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Table of Content

    15 September 2012, Volume 45 Issue 18
    CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS
    Molecular Marker Identification of Noodle Quality Related Genes in a Commercial Noodle Wheat from Australia
    LI Shi-Zhao, WU Ling, ZHENG Jian-Min, ZHU Hua-Zhong
    Scientia Agricultura Sinica. 2012, 45(18):  3677-3687.  doi:10.3864/j.issn.0578-1752.2012.18.001
    Abstract ( 791 )   PDF (648KB) ( 611 )   Save
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    【Objective】A commercial noodle wheat from Australia, known as Australian Standard White in China due to its top noodle quality, was a mixture of several genotypes. Noodle quality related genes were identified for providing information of noodle quality improvement to wheat breeding in China. 【Method】A total of 36 selected lines from Australian Standard White population were analyzed with 38 functional markers including high molecular weight glutenin subunits (HMW-GS), low molecular weight glutenin subunits (LMW-GS), 1B/1R translocation, waxy protein subunits, polyphenol oxidase (PPO) activity, yellow pigment content, grain hardness and resistance to pre-harvest sprouting (PHS). 【Results】In the 36 lines, there were 13 genes with positive effects on noodle quality, among which non-1B/1R translocation type and HMW-GS gene Bx7 covered 100%, whereas HMW-GS gene By8, LMW-GS genes Glu-A3b and Glu-B3b, Wx-B1 null type, low PPO activity allele Ppo-D1a, low yellow pigment allele Psy-B1b, soft to medium grain hardness allele Pinb-D1a and PHS resistant gene Vp-1Bc had frequencies over 80%. Out of the 36 lines, 12 genotypes were found, among which genotype 2 predominated in the highest frequency up to 63.9%, which covered the most of refered positive genes such as HMW-GS genes Bx7 and By8, LMW-GS genes Glu-A3b and Glu-B3b, low PPO activity gene Ppo-D1a, low yellow pigment content gene Psy-B1b, soft to medium hardness gene Pinb-D1a, PHS resistant gene Vp-1Bc, non-1B/1R translocation and Wx-B1 null type, and had the least of refered negative genes such as high PPO activity gene Ppo-A1a and high yellow pigment content gene Psy-A1a. 【Conclusion】Australian Standard White was a commercial wheat composed of several cultivars. Pyramiding most of positive noodle quality genes in cultivars and mixing the cultivars in the end-use quality needed proportion resulted in its high noodle quality. For a noodle wheat breeding plan, genotype 2 might be the most promising candidate of noodle quality donors in Australian Standard White.
    Breeding Potentiality of the Inbred Lines Derived From the Maize Populations Developed by Different Cycles of Recurrent Selection
    LI Lu-Jiang, CHEN Wen-Sheng, YANG Ke-Cheng, LAN Hai, PAN Guang-Tang, RONG Ting-Zhao
    Scientia Agricultura Sinica. 2012, 45(18):  3688-3698.  doi:10.3864/j.issn.0578-1752.2012.18.002
    Abstract ( 583 )   PDF (552KB) ( 509 )   Save
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    【Objective】The objective of the present study is to estimate the breeding potentiality of 18 lines derived from six improved populations, thus to provide a scientific basis for generating strategies of deriving lines from an improved population.【Method】A total of 18 inbred lines derived from 6 maize populations developed by different cycles of recurrent selection were used as experiment materials. The phenotypes of the 18 lines per se were analyzed, and the combing ability of major traits was tested according to an incomplete diallel model, the genetic diversity of the lines was analyzed by SSR markers. 【Result】 The results showed that the inbred lines derived from different populations, and the inbred lines derived from different basic individuals in a same population varied in the phenotype and combing ability. The inbred lines P4MSC2-1, P4MSC2-2, P5MSC2-2 and P5MSC2-3 derived from the improved population were superior in yield, yield component and their general combing ability (GCA), the hybrids between these lines and the testers were high in yield. In summary, most of the inbred lines derived from the improved population were better than the inbred lines derived from the base population in yield, yield component and their GCA. However, the inbred lines derived from the improved population were taller in plant height and ear height. The number and percentage of homozygote of the lines derived from the improved populations were roughly equivalent to that of the lines derived from the basic populations with one inbred generation less. The genetic diversity of the lines derived from the improved population showed a decrease trend, but the genetic diversity was still rich relatively. 【Conclusion】All the results indicated that the inbred lines derived from an improved population were more superior, and when the individuals of the improved populations were inbred to develop lines, it became homozygous faster than the basic populations.
