCHs) in Surface Soils of Farmland in Beijing, China
    ,,,
    Scientia Agricultura Sinica    2006, 39 (7): 1403-1410.   DOI: 10.3864/j.issn.0578-1752.at-2006-7106
    Abstract1180)      PDF (689KB)(1313)       Save
    【Objective】 The spatial variation characteristics of 1,2,3,4,5,6-hexachlorocyclohexane (HCH),1,1,1-trichloro- 2,2-bis (p-chlorophenyl) ethane (DDT) and their isomers and metabolites concentration in surface soils of farmland were studied based on the survey of 131 sampling points of Beijing plain area. 【Method】Data were analyzed with the traditional statistical analysis method, the geo-statistical analysis with semivariogram structure and model fitting, the ordinary Kriging and the inverse distance weighting method. 【Result】 The traditional statistical analysis indicated that soil residues of total HCH, total DDT and their isomers and metabolites were lognormal distribution, the coefficients of the variation of all the observed items belonged to the strong degree. According to the geo-statistical analysis with semivariogram structure and model fitting, the soil residues of -HCH, -HCH and the total HCH had no spatial variation structure, while other isomers, metabolites and total DDT had space variation structure and variances may fit the exponential model or the Gaussian model, separately. The variation ranges of α-HCH, the total DDT and its isomers were larger than 18 km, which was relatively higher compared to 2.73 km for -HCH. The trend analysis indicated that all the DDT isomers, metabolites and the total DDT had the obvious tendency effect. But for HCH, only isomers -HCH and -HCH had a slight tendency effect. The contour maps of organochlorine pesticide residues were obtained using the Ordinary Kriging and the Inverse Distance Weighting Method. Based on those maps, the spatial distribution of organochlorine pesticide residues was analyzed.【Conclusion】The results indicated that HCH concentration in all 131 soil samples and DDT concentration in 85% of soil samples were lower than 0.05 mg·kg-1, and reached the first level of China's "Soil Environment Quality Standard" (GB15618-1995). The organochlorine pesticides pollution was generally slight in farmland soil of Beijing plain area.
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    Cited: Baidu(88)
    Effect of Alternate Partial Root-Zone Drip Irrigation on Yield and Water Use Efficiency of Cotton
    ,,,
    Scientia Agricultura Sinica    2005, 38 (10): 2061-2068.   DOI: 10.3864/j.issn.0578-1752.at-2005-5363
    Abstract973)      PDF (408KB)(1135)       Save
    Afield experiment was conducted in the oasis region of Shiyang River basin, Gansu Province to research the effect of alternate partial root-zone drip irrigation(ADI) and conventional drip irrigation(CDI) on soil water distribution, cotton growth, yield and water use efficiency(WUE). The results showed that ADI provided smaller stomata opening to reduce the useless luxury transpiration loss, the height of cotton under ADI was restricted under low irrigation level, but not significant under high level. Results showed that compared with CDI, seed cotton yield under ADI increased by 21.1% with total water use efficiency and irrigation water use efficiency being improved by 17.9% and 20.9%, respectively. Results also showed that seed cotton yield under ADI had no significant difference with 30.8% water being saved. It suggesteds that ADI is a practiced irrigation method which should be researched and applied in cotton producing of arid areas.
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    Cited: Baidu(85)
    Resistance of cry1Ac + SCK Transgenic Rice and Its Filial Generation to the Rice Leaf Roller Cnaphalocrocis medinalis
    Scientia Agricultura Sinica    2005, 38 (04): 725-729.   DOI: 10.3864/j.issn.0578-1752.at-2004-2784
    Abstract1254)      PDF (309KB)(946)       Save
    Field evaluations were conducted to investigate the resistance of cry1Ac + SCK transgenic rice and its filial generation to the rice leaf roller Cnaphalocrocis medinalis. The results indicated that two transgenic rice lines of MSA and MSB inserted with the combination of cry1Ac and SCK were highly resistant against the rice leaf roller, Cnaphalocrocis medinalis, and the progenies from crosses between cry1Ac and SCK transgenic rice and conventional rice varieties, 21S/MSB and II-32A/MSB showed high resistance to leaf roller C. medinalis. The number, percentage of rolled leaves and leaf-rolled plants as well as plants with C. medinalis of MSA, MSB, 21S/MSB and II-32A/MSB were remarkably lower than those of their conventional control rice varieties, respectively.
