Scientia Agricultura Sinica

Studies of Photosystem Complexes and Chlorophyll Synthesis in Chlorophyll-deficient Rice Mutant W1

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Scientia Agricultura Sinica. 2006, 39(7): 1299-1305 .

Abstract ( 1225 )

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【Objective】Biosynthesis of chlorophyll comprises a number of challenging topics. Chlorophyll-deficient mutants play an important role in exploring biochemical and molecular aspects of its pathway and regulation. 【Method】Chlorophyll- deficient rice, W1, was analyzed by methods of green gel electrophoresis, SDS-PAGE, Western blotting, Northern blotting and detecting precursors of chlorophyll synthesis.【Result】W1 mutant had a significantly decreased amount of chlorophyll, and so did thylakoid proteins, especially Light-Harvesting-Complex II (LHCII) trimers. Western blotting further revealed that LHCII apoproteins in W1 dropped to 1/3 of its amount in wild type. Northern blotting showed a close transcription ability between W1 and its wild type. The contents of chlorophyll synthesis precursors, from δ-aminolevulinic acid (ALA) to protochlorophyllide (Pchlide), equaled to or were greater than those accumulated in W1. However, its chlorophyllide (Chlide), Chl a and Chl b markedly decreased. 【Conclusion】Analysis has proved that the reason for decreased LHCII level in W1 is not due to the reduced transcription and its mRNA accumulation, a possible inefficient synthesis from Pchlide to Chlide primarily attributed to the lowered chlorophylls in W1.

A Comparative Study on Mutagenic Effects of Space Flight and γ-rays Irradiation in Rice

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Scientia Agricultura Sinica. 2006, 39(7): 1306-1312 .

Abstract ( 1149 )

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【Objective】 The experiment was conducted to study the mutagenic effects of space environment on seedling growth in M1, plant height and heading date in M2 in rice. 【Method】 Two types of lines of growth promotion (GP) and growth suppression (GS) were selected from the recombinant inbred lines derived from a cross between a sensitive japonica Lemont and a nonsensitive indica Teqing to compare mutation frequency and mutagenic efficiency for plant height and heading date in M2 generation. 【Result】Space environment resulted in 34.9% higher seedling height in GP group than in the control and 39.1% lower in GS group than in the control, and there was no difference in seed fertility between the two groups. In M2, mutants of plant height and heading date can be induced by space treatment in both the two groups with lower mutation frequency and mutagenic efficiency in GP group than in GS group. There were no significant differences in physiological damages in M1 between the two groups after γ-rays irradiation treatment. Mutation frequency and mutagenic efficiency of heading date in M2 were higher in GS group than in GP group, and opposite was true for mutagenic efficiency of plant height although the mutation frequency varied between the two groups. The mutation frequencies of plant height and heading date induced by space environment were obviously lower than those by γ-rays irradiation, but the mutagenic efficiency was opposite for the most traits. 【Conclusion】 For GP and GS of seedlings induced by space environment, GS had higher mutation frequency and mutagenic efficiency of plant height and heading date than GP in M2.

Assaying Single Nucleotide Polymorphism in Wheat (Triticum aestivum L.) with Allele-Specific PCR

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Scientia Agricultura Sinica. 2006, 39(7): 1313-1320 .

Abstract ( 1235 )

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【Objective】Two hexaploid wheat cultivars (Triticum aestivum L.), Opata85 and W7984, their 111 recombinant inbred lines (RILs), and three diploid relative-species, T. urartu, Ae. Speltoides and Ae. Tauschii were used as plant materials to study the method of assaying single nucleotide polymorphism with allele-specific PCR in wheat. 【Method】 Two SNPs were discovered on B genome by aligning the TaDREB1 genes in two hexaploid wheat cultivars and three diploid relative-species. To type these SNPs, allele-specific primers and their complementary primers were designed using the SNPs as their 3′-end. In addition, we studied the effect of the mismatched bases at the 3′-end of the allele-specific primers on PCR and the optimum PCR system. 【Result】There were distinct effects of the mismatched bases at 3′-end different sites of the allele-specific primers on allele-specific PCR, so did different types of mismatched bases. Moreover, the concentrations of Mg2+, dNTP and Taq DNA polymerase in allele-specific PCR were higher than that in conventional PCR. 【Conclusion】It is feasible to assay SNPs by allele-specific PCR in hexaploid wheat, as long as proper mismatched bases were introduced at 3′-end proper sites of the allele-specific primers and the PCR system was optimized reasonably.

Phenotypic and Genetic Diversity of Rhizobia Associated with Glycyrrhiza spp. Grown in Northern Regions of China

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Scientia Agricultura Sinica. 2006, 39(7): 1321-1327 .