    Construction of Methylation Linkage Groups A and B in Sorghum with MSAP and SSR Markers and Analysis of Methylation Sites and Patterns
    DUAN Yong-Hong, WANG Ming, SUN Yi, YANG Wu-De
    Scientia Agricultura Sinica. 2012, 45(18):  3699-3708.  doi:10.3864/j.issn.0578-1752.2012.18.003
    Abstract ( 672 )   PDF (1006KB) ( 661 )   Save
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    【Objective】 The genetic linkage groups of A and B with methylation sensitive markers of Sorghum bicolor L. were constructed, and the methylation sites and methylation patterns were analyzed. 【Method】 F2 segregating population with 150 individuals derived from the sorghum cross B2V4 ×1383-2 was analyzed based on MSAP and SSR markers, and linkage groups were constructed using Map maker/EXP (version 3.0) and Map/Draw 2.1. 【Result】 Methylation linkage groups were constructed. Group A was composed of 30 loci covering 93.7 cM, of which 20 loci were MSAP markers, including 13 loci from EcoRⅠ/MspⅠ enzyme digestion, 7 loci from EcoRⅠ/HpaⅡenzyme digestion, and 10 loci were SSR markers. Group B was composed of 43 loci covering 90.4 cM, of which 39 loci were MSAP markers, including 19 loci from EcoRⅠ/MspⅠenzyme digestion, 20 loci from EcoRⅠ/HpaⅡenzyme digestion and 4 loci were SSR markers. There were only methylation marker products existed from EcoRⅠ/MspⅠ enzyme digestion on linkage group A-a, but on other linkage groups, the methylation markers from both EcoRⅠ/HpaⅡ and EcoRⅠ/MspⅠenzyme digestion were found. Additionally, Group A-b and Group B-b each had a slightly dense methylation resign, nearby Xtxp302 and Xtxp304, while, a highly dense methylation regions, nearby Xtxp 296 in linkage group B-a, with clusters of the EcoRⅠ/Msp I and EcoRⅠ/HpaⅡenzyme digestion MSAP markers were revealed. Based on polymorphism of methylation fragments between parents and their segregation among the F2 population, cytosine methylation patterns between hybrid and their parents were divided into two major groups. 【Conclusion】 MSAP markers can detect a large number of different methylated fragment, with anchor SSR markers, it is an efficient technique in constructing methylation genetic linkage groups or methylation genetic linkage map. High-density methylation regions were revealed near SSR markers Xtxp 302 on Group A-b, Xtxp 96 on Group B-a and Xtxp 304 on Group B-b. Among these loci the number of demethylated loci was higher than the number of methylated loci in hybrid F1 compared to its parents,which might imply a decreased methylation level in the hybrid genome.
    TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY·AGRICULTURE INFORMATION TECHNOLOGY
    A Dynamic Model of Dry Matter and Nutrient Accumulation in Super Hybrid Rice and Analysis of Its Characteristics
    JI Hong-Ting, FENG Yue-Hua, HE Teng-Bing, PAN Jian, FAN Le-Le, LI Yun, WU Biao, XIAO Ming, LIANG Xian-Lin
    Scientia Agricultura Sinica. 2012, 45(18):  3709-3720.  doi:10.3864/j.issn.0578-1752.2012.18.004
    Abstract ( 680 )   PDF (510KB) ( 807 )   Save
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    【Objective】 Modeling dynamics of dry matter and nutrient accumulation of super hybrid rice is an important task for further improvement of yield and rational application of fertilizer.【Method】A field experiment with two super hybrid cultivars (Zhunliangyou527, Qyou 6) and CK(Ⅱyou838) was conducted in 2011, and dry matter accumulation (DMA) and nitrogen, phosphorus and potassium accumulation(NA, PA, KA)were measured. The dynamic equations of relative dry matter accumulation (DMAR) and nitrogen, phosphorus and potassium accumulation (NAR, PAR, KAR) were established with the normalized DMA, normalized NA, PK and KA and normalized growth time, and the dynamic characteristics of DMA and NA, PA, KA changes were analyzed based on the relative equations.