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    Cited: Baidu(85)
    The Possible Effects of Global Warming on Cropping Systems in China Ⅹ. The Possible Impacts of Climate Change on Climatic Suitability of Spring Maize in the Three Provinces of Northeast China
    ZHAO Jin, YANG Xiao-guang, LIU Zhi-Juan, LV Shuo, WANG Jing, CHEN Fu
    Scientia Agricultura Sinica    2014, 47 (16): 3143-3156.   DOI: 10.3864/j.issn.0578-1752.2014.16.003
    Abstract544)   HTML5)    PDF (823KB)(851)       Save
    【Objective】The variabilities of distribution patterns of spring maize climatic suitability in the three provinces of Northeast China under climate change were studied, and the results will provide a scientific basis for spring maize cropping distribution in the region. 【Method】In this research, the year 1981 was taken as a time node and divided the period 1961-2010 into two sub-periods. The historical climate data from 74 meteorological stations in these three provinces from 1961 to 2010 were used. According to the agro-meteorological indices, the possible northern limit changes of spring maize in Northeast China were analyzed. The rain-fed yields in each station in the potential cropping region of spring maize were assessed by APSIM-Maize model year by year. On the basis of statistical methods, the variabilities of the rain-fed yield level and stablity zones were investigated. In summary, the variability of distribution patterns of spring maize climatic suitability were studied. 【Result】In the period from 1981 to 2010, the possible northern limit of spring maize moved with a northwestward shift of 158.3-285.8 km, and the possible planting area increased by 3.87×104 km2 (4.91% of the whole land area in Northeast China) than during the period from 1961 to 1980. During the period 1981-2010, the percentage of the very high, high and moderately high rain-fed yield zones of spring maize in the possible planting area increased from 81.14% to 86.66%, but the percentage of the very high, high zones decreased from 36.61% to 34.82% and the moderately high zone increased from 44.53% to 51.85%. Meanwhile, the percentage of the marginally high zone decreased from 18.86% to 13.34%. Generally, the rain-fed yield per unit area reduced by 40 kg•hm-2 in the research area. However, the total rain-fed yield increased by 7.0% with possible planting area increase, especially the high and moderately high rain-fed yield zones. The percentage of the very stable, stable and moderately stable rain-fed yield zones of spring maize in the possible planting area increased from 80.20% to 89.28%. Meanwhile, the percentage of the very stable and stable rain-fed yield zones increased from 40.97% to 49.97%, but the percentage of the marginally stable rain-fed yield zone decreased from 19.80% to 10.72%. The percentage of the suitability and moderately suitable climatic zones increased from 61.09% to 83.00%, but the percentage of the very suitable climatic zone decreased from 18.83% to 6.67%. Meanwhile, the percentage of marginally suitability zone decreased from 20.08% to 10.33%. The rain-fed yield per unit area obtained stably reduced by 171 kg•hm-2 in the research region. However, the total rain-fed yield obtained stably increased by 2.6% with possible planting area increase, especially the suitable and moderately suitable climatic zones. 【Conclusion】Under the background of climate change, the possible northern limit of spring maize moved northwestward with an increasing possible planting area in Northeast China. If there were no changes of varieties, cultivation and management, the percentage of the very high rain-fed yield zones in the possible planting area decreased and the yield per unit area reduced. However, the total rain-fed yield increased with the possible planting area increase. The stability of rain-fed yield increased with a greater percentage of the very stable and stable rain-fed yield zones in the possible planting area increased. In the potential cropping area of spring maize in Northeast China, the percentage of the climatic suitability and moderately suitability zones increased, but the percentage of the very suitable climatic zone decreased. The rain-fed yield per unit area obtained stably reduced. However, the total rain-fed yield obtained stably increased with the possible planting area increase in the research region, especially the suitable and moderately suitable climatic zones.