Abstract ( 1478 )

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【Objective】 The biodiversity of rhizobia from Glycyrrhiza spp. in northern regions of China was studied. 【Method】Twenty isolates from Glycyrrhiza spp. were characterized by numerical taxonomy, 16S rDNA PCR-RFLP analysis and BOX-PCR fingerprinting to describe the phenotypic and genetic diversity.【Result】There were two clusters at 85% similarity by numerical taxonomy and 11 strains are separate from reference strains. Fourteen genotypes of tested strains were obtained from the tested 20 strains and analyzed by 16S rDNA PCR-RFLP. The diversity of genomic level was described by BOX-PCR fingerprinting.【Conclusion】 All analyzed results of analysis desmonstrated that the symbiotic bacteria associated with Glycyrrhiza spp. could be found in the genera of Sinorhizobium, Rhizobium and Mesorhizobium.

Progress and Problems of Commercial Production to Transgenic Plants in China

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Scientia Agricultura Sinica. 2006, 39(7): 1328-1335 .

Abstract ( 1418 )

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The current situation of commercial production of transgenic plants in the world and China was summarized in this paper. It showed that the commercial production of transgenic plants in China has made a great progress and has reached an advanced level in some transgenic crops, and that China has become the fifth country in cultivated area of transgenic crops in the world. However, China is still in the developing stage and still has a long way to go as compared with the developed countries. The insufficiency in the study of transgenic plants and the reasons for lagged commercialization were analyzed. The prospects and strategies for industrialization of genetically modified plants were also proposed in the paper.

Growth and Development Characteristics of Super-High-Yielding Mid-Season Japonica Rice

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Scientia Agricultura Sinica. 2006, 39(7): 1336-1345 .

Abstract ( 1660 )

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【Objective】Rice is one of the most important food crops in China. The realization of its super-high-yielding has a great significance for food security of the country. This study investigated the growth and development characteristics of the super-high-yielding (grain yield >11 t·ha-1) of rice.【Method】Four mid-season japonica rice cultivars (including lines), Lianjiajing 2, Huajing 5, 0026 and 9823, were grown in a paddy field. Growth analysis was performed during the growth period, and yield and yield components were determined at maturity.【Result】Super-high-yielding rice had more sipkelets per panicle and higher filled-grain percentage than the high-yielding rice (CK, grain yield 8.98～9.16 t·ha-1). There was no significant difference in 1000-grain weight between the super-high-yielding and the CK. Super-high-yield rice exhibited fewer tillers at the early growth stage (from transplanting to jointing), while a higher ratio of productive tillers to total tillers, as compared with the CK. The leaf area index, photosynthetic potential and dry matter accumulation of the super-high-yielding rice were lower than those of the CK at the early growth stage, and their differences were not significant between the two rice types at heading, and were greater for the former than the later after heading. The root-shoot ratio at each growth stage, root bleedings from heading to maturity, grain-leaf ratio, translocation percentage of the matter from stems and sheaths and harvest index of super-high-yielding rice were greater than those of CK. 【Conclusion】 The indexes for the growth and development of super-high-yielding mid-season rice population were suggested, i. e., total spikelets > 4.5 × 104·m-2, filled-grain percentage > 90%, 1000-grain weight > 26 g; ratio of productive tillers > 80%, leaf area index at heading 7.5-8.0, photosynthetic potential during whole growth period > 5×106 m2·d·ha-1, total dry matter weight at maturity >22 t·ha-1, harvest index > 0.51; grain-leaf ratio (No of spikelets per cm2 leaf area) > 0.58; root-shoot ratio at heading stage >0.25 and the amount of root exudates > 5 g·m-2·h-1. The regulation approaches and key cultivation techniques for raising the super-high-yielding population were discussed.

Prediction of Ensiled Maize Quality Traits with Near Infrared Diffuse Reflectance Spectroscopy (NIDRS)

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Scientia Agricultura Sinica. 2006, 39(7): 1346-1351 .

Abstract ( 1329 )

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【Objective】This study was conducted to investigate the feasibility of measuring in vitro dry matter digestion (IVDMD), neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein (CP) and ether extract (EE) concentrations in ensiled maize by near infrared diffuse reflectance spectroscopy (NIDRS). 【Method】The ensiled stover and whole plant samples from normal oil maize, high oil maize and super oil maize were used to establish NIDRS calibration models of ensiled maize with the techniques based on the principal component space of spectra and partial least square regression (PLS). 【Result】 The results showed that the determination coefficients of cross validation (R2cv) and validation (R2val , in parentheses) of these yielded models were 0.9133 (0.8879), 0.9764 (0.9455), 0.9789 (09635), 0.7294 (0.7333) and 0.9254 (0.9387) for IVDMD, NDF, ADF, EE and CP respectively. The root mean square error of estimation, cross validation and prediction (RMSEE, RMSECV and RMSEP) ranged from 0.26 for CP to 2.23 for NDF. 【Conclusion】 It has been demonstrated that it is feasible to use NIDRS as a rapid and an accurate technique to predict ensiled maize quality traits. These calibration models could meet the needs of silage quality evaluation in livestock industry and screening of various samples in silage maize breeding.