【Result】Gompertz simulated better than the other equations for the DMA and nutrient dynamic accumulation characteristics of super hybrid rice. The equations were validated with field experimental data of 2009 and 2011.The NRMSE of DMA simulation were relatively smaller, and R2 values were above 0.9820. The accuracies were about 1, and the NS values were above 0.9530. Validation for the nutrient accumulation equation showed that the model simulated well. The R2, k and NS were all about 1. The analysis of growth characteristics of super hybrid rice showed that the rate of DMA in super hybrid rice was slightly higher than CK at earlier stage and significantly at last stage. The maximum rate of DMA of super hybrid rice was from boot stage to heading stage. The initial of DMA rapid growth stage for super hybrid rice were lower than the CK. The duration of rapid growth period of DMA of super hybrid rice was 71-75 d, which was 16-19 d longer than the CK and the ratio of DMA of rapid growth period in total DMA of super hybrid rice was 4.47%-11.25% higher than that of the CK. The maximum NA rate of super hybrid rice was in 10 d before boot stage. The NA (nitrogen accumulation) rapid growth stage was from 12 d before jointing stage to heading stage, and the NA in rapid growth period was 65.60% of total NA. The maximum PA rate of super hybrid rice was in 8 d before boot stage. The PA(phosphorus accumulation)rapid growth stage was from after jointing stage to 7 d before heading stage, and the PA in rapid growth period was 68.36% of total PA. The maximum KA rate of super hybrid rice was in 3-4 d after jointing stage. The PA(potassium accumulation) rapid growth stage was from 12-16 d after jointing stage to 1-5 d before heading stage, and the KA in rapid growth period was 60.10%-61.71% of total KA. 【Conclusion】The study used the Gompertz equation to simulate the DMA and nutrient dynamic accumulation characteristics of super hybrid rice. The advantage of DMA and nutrient of super hybrid rice were that the duration of rapid growth was longer than that of conventional rice, and the accumulation rate at last stage was faster relatively.
    Long-Lasting Effect of Year-Round Tillage Patterns on Yield and Grain Quality of Wheat in Chengdu Plain of China
    TANG Yong-Lu, LI Chao-Su, WU Chun, MA Xiao-Ling, HUANG Gang
    Scientia Agricultura Sinica. 2012, 45(18):  3721-3732.  doi:10.3864/j.issn.0578-1752.2012.18.005
    Abstract ( 586 )   PDF (425KB) ( 631 )   Save
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    【Objective】 In order to optimize regional farming system, the long-lasting effect of year-round tillage patterns on wheat yield and quality traits was studied. 【Method】 A long-term field experiment under rice-wheat system was established at Guanghan county in Chengdu Plain of China in 2004 to investigate the long-lasting effect of year-round tillage patterns combing tillage and crop straw management on grain yield and quality of wheat. Treatments designed include no-tillage wheat with rice straw mulching + rotary-tillage rice with no wheat straw (WZRR), no-tillage wheat with rice straw mulching + rotary-tillage rice with no wheat straw + Autumn vegetable (WZRRV), no-tillage wheat with rice straw mulching + no-tillage rice with wheat straw mulching (WZRZ), no-tillage wheat with rice straw mulching + no-tillage rice with wheat straw mulching under raised-bed planting (WRZB), and rotary-tillage wheat + rotary-tillage rice without any straw (CK). 【Result】 The results from 7-year duration showed: Undulating changes amongst years in grain yield and yield components for all treatments were observed while CK had lower yields in most years than other treatments with obvious decreasing trend. Obvious descending trend in grain number per spike and upswing in thousand-grain weight for all treatments were observed. All treatments excluding CK improved available N, P, and K content of up layer soil at major stages of wheat growth and the quality of individual plant and canopy at late stage. Most grain quality traits of wheat of WZRZ and WRZB were slightly higher than or same as that of CK but WZRR and WZRRV showed a downward trend in grain protein content, Zeleny sedimentation volume, and dough stability time.【Conclusion】 No tillage, crop straw retention and their year-round combinations could stable grain yield of wheat and improve soil fertility, with highlights in technological packages of both no tillage and straw retention for wheat and rice.