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    Cited: Baidu(85)
    The analysis of conservation tillage in China----conservation tillage and crop yield: reviewing the evidence
    Scientia Agricultura Sinica    2007, 40 (9): 1914-1924.   DOI: 10.3864/j.issn.0578-1752.at-2006-8060
    Abstract1535)      PDF (337KB)(592)       Save
    【Objective】Conservation tillage (CT) also be referred to as resource-efficient / resource effective agriculture,it is primarily used as a means to protect soils from erosion and compaction, to conserve moisture and reduce production costs, have become the most important measures of sustainable agriculture development. Research advances in the conservation tillage of china on recent years were reviewed in this paper.【Method】Based on papers published, the current researches progress on conservation tillage (CT) of crop production in china were summarized and analyzed. All these aspects are reviewed but detailed information of conservation tillage is spares and disparate from China studies.【Result】It was showed that conservation tillage is a relatively new concept but widely adopted in china and had considerable benefits. Since studies have been conducted at the catchment scale, therefore some findings must be treated with caution until the can be verified at a larger scale and for a greater range of climatic, cropping and soil conditions.【Conclusion】Conservation tillage should be put forward in order to establish reasonable policy of agricultural management. It necessary using integrated system analysis methodologies, by means of long-term field and theoretical experience, and the developed modeling approaches with interdisciplinary knowledge, to enhance research strength and level for improving and promoting sustainable agricultural.
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    Cited: Baidu(85)
    Study on the site-specific nitrogen management of rice in cold area of northeastern China
    ,,,
    Scientia Agricultura Sinica    2005, 38 (09): 1761-1766.   DOI: 10.3864/j.issn.0578-1752.at-2005-5440
    Abstract940)      PDF (374KB)(1159)       Save
    Site-specific nutrient management (SSNM) technology was introduced from International Rice Research Institute (IRRI) to solve the problems in fertilizer application on rice in cold area. A plot experiment showed that there were significantly positive correlations (P﹤0.01)between chlorophyll meter values (SPAD values) and N content in leaves, leaf color chart(LCC)values at panicle initiation and heading stages. Therefore 38-40 was considered as the critical SPAD value, and 3.5 was the critical LCC value for N application. Compared with farmers′ fertilization practice (FFP), the site-specific nitrogen management reduced the total N input by 25%, and increased the 1000-grain weight by 0.75 g, and significantly increased fertilizer-N use efficiency. The results suggested that SSNM has a great potential for reducing N input without cutting down the grain yield. SSNM is a valid agricultural approach for applying N fertilizer on rice in cold area of Northeastern China.