The Monitoring for Sequential Cropping Index of Arable Land in Zhejiang Province Using MODIS-NDVI

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Scientia Agricultura Sinica. 2006, 39(7): 1352-1357 .

Abstract ( 1537 )

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【Objective】 The sequential cropping index of arable land is an important agricultural information, the objective of this paper is that monitor and analyze this parameter, and supply a reference for guiding agricultural production.【Method】Based on the MODIS (moderate resolution imagine spectroradimeter) vegetation data from NASA(National Aeronautic and Space Administration) in America and the actual land use map with a scale of 1﹕2 500 000, using two times differencing, this paper monitors the cropping index of arable land in Zhejiang Province from 2001 to 2004. 【Result】 Within one year, there are principles of the interaction between the time series of NDVI (normalized difference vegetation index) profile and the growing process of crops, this process can be described as planting, seeding, heading, ripe, harvest and so on, and the peak of the time series of NDVI profile indicates that the colony ground biomass reaches the tiptop, so sequential cropping index can deem that equal to the number of peaks of time series of NDVI profile. Based on this principle, the sequential cropping index of all cities in Zhejiang Province was worked out.【Conclusion】It was found that the sequential cropping index in southwest is bigger than northeast in Zhejiang Province in the space. In the time, the sequential cropping index shows the depressed levels from 2001 to 2003 and the value increaseed to some extent in 2004, but the value was low, so there are much potential for the sequential cropping index of arable land in Zhejiang Province in consideration of the geography and the climate in Zhejiang Province.

Cyclobutyl Pyrimidine Dimer Accumulation in Ralation to UV-B Sensitivity in Mung Bean Cultivars

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Scientia Agricultura Sinica. 2006, 39(7): 1358-1364 .

Abstract ( 1419 )

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【Objective】 The purpose of the experiment is to reveal the relationship between cyclobutyl pyrimidine dimers (CPDs) accumulation and UV-B sensitivity in mung bean cultivars. 【Method】 Two mung bean cultivars (Phaseolus raditus L. cv. Qindou-20 and Zhonglü-1) were grown in greenhouse with treatment or without treatment of UV-B radiation (0.4 W·m-2) for four days. The UV-B-induced CPDs in mung bean DNA were quantified by enzyme-linked immunosorbent assay (ELISA) with specific monoclonal antibody and the relationship between CPDs accumulation and the UV-B sensitivity of mung bean seedlings were discussed. 【Result】 The UV-B-induced inhibition of the biomass and net photosynthetic rate of the primary leaves of cultivar Zhonglü-1 were respectively lower than that of cultivar Qindou-20, so that the cultivar Zhonglü-1 was more tolerant to UV-B than the cultivar Qindou-20. Meanwhile, the cultivar Zhonglü-1 had lower CPD accumulation and susceptibility to CPD induction, higher photorepair capacity and same dark repair capacity as compared with the cultivar Qindou-20. 【Conclusion】 Different UV-B sensitivities between two mung bean cultivars may be mainly caused by the differences in CPD accumulation, which are caused by the different susceptibility to CPD induction and the different photorepair capacities. In addition, the different susceptibility to CPD induction between two mung bean cultivars is related to the different levels of UV-absorbing compounds.

Resistance Mechanism to Fulvia fulva of Tomato Transformed with GO Gene

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Scientia Agricultura Sinica. 2006, 39(7): 1365-1370 .

Abstract ( 1124 )

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【Objective】 The aim of the study is to determine the mechanism of resistance to Fulvia fulva of tomato transformed with GO gene.【Method】Superoxidase (SOD), peroxidase (POD), catalase (CAT), phenylalanine ammonialyase (PAL) and polyphenoloxidase (PPO) activities of three transgenic tomato lines and non-transgenic line (CK) were studied after inoculation. 【Result】The results showed that SOD, POD, CAT activities of transgenic tomato lines were much higher than that of non-transgenic tomato and showed a peak earlier than that of non-transgenic tomato line. Moreover the activities of PAL and PPO increased and showed two peaks in three transgenic tomato lines and only one peak in non-transgenic tomato line. 【Conclusion】T1 tomato plants infected with Fulvia fulva showed enhanced disease resistance, delayed disease symptoms and reduced leaf lesions at different levels.

The Causal Microorganisms of Panax notoginseng Root Rot Disease

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Scientia Agricultura Sinica. 2006, 39(7): 1371-1378 .

Abstract ( 1177 )

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【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.

Evaluation of Piemarker Abutilon theophrasti Medic as aTrap Plant in the Integrated Management of Bemisia tabaci (biotype B) in Cotton and Soybean Crops

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Scientia Agricultura Sinica. 2006, 39(7): 1379-1386 .