    Evaluation of Mixed Salt-Tolerance at Germination Stage and Seedling Stage and the Related Physiological Characteristics of Panicum miliaceum L.
    LIU Min-Xuan, ZHANG Zong-Wen, WU Bin, LU Ping
    Scientia Agricultura Sinica. 2012, 45(18):  3733-3743.  doi:10.3864/j.issn.0578-1752.2012.18.006
    Abstract ( 760 )   PDF (395KB) ( 1039 )   Save
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    【Objective】 Salt-tolerance and physiological responses of broomcorn millet (Panicum miliaceum L.) were evaluated under a range of NaCl+Na2SO4 concentrations to explore and utilize the germplasm with high salt-tolerance and to provide physiological indicators for identifying salt-tolerance at seedling stage. 【Method】 The growth parameters of 16 genotypes of P. miliaceum L. at germination and seedling stages were measured under various salt stresses, and the genotypes were sorted out using the method of membership function. The physiological characteristics of the genotypes in terms of concentration of proline and Na+/K+ were analyzed.【Result】It was shown that the relative germination value, survival seedling number, shoot length, root length and biomass of above and underground all decreased with the increase of salt concentration, although genotypes differed in the degrees of response to salt stress. Based on the membership function on the means of parameters at germination and seedling stages for each level of salt stress, the 16 genotypes were finally ranked with Zhongwei Dahuangmi, Ningmi No4 and 64-4129 as the most tolerant genotypes, and Bameng 573 Huangmizi, Yimen Yidianzong and Wahui Ruanmi as the least tolerant ones among all tested materials. Proline content in shoot increased in response to increased salt stress, with Zhongwei Dahuangmi and Ningmi No.4 had significantly higher proline content, while lower relative Na+/K+ than the others when salt concentrations at 160 and 200 mmol.L-1 (P<0.05). 【Conclusion】Remarkable variations in salt tolerance were detected among the 16 genotypes of P. miliaceum L., which have provided a basis for the utilization of salt tolerant broomcorn millet genetic resources.
    PLANT PROTECTION
    Isolation, Screening and Identification of Bacterial Agents for Biological Control of Colorado Potato Beetle (Leptinotarsa decemlineata)
    LUO Hua-Dong, YAN Jia-Lin, YU Yang, TAN Wan-Zhong
    Scientia Agricultura Sinica. 2012, 45(18):  3744-3754.  doi:10.3864/j.issn.0578-1752.2012.18.007
    Abstract ( 662 )   PDF (473KB) ( 640 )   Save
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    【Objective】 The objective of this study is to isolate and screen bacterial biocontrol agents against Colorado potato beetle (CPB) (Leptinotarsa decemlineata). 【Method】 Diseased CPB adult samples were collected from Xinjiang and bacterial isolates were obtained from the samples. These isolates were tested for CPB pathogenicity. Highly insecticidal isolates were screened through laboratory and field assays and identified morphologically and molecularly. 【Result】 A total of 126 bacterial isolates were obtained from diseased adults of CPBs collected from Xinjiang Autonomous Region of China and 36 isolates showed protein- and chitin-degrading activity. Among these isolates, 11 infected 1st instar and 2nd instar CPB larvae and resulted in lethal rates of 21.0%-77.9% within 7 days after inoculation when tested on detached potato leaves in the laboratory. The 11 infectious isolates were selected for field tests and 6 of them induced high CPB mortality rates. The CPB-lethal rates by the 3 isolates (CPB008, CPB012 and CPB016) reached 41.0%-49.9%. The other 3 isolates (CPB072, CPB108 and CPB111) also had significantly high CPB lethal rates (21.1%-37.8%). CPB008, CPB012, CPB016 and CPB111 were identified as Bacillus thuringiensis and CPB072, CPB108 were B. atrophaeus, respectively. 【Conclusion】 The screened 3 isolates (CPB008, CPB012 and CPB016) have strong CPB pathogenicity, and could be potential applications in biological control of this destructive pest in Xinjiang of China.