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    Cited: Baidu(84)
    Effects of Land Use on Soil Organic C and Microbial Biomass C in Hilly Red Soil Region in Subtropical China
    Wang XiaoLi,,,,,
    Scientia Agricultura Sinica    2006, 39 (04): 750-757.   DOI: 10.3864/j.issn.0578-1752.at-2005-6083
    Abstract1231)      PDF (483KB)(1180)       Save
    【Objective】In order to assess the impacts of land use change on soil organic carbon (SOC) and soil microbial biomass carbon (SMBC), the contents of SOC and SMBC of surface soil samples (0-20 cm) were investigated. 【Method】The dense sampling (the density of sampling for paddy and dry land is 3-4 per ha, for orchard is 2-3 per ha and for woodland is 0.2-0.5 per ha) and the field surveys in Kenfu demonstration area of environmental immigrants of the northwest of Guangxi, a hilly landscape of red soil area of subtropical China were carried out. 【Result】The average contents of SOC, SMBC and the ratio of SMBC and SOC were respectively (17.53±5.02) g·kg-1, (278±174) mg·kg-1 and (1.56±0.84)% in the area, respectively. The average contents of SOC, SMBC and the ratio of SMBC and SOC of the woodland were (17.53±5.02) g·kg-1, (278±174) mg·kg-1 and (1.58±0.39)%, respectively. Compared with the woodland, the contents of SOC and SMBC and the ratio of SMBC and SOC of the paddy field increased by 15.5%, 84.0% and 73.9% (P<0.01); The content of SOC of the dry land (17.50±4.89 g·kg-1) decreased slightly (P>0.05) compared with the woodland, that of SMBC and SMBC/SOC decreased by 29.1% and 24.2% (P<0.01); The content of SOC, SMBC and SMBC/SOC of the orchard decreased by 26.8%, 46.1% and 26.1% compared with the woodland (P<0.01). In addition, there were significant correlations between SOC and SMBC in different land use except the paddy field. 【Conclusion】This study indicated that the conversion of woodland into paddy field increased the accumulation of SOC and the microbial activity evidently in the hilly landscape of red soil area of subtropical China. However, the conversion of woodland into dry land or orchard reduced the content of SOC and the microbial activity to different degrees.
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    Effect of Allelic Variation at the Glu-1 and Glu-3 Loci and Presence of 1BL/1RS Translocation on Pan Bread and Dry White Chinese Noodle Quality
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    Scientia Agricultura Sinica    2004, 37 (09): 1265-1273.   DOI: 10.3864/j.issn.0578-1752.040903
    Abstract1152)      PDF (785KB)(823)       Save
    High molecular weight glutenin subunitins (HMW-GS), low molecular weight glutenin subunits (LMW-GS), and 1BL/1RS translocation play an important role in determining the processing quality in common wheat. 80 and 78 cultivars and advanced lines in trial Ⅰ and trial Ⅱ were sown in two and four environments, respectively. They were used to investigate the effect of HMW-GS, LMW-GS and 1BL/1RS translocation on dough rheological characteristics, pan bread and dry white Chinese noodle quality. Glu-B1, Glu-D1 and Glu-B3 loci play a determinant role in dough rheological characteristics, pan bread and dry white Chinese noodle quality and Glu-A3 locus has slight contribution to them. For gluten strength and loaf volume, at Glu-A1 locus, 1>2*>N;at Glu-B1 locus,7+8>7+9;at Glu-D1 locus,5+10>4+12>2+12;at Glu-A3 locus;Glu-A3d>Glu-A3c> Glu-A3a; at Glu-B3 locus, Glu-B3d>Glu-B3f>Glu-B3b>Glu-B3j. For extensibility and noodle score, at Glu-A1 locus,1>N;at Glu-B1 locus,20>7+9>7+8; at Glu-D1 locus,4+12>5+10≥2+12;at Glu-A3 locus,Glu-A3c≥Glu-A3d>Glu-A3a;at Glu-B3 locus, Glu-B3b≥Glu-B3f>Glu-B3d>Glu-B3j. Lines carrying 1BL/1RS translocation show significantly delerious effect on dough rheological characteristics, pan bread, and dry white Chinese noodle quality.
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    Characteristics of Nutrient Input/Output and Nutrient Balance in Different Regions of China
    LI Shu-Tian, JIN Ji-Yun
    Scientia Agricultura Sinica    2011, 44 (20): 4207-4229.   DOI: 10.3864/j.issn.0578-1752.2011.20.009
    Abstract1573)      PDF (667KB)(3033)       Save
    Clearance of nutrient input/output and balance in farmland in different regions of China is critical for nutrient management, scientific distribution and application of fertilizer resources, and improving nutrient use efficiency, etc. Based on existed literatures this paper systematically analyzed and discussed the current nutrient resources and application status, estimated the amount of manures, crop straws and their potential amount of nutrients NPK. The characteristics of nutrient input, output and balance in different regions of China were analyzed and evaluated.  Strategies and suggestions on nutrient management were discussed based on the existed issues of nutrient input and output.