Abstract ( 1299 )

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【Objective】Piemarker Abutilon theophrasti Medic as a trap plant in the integrated management of Bemisia tabaci (biotype B) in cotton and soybean crops was evaluated during 2004-2005 in Langfang, Hebei Province.【Method】Effects of piemarker as a trap plant were investigated through different planting dates, planting types and insecticide application on the piemarker plants. 【Result】Piemarker plants showed strong attraction to the whitefly adults, with significant differences among the treatments planted on different dates. The whiteflies were firstly found on the early planting piemarker with an attractive rate of 85.2% in early period of cotton/soybean growth, while the piemarker plants sowed in middle and late dates presented high efficiencies to the pest (93.3% and 95.4%) in middle and late season, respectively. There was a positive relationship between the uniformity degree of the piemarker distribution in field and attractive rate. The attractive efficiency from single interplanting piemarker was 3-fold and 7-fold high as compared to the planting types of the strip interplanting and plot interplanting. The insecticide application of 25% thiamethoxam WDG, 5% fipronnil SC, 25% buprofezin WP, 10% beta-cyperethrin LC, and 25% phoxim LC on piemarker plants, showed different control effects on sucking insect pests in cotton fields. The control efficiency ranged from 21.76% - 97.57% for the adult and 27.02% - 74.77% for the nymphs, respectively. Among the insecticides tested, 25% thiamethoxam WDG and 5% fipronnil SC gave best results in terms of maximum mortality of this pest in cotton and soybean crops.【Conclusion】Piemarker as a trap plant in cotton and soybean field can play an important role in the integrated management of B. tabaci.

Effects of Plant Species Switching on Contents and Dynamics of Trehalose and Trehalase Activity of Bemisia tabaci B-biotype and Trialeurodes vaporariorum

Fang Lei,GuiFen Zhang,FangHao Wan,Jun Ma

Scientia Agricultura Sinica. 2006, 39(7): 1387-1394 .

Abstract ( 1356 )

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【Objective】The contents and dynamics of trehalose and trehalase activity of Bemisia tabaci B-biotype and Trialeurodes vaporariorum were evaluated when 【Method】 Their host plant species switched from tomato (an addicted host plant species of both whitefly species, also as the control) to cotton (B. tabaci B-biotype is addicted to it and T. vaporariorum can develop), cabbage (B. tabaci B-biotype is addicted to it but T. vaporariorum cannot survival) and maize (both whitefly species cannot survival) plants.【Result】The trehalose contents of B. tabaci B-biotype and T. vaporariorum decreased when both whitefly species switched from tomato to the three tested plant species, especially to the cotton, decreased by 33% and 25%, respectively. There were no significant differences between the two whitefly species switched to cotton and cabbage plants when the dynamics of trehalose contents were compared. However, switched to non-addicted host, the maize, the recovery ability and stability of B. tabaci B-biotype (112.6%) were more powerful than those of T. vaporariorum (60.8%). The effects of plant species switching on trehalase activity of the two whitefly species were not prominent, but the dynamics of trehalase activity of both were different. The dynamics of trehalase activity of B. tabaci B-biotype were not different when switched to cotton, cabbage or maize plants; however, the differences were observed when T. vaporariorum switched to the same three plant species. The dynamics of trehalase activity of B. tabaci B-biotype and T. vaporariorum on non-addicted maize plant were not significantly different; however, the recovery ability and stability of B. tabaci B-biotype (56.0%) were greater than that of T. vaporariorum (48.4%). 【Conclusion】The present results indicated that the trehalase may be important in the enlargement of host plant species of B. tabaci B-biotype and in the competition between B. tabaci B-biotype and T. vaporariorum.

Micromorphological Features of Old Cultivated and Modern Soil in Guanzhong Areas of Shaanxi Province, North China

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Scientia Agricultura Sinica. 2006, 39(7): 1395-1402 .

Abstract ( 1475 )

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【Objective】 Using the data obtained from the LGT soil profile, this paper attempts to illustrate soil-forming process of modern soil in the Guanzhong areas and its micromorphological features. 【Method】 Micromorphology was observed under a petrographic microscope, and its image was quantitatively measured by LEICAL Qwin software. 【Result】Micromorphological observations of the thin sections show that the minerals assemblage of different horizons very similar, which is mainly composed of Q and Pl. However, there are obvious differences in C/F15?m ratio, mineral content, and coarse features. Pedofeatures mainly consist of clay, calcite, and amorphous Fe. Ap horizon is characterized by abundant needleshaped secondary-calcite, secondary-clay, and earthworm fecal pellet. BC horizon is characterized by the secondary-calcite of large quantity with various shapes. Bt1 and Bt2 horizons are characterized by abundant clay hyopcoatings and a small quantity of secondary-calcite. 【Conclusion】All the results of this research suggest that Earth-cumulic Orthic Anthrosols consist of both the upper Ap horizon, which cause loessal dung and eolian dust deposition, and cultivation occurs simultaneously during the process of Ap horizon-formation, and the lower BC horizon, which is aeolian sedimentary at the time of relative aridity during late Holocene.

Spatial Variability of Organochlorine Pesticides (DDTs and HCHs) in Surface Soils of Farmland in Beijing, China

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Scientia Agricultura Sinica. 2006, 39(7): 1403-1410 .