    Cloning, Expression and Activity Analysis of Carboxylesterase Gene from Aphis glycines (Hemiptera: Aphididae)
    YANG Shuai, WANG Ling, ZHAO Kui-Jun, HAN Lan-Lan
    Scientia Agricultura Sinica. 2012, 45(18):  3755-3763.  doi:10.3864/j.issn.0578-1752.2012.18.008
    Abstract ( 636 )   PDF (501KB) ( 665 )   Save
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    【Objective】 The objective of this study is to clone carboxylesterase gene and provide a molecular basis for insecticide resistance of Aphis glycines. 【Method】 A full-length cDNA was cloned by using reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) methods, and the carboxylesterase gene was named AgCarE, and inserted into Escherichia coli. The carboxylesterase activity of AgCarE was characterized with the α-NA as a substrate and its enzyme activity was analyzed. 【Result】 The AgCarE is 1 946 bp in length, and the open reading frame encodes 526 amino acids (GenBank accession number is JF970181). The predicted isoelectric point of AgCarE is 6.08. The AgCarE possesses a catalytic triad, consisting of a Ser, a His and a Glu residue (Ser186, Glu313 and His434), which is characterized by carboxylic esters (EC: 3.1.1.-). The AgCarE was recombined into pET21b vector. Then the HIS fusion protein was expressed by induction with IPTG. The result of SDS-PAGE and Western-blot analysis showed that the AgCarE protein from A. glycines was expressed in E. coli BL21 which induced by IPTG, and its MW was found to be about 59 kD, similar as the predicted result. The activity for AgCarE is 0.036 mmol/100 μL enzyme buffer. 【Conclusion】 A cDNA encoding carboxylesterase from A. glycines was cloned and expressed. The results will further explore the three-dimensional structure, hydrolysis of carboxylesterase and provide a possibility for the design of new types of pesticides.
    The Antifungal Activity and Action Mechanism of Metabolite Produced by Streptomyces lydicus Strain A01 Against Fusarium oxysporum f. sp. conglutinans
    LU Cai-Ge, LIU Wei-Cheng-?, LIU Ting, DONG Dan, ZHANG Tao-Tao, LIU De-Wen
    Scientia Agricultura Sinica. 2012, 45(18):  3764-3772.  doi:10.3864/j.issn.0578-1752.2012.18.009
    Abstract ( 708 )   PDF (1127KB) ( 1000 )   Save
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    【Objective】The objective of this study is to understand the antifungal activity and action mechanism of natamycin produced by Streptomyces lydicus strain A01 against Fusarium oxysporum f. sp. conglutinans, and to provide a scientific basis for product development and application of strain A01.【Method】Mycelial radial growth assay and microscope concave slide method were used to test suppression of mycelia growth and inhibition of spore germination. Electrical conductivity method and methylene blue stain were used to test permeability of pathogen plasma membrane and cell viability of this pathogen. SEM and TEM observations were used to observe morphology and ultrastructure of mycelia.【Result】The MICs of natamycin against the mycelia growth and the conidial germination of F. oxysporum f. sp. conglutinans were less than or equal to 31.92 and 41.04 μg•mL-1, respectively, and the IC50 and EC50 were 8.69 and 3.06 μg•mL-1, respectively. After being treated by natamycin at concentration above 30 μg•mL-1 for more than 90 min, the electrical conductivity of the mycelial suspension was significantly increased. The action intensity was correlated positively with natamycin concentration and the action time. The changes in morphology and cell ultrastructure of the treated mycelia were observed under SEM and TEM, such as abnormal growth or malformation, disintegration of organelles, cell vacuolization and so on. The mycelia treated with natamycin over 10 μg•mL-1 for 120 min could be stained with methylene blue.【Conclusion】The active metabolite of strain A01, natamycin, has obvious inhibitory activities against F. oxysporum f. sp. conglutinans. The bioactivity was based on that natamycin could increase the permeability of plasma membrane, destroy the mycelial morphology and cell ultrastructure, thus resulted in the disappearance of cell viability of the pathogen mycelium.
    SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT
    Comparison of Soil Organic Carbon, Microbial Diversity and Enzyme Activity of Wetlands and Rice Paddies in Jingjiang Area of Hubei, China
    JIN Zhen-Jiang, TAI Ji-Cheng, PAN Gen-Xing, LI Lian-Qing, SONG Xiang-Yun, XIE Tian, LIU Xiao-Yu, WANG Dan
    Scientia Agricultura Sinica. 2012, 45(18):  3773-3781.  doi:10.3864/j.issn.0578-1752.2012.18.010
    Abstract ( 682 )   PDF (768KB) ( 1385 )   Save
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    【Objective】The purpose of this study is to, by means of a comparative analysis of soil organic carbon (SOC), microbial community abundance and soil enzyme activity, look into the relationship between SOC and microbial abundance/activity after rice cultivation of wetland soil for several decades. 【Method】 The topsoil (0-20 cm) samples of uncultivated wetland and paddy field were collected in Jingjiang area, Hubei, China. Contents of SOC, soil microbial biomass carbon (SMB-C) and microbial community abundance were analyzed using wet digestion with potassium dichromate, chloroform fumigation-extraction, dilute plate incubation counting and PCR-DGGE assays respectively. Microbial activity was examed using soil enzyme assays as well. 【Result】 The results showed that the SOC content increased by 55.42%, in accordance to the increases of total N and alkali-hydrolyzable N in rice paddies compared to wetland. SMB-C was found 180% higher in rice paddies than in wetlands. There was no significant difference in abundance of a single microbial community of bacterial, fungi, actionmycetes and autotrophic azotobacter, neither in diversity of bacterial and fungi between wetlands and rice paddies. However, microbial enzyme activities of invertase, urease and alkaline phosphatase was enhanced by 89%, 70% and 72%, respectively, in rice paddy over wetlands. Statistical analysis revealed a significant correlation of SMB-C and normalized overall enzyme activity index with soil organic carbon contents, respectively. 【Conclusion】 These results indicate that the size of soil microbial biomass and microbial functional activity with enzymes were enhanced as SOC storage increased due to rice cultivation of wetlands for several decades. Therefore, SMB-C size and normalized enzyme activity could be used as indicators for soil functioning by SOC.
    Effects of Mixed Application of Controlled-release Fertilizer and Common Fertilizers on Greenhouse Tomato Growth, Yield, Root Distribution, and Soil Nitrate Residual
    YANG Jun-Gang, ZHANG Dong-Lei, XU Kai, NI Xiao-Hui, XIAO Qiang, CAO Bing, LIU Bao-Cun, ZOU Guo-Yuan
    Scientia Agricultura Sinica. 2012, 45(18):  3782-3791.  doi:10.3864/j.issn.0578-1752.2012.18.011
    Abstract ( 652 )   PDF (419KB) ( 1338 )   Save
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    【Objective】An experiment was conducted in greenhouse in a Beijing suburb to evaluate the effects of mixed application of controlled-release fertilizer (CRF) and common fertilizers on tomato growth and its environmental pollution. 【Method】Plant height,diameter, leaf area and chlorophyll, root distribution, fresh fruit yield and quality, mineral N (Nmin) dynamics in the 0 to 30 cm soil layer and NO3--N residual at harvest in the 0-180 cm soil profile were investigated. 【Result】The results showed that fruit yields were 84.1-90.8 t•hm-2 and there was no significant difference among treatments. However, in the controlled-release fertilizer treatment (CN270), fruit nitrate concentration was decreased and the sugar or acid content was improved when compared with other treatments. Plant height and diameter, or leaf chlorophyll were not reduced and leaf area was enlarged and then reached a remarkable difference level at the third spike fruit expanding stage in the CN270 treatment, when compared with the conventional fertilizer treatment (N450) which received 40% more nitrogen than the CN270 treatment. Most of the root system was concentrated in the top 30 cm of the soil profile, where root length density ranged between 0.39 and 1.75 cm•cm-3. Values of root length density from the N450 and CN270 treatments were similar, but were obviously larger than that from another conventional fertilizer treatment which received 270 kgN•hm-2(N270). Nmin ranged from 643 to 796 kg•hm-2 in the CN270 treatment in the 0-30 cm soil layer at fruit expanding stage, and a better N supply to meet plant requirement was also observed. At harvest, most of NO3--N accumulation in the surface soil layer in CN270 treatment resulted in less nitrate leaching down to the deeper soil layer. 【Conclusion】It was be concluded that the application of CRF and common fertilizers at a lower N rate achieved the same yield and higher fruit quality, better root growth and less leaching of NO3--N to deeper soil layers, when compared to conventional fertilization at a higher or same N rate. The mixed application of CRF and common fertilizer on the greenhouse tomato is a better way to obtain a better-quality fruit and energy-saving production system.