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    Simulation of Leaf Area and Dry Matter Production in Greenhouse Tomato
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    Scientia Agricultura Sinica    2005, 38 (08): 1629-1635.   DOI: 10.3864/j.issn.0578-1752.at-2005-5179
    Abstract1046)      PDF (352KB)(1479)       Save
    A simulation model for greenhouse tomato leaf area was developed based on the product of thermal effectiveness and PAR (TEP). Then a process based greenhouse tomato dry matter production simulation model was developed by integrating the greenhouse tomato leaf area simulation model. The model was validated by independent experimental data from Shanghai and Nanjing. The results showed that the model can predict leaf area and total dry weight of greenhouse tomato more accurately than traditional models, which calculates leaf area (LA) with specific leaf area (SLA) and growing degree day (GDD). When using the model based on TEP, the coefficient of determination (R2) and the root mean squared error (RMSE) between simulated and measured leaf area (LA) based on the 1:1 line are 0.9743 and 0.0515 m2·plant-1, respectively. When using the model based on TEP, the R2 and RMSE between simulated and measured total dry weight based on the 1:1 line are 0.9360 and 522.7104 kg·ha-1, respectively. For the prediction of plant total dry weight, the prediction accuracy of TEP based model is 56% and 72%, respectively, higher than that of GDD and SLA based model.
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    Genetic Variation in Fifty-Three Maize Inbred Lines in Relation to Drought Tolerance at Seedling Stage
    Scientia Agricultura Sinica    2007, 40 (4): 665-676.   DOI: 10.3864/j.issn.0578-1752.at-2006-7329
    Abstract1780)      PDF (482KB)(1434)       Save
    Abstract: In the study, the genetic variation in 53 maize inbred lines in relation to drought tolerance was characterized using leaf relative moisture content, leaf water conservation, MDA content and seedling survival rate. Fifty-three inbred lines were evaluated for drought responses in greenhouse under water-stressed and well-watered conditions during 2005 in Beijing, China. The evaluation resulted in identification of 13 drought-tolerant, 16 moderately tolerant and 24 susceptible inbred lines, respectively. Under water-stressed condition, drought tolerant lines were found to show higher relative moisture contents, water conservation and lower MDA contents, while the cases reversed for drought susceptible lines. Leaf relative moisture content and water conservation were two important traits indicating drought responses at seedling stage in maize. The diversity at DNA level was investigated by 63 SSR markers. The total number of alleles was 245, and a mean polymorphism information content was 0.596. The UPGMA analysis showed that 53 inbreds could be classified into 6 subgroups (Lancaster, BSSS, PA, Luda Red Cob, Sipingtou and PB), which were generally consistent to their known pedigree records and breeder’s experiences. Comprehensive differences were observed on the mean of leaf relative moisture contents, leaf water conservation and seedling survival rate among the six sub-groups with relatively high level for BSSS, Sipingtou and PB. These three sub-groups were identified as the important sources of drought tolerance. Twenty-one SSR marker alleles were significantly associated with drought tolerance, which could be employed for evaluating the inbred lines of maize to drought responses at DNA level.