Abstract ( 1180 )

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【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.

Response of Cmic-to-Corg to Land Use and Fertilization in Subtropical Region of China

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Scientia Agricultura Sinica. 2006, 39(7): 1411-1418 .

Abstract ( 2008 )

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【Objective】 Ratios of microbial biomass C to total organic C (Cmic-to-Corg) could be an indication of a system at a new equilibrium after land use or managements changed. 【Method】 But few researches putted their emphasis on the impacts of land use or management on Cmic-to-Corg. Two small-scaled regions (Pantang region and Kenfu region) and six long-term experiments (1986-2001) in paddy fields were used to investigate the response of Cmic-to-Corg to land use and fertilization in subtropical region of China. 【Result】 The results from PT and KF regions indicated that there was no universal equilibrium Cmic-to-Corg constant in every land use. Mean Cmic-to-Corg amounted to (5.07±1.26)% for paddy field, (2.96±1.60)% for dryland, (2.40±0.34)% for woodland, (1.98±0.89)% for orchard in Pantang region, respectively. The effect of land use on Cmic-to-Corg in Kenfu region was a little different with that in PT region. Mean Cmic-to-Corg amounted (3.01±1.51)% for paddy field, (1.57±0.40)% for woodland, (1.29±0.56)% for dryland, (1.14±0.42)% for orchard, respectively. In both regions, responses of Corg to land uses were similar with Cmic-to-Corg, and the results also showed that anthrostagnic soil (paddy field) was not only in favor of the carbon sequestration but also helpful to the microbial biomass enhancement. Long-term experiments showed that Cmic-to-Corg of paddy soils with chemical fertilizer applied increased in recent 17 years in half of experiments but not significant. With the same amount of N applied, organic matter incorporation including middle-level (30% organic N+70% chemical N) manure, high-level (60% organic N+40% chemical N) manure and straw treatments contributed to the enhancement of microbial biomass in paddy soils, averaged by 6 experiments, Cmic-to-Corg increased by 17.94%, 19.91% and 17.51% (compared with control), respectively. 【Conclusion】Though significant relationships (P<0.01) exists between organic C and microbial biomass C in 6 long-term experiments, but the response of soil organic C to fertilization was not completely the same as that of Cmic-to-Corg. It indicated that Cmic-to-Corg could reflect the changes of Corg, but not precisely.

Effects of drip fertigation strategies and frequencies on yield and root growth of tomato

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Scientia Agricultura Sinica. 2006, 39(7): 1419-1427 .

Abstract ( 1377 )

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Field experiments were conducted in a solar-heated greenhouse to investigate the effects of drip fertigation strategies and frequencies on yield, quality and root growth of tomato. Three fertigation strategies that varied the order in which water and nutrient were applied and three fertigation frequencies of weekly, fortnightly and once every four weeks were tested. Photosynthetic rate was measured during the growing season. At harvest root length density and yield were measured. The experimental results show that fertigation frequencies influence the tomato yield significantly. Yield increased significantly with the increase of fertigation frequency (P=0.012). Yield declined as the fertigation time was transferred towards the end of an irrigation cycle. Both fertigation strategies and frequencies did not influence the quality of tomato significantly. Root length density varied with fertigation frequencies, and the ratio of root length density in different soil layers varied with fertigation strategies. Effect of strategies and frequencies on photosynthetic rate were investigated. Accumulation of photosynthetic rate in the whole growing season were calculated for analyzing the relationship between yield and photosynthesis. The results demonstrated that the yield was highly correlated to accumulation of photosynthetic rate. For the sake of improving yield and quality of tomato, fertigation weekly and the strategy of applying fertilizer as early as possible in the whole irrigation schedule were recommended.

Studies on Induction of Haploid Cucumbers by Irradiated Pollen Pollination and Their Characterization

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Scientia Agricultura Sinica. 2006, 39(7): 1428-1436 .

Abstract ( 1172 )

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【Objective】The aim of the experiment is to systematically investigate the effects of pollination combination, development stage of male flower when subjected to irradiation and the dosage on fruit setting and haploid production of cucumber. 【Method】The methods of irradiated once and pollinated twice plus embryo culture were adopted, 32 different genotypes of cucumber were used as maternal parents and 6 genotypes were used as paternal parents to produce haploid cucumber through γ-irradiated pollen pollination. 【Result】 Totally 48 haploid embryos were successfully recovered from 15 genotypes, and the average percentage of haploid embryo production was 0.77% and the highest was 50.00%.【Conclusion】 No significant influence of male flowers developing stage on fruit setting was found but the haploid embryo production was affected. The irradiation dosage affected fruit setting and haploid embryo production, but there was no significance. The haploid embryo production was affected greatly by different pollination combinations. The experiments from morphological observation, meiotic chromosome behavior and fertility investigation, and some physiological and biochemical measurements indicated that there were significant morphological differences between haploid and diploid. Most haploid plants had no fertility except H2. Meiotic observation on the H2 found the abnormal behavior at every stage, but there was a production of 0+7 gametes produced at very low frequency at anaphase I, which likely produced the fertile gametes. Differences in chlorophyll contents, activation of POD, soluble protein contents were found between haploid and diploid plants.