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    Physiological Effects of Exogenous Nitric Oxide in Tomato Seedlings Under NaCl Stress
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    Scientia Agricultura Sinica    2006, 39 (03): 575-581.   DOI: 10.3864/j.issn.0578-1752.at-2005-5825
    Abstract1241)      PDF (376KB)(1253)       Save
    【Objective】The purpose of this paper is to clarify the protective effects of nitric oxide (NO) on seedling growth and leaf oxidative damage in NaCl stressed tomato (Lycopersicon esculentum Mill.). 【Method】Under 100 mmol·L-1 NaCl stress condition, the effects of sodium nitropprusside (SNP, an exogenous nitric oxide donor) at the concentrations of 0.05-0.8 mmol·L-1 on the growth, leaf protective enzymatic activities and oxidative damage in tomato seedlings were investigated.【Result】The best effect on the alleviation of NaCl stress damage was observed in the treatment of 0.1 mmol·L-1 SNP. At this concentration, the seedling growth, chlorophyll content, activities of protective enzymes (including SOD, POD, CAT and APX) in leaves, and contents of proline and soluble sugar in leaves were significantly increased, while malondialdehyde (MDA) content and O2- producing rate in leaves were significantly decreased.【Conclusion】The above results indicated that dosage effect of exogenous nitric oxide donor (SNP) existed on the alleviation of NaCl stress in tomato seedlings, and the best alleviating effect on NaCl stress damage was 0.1 mmol·L-1 SNP, which elevated the salt tolerance of plants.
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    Effects of Application of Different Types of Cake Fertilizer Combined with Chemical Fertilizer on the Flavor Quality of the Flue-cured Tobacco Leaves
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    Scientia Agricultura Sinica    2006, 39 (06): 1196-1201.   DOI: 10.3864/j.issn.0578-1752.at-2005-6147
    Abstract1232)      PDF (294KB)(1332)       Save
    【Objective】The purpose of this experiment is to research the effects of application of different types of cake fertilizer combined with chemical fertilizer on the flavor quality of the flue-cured tobacco leaves. 【Mothod】The field experiment was done to investigat the contents of the petroleum extracts, chemical and aroma components of flue-cured tobacco leaves by applying different types of cake fertilizer combined with chemical fertilizer. 【Result】The contents of petroleum extracts in leaves were significantly increased in the four cake fertilizer treatments compared with chemical fertilizer treatment . The contents of aroma components in leaves were also increased in the four treatments. High quality leaves containing the suitable ratio of nicotine and reducing sugar could be obtained by the sesame cake treatment. The sensory evaluation indicated that the higher flavor quality of leaves could be obtained by the treatment. The leaves in cake fertilizer treatment had the characteristics of good aroma quantity, full aroma quality, small odor, suitable irritation, comfortable lingering smell, mild smoke and good combustibility. 【Conclusion】So the higher sensory smoking scores was gained in the cake fertilizer treatment. Consequently 50% of sesame cake N added with 50% of chemical fertilizer N is the optimum combination in tobacco-growing region of Henan Province.
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    Advances and Prospects in Research of Biochar Utilization in Agriculture
    CHEN Wen-Fu, ZHANG Wei-Ming, MENG Jun
    Scientia Agricultura Sinica    2013, 46 (16): 3324-3333.   DOI: 10.3864/j.issn.0578-1752.2013.16.003
    Abstract1054)      PDF (610KB)(2865)       Save
    Biochar has a bright prospect due to its good structure, physicochemical properties and broad raw materials of its production. It has already been a hotspot in the fields of agriculture, energy and environment. The influences of biochar were reviewed comprehensively on soil, crops, agricultural eco-system, and its important roles in food security of China. The application value and industrialization of biochar in agriculture from the low-carbon, recycle and sustainable point of view were discussed. Utilization of biochar would play much more important roles in improving soil obstacles and increasing crop production capacity of soil, which will benefit the sustainable development of agriculture and the national food security of China. At the end, the prospective of biochar industrialization and development in China were proposed, which will provide relevant references for the well development of biohcar industry.