Breeding and Cytological Identification of a Set of Primary Trisomics in Cabbage

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Scientia Agricultura Sinica. 2006, 39(7): 1437-1442 .

Abstract ( 1110 )

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【Objective】Selection of primary trisomics of the cabbage（Brassica oleracea L. var.capitata L.）is an important foundation for the gene chromosome mapping and other genetic studies. 【Method】 The self fertilization line - 9601 of cabbage was used as material, by using analysis of the root tip cell chromosome number and pollen mother cell chromosome number identification and karyotype, the primary trisomics from the progenies of 3x × 2x in the cabbage were selected. 【Result】Many aneuploid plants with one or two extra chromosomes were obtained and a set of primary trisomics (Tr-1, Tr-2, Tr-3, Tr-4, Tr-5, Tr-6, Tr-7, Tr-8 and Tr-9 in which the Tr-1 and Tr-4 from 2n+2 plants, others from 2n+1 plants ) was acquired from the aneuploid plants. Each trisomic was with some unique characters, such as plant height, plant type, leaf type, size of flower bud and inflorescence.【Conclusion】The triploid crossing by the diploid is a convenient and effective way to select trisomics in cabbage.

Regeneration and Transformation Through Somatic Embryogenesis, and Determination of Cold Stress Tolerance in Ground Cover Chrysanthemum cv. Fall Color

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Scientia Agricultura Sinica. 2006, 39(7): 1443-1450 .

Abstract ( 1342 )

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【Objective】This article aimes at breeding of new materials with tolerance to cold conditions in ground-cover chrysanthemum [Dendranthema grandiflorum (Ramat.) Kitamura]. 【Method】Young leaf explants of the cultivar, Fall color, were used to determine the optimum conditions of both concentration of plant growth regulator and induction time to establish a high frequency regeneration system through somatic embryogenesis. 【Result】The explants incubated for 15 d on IM containing 0.75 mg·L-1 2,4-D generated not only embryo callus tissue, but also somatic embryos. The somatic embryos emerged shoot with 93% of shoot regeneration rate after further regeneration culture. AtDREB1A, a stress-inducible transcription factor, driven by 35S cauliflower mosaic virus (CaMV) promoter was transferred into Fall Color through Agrobacterium-mediated transformation. Seed germination and seedling growth at low temperature, and plant growth in winter cultivated in open-field were much improved in transgenic plants compared to WT plants. 【Conclusion】These results indicate that the authors have established successfully the embryo-generation system of ground-cover cv. Fall color, and have obtained successfully the transgenic lines with tolerance to open-field conditions in winter.

Identification of Cabernet Gernische Wine Age by High-Performance Liquid Chromatography Anthocyanins Fingerprint

junxiang zhang,,

Scientia Agricultura Sinica. 2006, 39(7): 1451-1456 .

Abstract ( 1370 )

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【Objective】 The anthocyanin HPLC fingerprints of aging wines and identification of 6 different vintage of Cabernet Gernische wines were established. 【Method】HPLC analysis: Chromatographic condition was RP-C18 column, pH 1.6 in mobile phases, binary solvent delivery gradient elution, and UV-Vis detection was used at 518 nm. Fingerprint: The relative reserving time and relative area of chromatography peaks were computed, and the relative area of chromatography peaks were arranged according to relative reserving time in turn. 【Result】14 main peaks were separated and used in fingerprints. The chromatography peaks were identified preliminaryly. By using HPLC method, for the first time, the fourteenth peak was separated and it was found that the relative content of this peaks was relevant to the aging of wine closely. The anthocyanin HPLC fingerprints had a big difference from different vintage Cabernet Gernische wines. 【Conclution】 The good reproducibility and stability were shown in this experiment. The method of anthocyanin HPLC fingerprints is feasible for distinguishing the age (vintage) of red wine.

In vitro Production of Porcine Embryo

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Scientia Agricultura Sinica. 2006, 39(7): 1457-1463 .

Abstract ( 1362 )

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In recent years, progress has been achieved in the production of pig embryos through IVM and IVF techniques, However, there are still some problems, and factors restricting the application of the reproductive biotechnology, for example, poor cytoplasmic maturation、highly polyspermy and poor embryo development. This review will focus on porcine oocytes maturation, fertileization and embryo culture.

Effect of Additives on Baled Alfalfa Silage

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Scientia Agricultura Sinica. 2006, 39(7): 1464-1471 .