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    Studies on Microbial Population Dynamics in the Cucumber Rhizospheres at Different Developmental Stages
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    Scientia Agricultura Sinica    2004, 37 (10): 1521-1526.   DOI: 10.3864/j.issn.0578-1752.041020
    Abstract1141)      PDF (513KB)(674)       Save
    The microbial population dynamics in the rhizospheres of cucumber was studied by cultivation and culti- vation-independent analysis based on directly extracted DNA. Rhizosphere samples were taken at 2nd, 4th, 7th and 10th week after the seeds were planted, which was positively related to the corresponding date of cucumber growth stages. Results showed that the total number of bacteria, fungi and actinomyces began to rise at planting and quickly reached its peak at seedling or flowering period, but decreased slightly later. Bacterial population in rhizosphere was higher than that of corresponding control except certain periods, while both showed the similar change trend at all stages. Nitrogen fixing bacteria, nitrogen-fixing bacteris and ammonifiers showed the same change tendency in population as bacteria and actinomyces did while cellulose decomposing microbes had the contrary rhizosphere effects as cucumber developed. There was a positive correlation between the rhizosphere microbe population and cucumber development. PCR was employed to amplify V3 region of 16SrDNA, then the products were subjected to denaturing gradient gel electrophoresis (DGGE). DGGE profile indicated that a few of microbe species lived stably in the farmland, but some were affected in population due to cucumber growth. Significant difference was observed in rhizosphere and control soils especially for the seedling and flowering samples. Few prominent bands in DGGE patterns which displayed stronger or less illumination means the bacteria represented had great population change in that period. This phenomenon indicated that flowering cucumber heavily affected rhizosphere bacteria, or the bacteria, most probably uncultured bacteria, functioned specially for cucumber flowering. Most detected bands with no illumination change in DGGE were likely to represent the indigenous microbles that were essential for constructing and stabilizing farmland microecological environment.
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    Development of Potato Industry and Food Security in China
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    Scientia Agricultura Sinica    2005, 38 (02): 358-362.   DOI: 10.3864/j.issn.0578-1752.at-2004-2094
    Abstract1321)      PDF (206KB)(1686)       Save
    Under the pressures of population increase, arable land decrease, water shortage, planting area reduction of three major grain crops (rice, wheat and maize) in recent years, there is a potential crisis in food security in China. As an all-purpose crop with high water utilization efficiency and long industrial chain, the potato planting area has been increased year by year. Compared with the three major grain crops, potato planting area can be further increased by using the winter fallow fields and its yield can be further increased as well. With the development of potato industry, potato will play more and more important roles in alleviating the problem of food security in China.
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    The Interspecific Nitrogen Facilitation and the Subsequent Nitrogen Transfer Between the Intercropped Wheat and Fababean
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    Scientia Agricultura Sinica    2005, 38 (05): 965-973.   DOI: 10.3864/j.issn.0578-1752.at-2004-2995
    Abstract1226)      PDF (246KB)(1454)       Save
    A pot experiment was carried out to investigate the interspecific nitrogen facilitation between the intercropped wheat and fababean. The results from the isotope dilution method showed that wheat competed more fertilizer N than fababean, and fababean depended more on biological nitrogen fixation. 15N recovery rate of wheat with solid barrier, mesh barrier and no barrier was 58%, 73% and 52%, respectively. Nevertheless, 15N recovery rate of fababean was 30%, 20% and 3%, respectively. The results in the mesh barrier also showed that due to competition from wheat for the soil available N, the percentage of fixed N in fababean was enhanced. The percentage of N absorbed by fababean from pots with solid barrier, mesh barrier and no barrier was 58%, 80% and 91%, respectively. Therefore, the complementary N use did exist in wheat-fababean intercropping, and both the interspecific nitrogen competition and facilitation occurred in wheat-fababean intercropping. At last but not the least, the isotope dilution method showed nitrogen transfer occurred from fababean to the associate wheat, and 5% of total N of fababean was transferred to wheat.
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    Mapping of Heading Date QTLs in Rice (Oryza sativa L.) Using Single Segment Substitution Lines
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    Scientia Agricultura Sinica    2005, 38 (08): 1505-1513.   DOI: 10.3864/j.issn.0578-1752.at-2004-2863
    Abstract1299)      PDF (343KB)(1156)       Save
    Heading date (HD) is an important agronomic trait in rice. Appropriate heading date is a prerequisite for attaining the desired yield level in rice breeding programs. It is very important for rice improvement to map heading date quantitative trait loci (QTLs). Single segment substitution lines (SSSLs) containing only one segment of donor chromosome are useful tools for precise mapping of QTLs and for the evaluation of gene action. In this research, the QTLs for heading date on the substituted segments of 52 rice SSSLs derived from 6 advanced backcrosses were identified through t-test for means comparisons between SSSLs and the recipient parent Huajingxian 74. QTLs were detected with a significance of P≤0.001. A total of 20 QTLs were identified on 10 rice chromosomes with the exception of chromosomes 5 and 6. The QTL additive effect ranged from -5.9 to 1.1, and the additive effect percentages of the QTLs ranged from -7.4% to 1.4%. Eight QTLs were mapped in intervals less than 10.0 cM. qHD-3-1, a dominant gene for early heading, has been mapped using a F2 population developed from a cross between a SSSL and Huajingxian 74. In mapping population the segregation ratio of early and late heading plants was in accordance with 3:1. qHD-3-1 was located between microsatellite markers PSM304 and RM569 on the short arm of chromosome 3 at genetic distances of 2.4 cM and 5.1 cM, respectively.
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    Analysis of Genetic Diversity of Sweetpotato Landraces in China
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    Scientia Agricultura Sinica    2005, 38 (02): 250-257.   DOI: 10.3864/j.issn.0578-1752.at-2004-2023
    Abstract986)      PDF (504KB)(1155)       Save
    Genetic diversity of 48 sweetpotato landraces, randomly sampled from 4 regions (Anhui, Fujian, Henan and Guangdong)in China, was analyzed using RAPD, ISSR and AFLP markers. Both 30 RAPD and 14 ISSR primers and 9 AFLP primer combinations generated 227, 249 and 260 polymorphic bands, respectively. AFLPs were better than RAPDs and ISSRs in terms of the number of polymorphic bands detected and the experimental stability. These three molecular markers revealed the similar results that Chinese landraces possess high genetic diversity, and the genetic variation of Guangdong landraces was significantly (at 0.01 level) higher than that of the landraces from other three regions. These results support the hypothesis that China was the secondary center of sweetpotato diversity and also showed that Guangdong was the earliest region where sweetpotato was introduced to China. In this study, the combined RAPDs, ISSRs and AFLPs dataset appeared to be appropriate in resolving the sweetpotato varietal relationships. These landraces can be divided into two groups by UPGMA cluster based on genetic distances, one mainly includes 8 landraces from Guangdong, and another consists of the remaining landraces from Guangdong and landraces from the other three regions. Thus, the utilization of Guangdong landraces should be specially considered in sweetpotato breeding.
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    Analysis of DNA Methylation in Navel Oranges Based on MSAP Marker
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    Scientia Agricultura Sinica    2005, 38 (11): 2301-2307.   DOI: 10.3864/j.issn.0578-1752.at-2005-5655
    Abstract1662)      PDF (268KB)(1428)       Save
    The extent and pattern of cytosine methylation in 24 navel orange cultivars,genomes were assessed by using the technique of methylation-sensitive amplified polymorphism (MSAP). 4.7%-15.0% DNA methylation events were detected in the CCGG sequence of navel orange genomes. In all, 639 fragments were amplified using 18 pairs of selective primers, and 10 of the 18 primers showed 43 DNA methylation polymorphisms. The average proportion of polymorphism(P)was 6.7%. The results demonstrate DNA methylation events occur frequently in navel oranges;methylation patterns vary among the cultivars, and the external cytosine methylation of the CCGG sequence(15.0%) is more than internal one (4.7%). This paper is the first time to analyse cytosine methylation in navel oranges using MSAP, indicating MSAP technique is efficient for detection of cytosine methylation in navel orange genomes.
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