Abstract ( 1210 )

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【Objective】The studies were conducted to investigate the fermentation and nutrient dynamics of baled alfalfa silage with additives at different storage periods. 【Method】Alfalfa unchoped ensilaged with or without formic acid, previous fermented juice, using small round bales and stretch films. Alfalfa silage was sampled and analyzed. 【Result】The fermentation quality of alfalfa silage could be enhanced by adding formic acid or previous fermented juice. The additives extremely decreased the baled alfalfa silage pH (P<0.01), increased lactic acid content (P<0.05), and reduced the ammonia nitrogen content (P<0.05), and the effect was more evident along with the storage period. The effects of different additives on CP, NDF, ADF, no-protein nitrogen, and acid detergent insoluble nitrogen content of baled alfalfa silage were less than the storage period. 【Conclusion】It is concluded that the baled alfalfa silages treated with formic acid or previous fermented juice can be stored longer so that alfalfa silage can be supplied steadily for animal husbandry.

Study on the Accuracy and Precision of n-Alkanes as Markers for Estimation of Diet Composition and Herbage Intake of Sheep

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Scientia Agricultura Sinica. 2006, 39(7): 1472-1479 .

Abstract ( 1625 )

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【Objective】An experiment was carried out to determine the accuracy and precision of n-alkanes as markers for estimation of feces output, diet composition and herbage intake of sheep, and measure fecal recoveries of n-alkanes in sheep, 【Method】The experiment was carried out at the Inner Mongolia Grassland Ecosystem Research Station of the Chinese Academy of Sciences in autumn 2004. Nine wethers selected from a group at 2-years-old of age were fed with fresh mixtures of Leymus chinensis (30%), Cleistogenes squarrosa (20%) and Artemisia frigida (50%) in known proportions and amounts for 14 days. Artificial QSM capsules were dosed during the experiment. The samples of herbage and feces were collected daily for 7 days and dried for analysing the n-alkane concentration by a gas chromatography. 【Result】The results showed that there was a difference in concentration of n-alkanes among 3 species forages, and fecal recoveries of n-alkanes linear increased with increasing carbon chain lengths. There were significant correlations (P < 0.01) between estimated feces output (r = 0.9994), dietary composition of L. chinensis (r = 0.9913), C. squarrosa (r = 0.9864), A. frigida (r = 0.9999) and herbage intake using n-alkane technique and the actual values. Estimated intakes were 4% (±1.3％) and 7% (±1.3%) lower than the actual intake by sheep based on C33:C32 and C31:C32 n-alkane ratios, respectively, but were not differ significantly (P > 0.05). 【Conclusion】 In conclusion, n-alkane technique can provide an accurate and precise estimation of feces output, diet composition and herbage intake of sheep.

Effects of Intermittent Lighting Schedules on Incidence of Pulmonary Hypertension Syndrome and Pulmonary Vascular Remodeling in Broilers

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Scientia Agricultura Sinica. 2006, 39(7): 1480-1486 .

Abstract ( 1217 )

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【Objective】 The purpose of the present study was to examine the efficacy of imposing intermittent lighting schedules on reduction of the incidence of ascites(or Pulmonary Hypertension Syndrome,PHS)induced by cool ambient temperature and to investigate its effect on the pulmonary vascular remodeling of broiler chickens. 【Method】 A total of three hundred and twenty broilers were randomly allocated to four groups. In one group, the continuous lighting schedule（CL）of 24 h light(L): 0 h dark (D) was maintained, ambient temperature kept normal（normal control group, NC）while in other three groups, the chickens were subjected to cool ambient temperature to induce PHS. The continuous lighting schedule of 24L:0 D (Low temperature control group,LC) and the intermittent lighting (IL) schedule of 21L:3 D(group L1) and 19 L:5D (group L2) were imposed, respectively, from 9 to 30 days of age (From day 30 onwards all groups were kept in continuous lighting). PHS incidence, body weights and feed intake were measured weekly for each group. Heart, Lung and blood samples were taken from 10 randomly selected birds per group at 14, 23, 30, 37 and 44 days of age, for the determination of the ratio of vessel wall area to total area (WA/TA), mean medial thickness in pulmonary arterioles (mMTPA),etc.【Result】The results indicated that the cool ambient temperature could increase morbidity of PHS in broilers, the values of WA/TA and mMTPA also were increased significantly, whereas the intermittent lighting (IL) schedule could successfully decrease the morbidity of PHS induced by cool ambient temperature and the values of WA/TA and mMTPA, which served as describing pulmonary vessel remodeling (P﹤0.05). Birds in IL groups were lighter than that in LC group during light restriction period, but both the final body weights and total feed conversion ratio were not significantly affected by the lighting program in all birds subjected to low temperature. 【Conclusion】It is concluded that introduction of intermittent lighting schedule during the early growing period is of benefit to reduce PHS morbidity induced by cool ambient temperature in fast-growing broilers, and attenuated pulmonary vascular remodeling may be involved in the underlying mechanisms.

Response to Photoperiodical Variation and the Clone of a Photoperiod-Related Gene in Maize

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Scientia Agricultura Sinica. 2006, 39(7): 1487-1494 .

Abstract ( 1319 )

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【Objective】The aim of the research is to study the response to photoperiodical variation, clone the EMF gene in maize and study the expression pattern of this gene. 【Method】 CML288, a tropical inbred line, and Huanzao4, a temperate inbred line, were used as materials to study the response to photoperiodical variation in maize. The two inbred lines were grown in 2 different controlled photoperiod rhythms, 9 h and 15 h. And some CML288 plants grew at one level of photoperiod and then were transferred to the other photoperiodical level at different stages. Developmental stages and leaf numbers were recorded. A photoperiod related gene was cloned using RT-PCR. The expression of the gene in different treated materials was studied. 【Result】Results showed that CML288 was very sensitive to photoperiodical variation, but Huangzao4 was not. The seven-leaf stage is the most sensitive period for CML288 under short-day condition, and the nine-leaf stage on long-day condition. The cloned novel gene contains an open reading frame of 1881bp encoding a putative DNA binding protein of 626 amino acids, which was possessed of a C2H2-type zinc finger motif, two putative nuclear localization signals and an acidic cluster. It expressed or did not differ from different materials. 【Conclusion】The function of the gene might be maintained vegetative development by repressing the flower program genes. Northern blot revealed that it expresses both in the SAM and leaf.

A Study of the Effects of Different Grazing Intensities on Soil Physical Properties of Grassland and Forest Floor -- For Example Hilly and Gully Regions on the Loess Plateau

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Scientia Agricultura Sinica. 2006, 39(7): 1501-1506 .

Abstract ( 1301 )

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【Objective】The objective of this article was to study the changes in soil physical properties with different grazing intensities. 【Method】With grazing field experiment, the effects of different grazing intensities and different types of livestock on physical properties of surface (0-10 cm) soil of grazing grassland and forest land with Caragana korshinskii Kom. were studied at hilly-gully regions on the Loess Plateau -Pianguan, Shanxi Province.【Result】The results showed that grazing intensity directly influenced the physical structure of soil of grazing grassland and Caragana korshinskii Kom. The soil bulk density increased along with the increase of grazing intensity, while water content and soil porosity decreased. Compared with goat selected as grazing livestock, sheep had a lesser that trampling effect on grazing land and the soil bulk density, was relatively small. The water content and soil porosity of the grazing land under sheep is higher than that №under goat. 【Conclusion】 Consequently, the soil properties of the surface layer (0-10 cm) grazing grassland and Caragana korshinskii Kom. are most sensitive to grazing intensity.

Analysis of Two-Dimensional Gel Electrophoresis Patterns of Protein from Posterior Silkgland of Silkworm Bombyx mori on Day 1 and Day 4 in 5th Instar Stage

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Scientia Agricultura Sinica. 2006, 39(7): 1501-1506 .

Abstract ( 964 )

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【Objective】 The posterior silkgland of silkworm is a very important organ where fibroin is synthesized and secreted. Since fibroin constructs silk-filament by amount of 75%-80%, the mechanism of fibroin secretion, cocoon quality and high yield can be elucidated by the study on the posterior silkgland. 【Method】 Using two-dimensional gel electrophoresis (2-DE) and image analysis system, the changes of protein composition in posterior silkgland cell of day 1 (D1) and D4 in the 5th instar stage from various breeds of silkworm Bombyx mori were investigated. 【Result】 Differences were observed between days and breeds and far less than those at the gene level through EST analysis. The change patterns of protein composition from D1 to D4 were diverse in various breeds. 【Conclusion】The results suggest that the secretion of fibroin is regulated by multi-protein. The site and protein for regulation vary with breeds, which leads to the difference of the capacity of fibroin secretion in the posterior silkgland cell between breeds.

Hatchability of Miniature Laying Chicken and Its Hybrids at High Altitude

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Scientia Agricultura Sinica. 2006, 39(7): 1507- .

Abstract ( 1412 )

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【Objective】The hatchability of Miniature Layers and hybrids was investigated and the differences of embryonic, mortality, the ratio of egg water loss, and hatchability at different altitudes were analyzed.【Method】Eggs from four groups of chickens, Miniature Layers (M), Miniature Layers fed in Tibet (MT), Tibetan × Miniature Layers (TM), and Tibetan (T), were incubated at 2 900 m an altitude of 2 900 m (Linzhi, Tibet) and an altitude of 3650 m (Lhasa, Tibet), and their embryonic mortality, water loss and hatchability were measured. 【Result】The hatchability of M and TM at an altitude of 2 900 m was 49.44% and 74.69%, respectively. Although it was fed in high altitude environment, MT did not decrease in water loss, and increased a little in hatchability, as compared with M. At 3 650 m an altitude of 3 650 m the embryonic mortalities of all groups increased, and the hatchabilities and ratios of hatch weight to egg weight decreased; and the hatchability of T was 30.70% while that of M was about 10%. 【Conclusion】The results indicated that the water loss was high, and the hatchability of Miniature Layer was low at high altitude, but the heterosis of hatchability of crosbred of T×M was significant.

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