    Construction of cDNA Library of Penicillium oxalicum I1 and Screening of Phosphate-Dissolving Related Gene
    TANG Chao-Xi, GONG Ming-Bo, LI Shun-Peng, ZHU Chang-Xiong
    Scientia Agricultura Sinica. 2012, 45(18):  3792-3800.  doi:10.3864/j.issn.0578-1752.2012.18.012
    Abstract ( 589 )   PDF (600KB) ( 586 )   Save
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    【Objective】The objective of this study is to obtain phosphate-dissolving related genes from cDNA library of Penicillium oxalicum I1. 【Method】 A primary cDNA library of P. oxalicum I1 was constructed using SMART (switching mechanism at 5′ end of RNA transcript) technique. Transformants with phosphate-dissolving activities were screened on the insoluble phosphate medium, and the sequence of the bioinformation was analysed. To study the phosphate-dissolving mechanisms of the cloned gene, the changes of the pH value, the soluble phosphate content and the production of organic acids were analyzed in the insoluble phosphate liquid medium inoculated with the transformants harboring the phosphate-dissolving gene. 【Result】A cDNA library of P. oxalicum I1 was successfully constructed. Titer tests showed that the content of constructed P. oxalicum I1 cDNA library reached 5.29×106 cfu•mL-1, in which the percentage of recombinants was 99%. Forty-eight transformants with phosphate-dissolving activities were screened on the solid medium with insoluble phosphate. The corresponding gene in one of these transformants was identified. The full length cDNA of transformant I-4 was 536 bp, encoding a predicted protein with 129 amino acid residues. The expression of phosphate-dissolving gene in E. coli could enhance organic acids secretion and improve the phosphate solubilizing activity. It was found that acetic acid was secreted in 12 h, and lactic acid, malic acid and α-ketoglutarate were secreted in 24 h. The transformant I-4 decreased the pH value of medium from 6.32 to 3.69 and released soluble phosphate up to 0.1076 mg•mL-1 in 36 h. 【Conclusion】A phosphate-dissolving related gene, designated pstI, was screened from the cDNA library of P. oxalicum I1.
    HORTICULTURE
    Differences in Tolerance of Four Apple Rootstock Seedlings to Zinc Stress
    LIU Fei, WANG Jin-Hua, ZHANG Hong-Yi, FU Chun-Xia, WANG Yan-An
    Scientia Agricultura Sinica. 2012, 45(18):  3801-3811.  doi:10.3864/j.issn.0578-1752.2012.18.013
    Abstract ( 809 )   PDF (349KB) ( 886 )   Save
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    【Objective】The response difference of four apple rootstock seedlings under variable zinc concentrations were investigated. The purpose of this work is to compare the tolerance of four apple cultivars to low and high zinc stress, which also has important significance in screening apple rootstocks well adapted to zinc stress. 【Method】The experiment was carried out with the seedlings of four apple rootstocks cultivars grown hydroponically under different zinc concentrations. The growth, dry weight, the morphology and architecture of root ,root activity, zinc accumulation and  utilization efficiency of apple rootstock seedlings were measured and analysised.【Result】The changes in height, biomass of plant, morphology and architecture of root, root activity, zinc accumulation and utilization in plant were studied under zinc deficiency (0 μmol•L-1), low zinc (1 μmol•L-1), control (4 μmol•L-1), optimal zinc (10 μmol•L-1), and excess zinc (100 μmol•L-1) with hydroponics. Results showed that many obvious zinc-deficiency symptoms were observed in the three apple rootstock (Malus hupehensis Rehd., M. xiaojinensis Cheng et Jiang., M. robusta Rehd.) seedlings receiving no Zn supply for 45 d, such as, the plant dwarfed, the new smaller leaves and the length of stem node decreased. The four apple rootstock seedlings all showed toxic symptoms receiving excess Zn, such as, the plant dwarfed, the new leaves etiolated and growth inhibited. The biomass, the height, total length, total surface of root, significantly decreased and the decreased degree was M. baccata Borkh. >M. hupehensis Rehd. >M. robusta Rehd. >M. xiaojinensis Cheng et Jiang. under the low zinc, while M. xiaojinensis Cheng et Jiang. performed more higher than that of other rootstock seedlings. And these physiological and morphological responses of root to excess zinc were exhibited: M. robusta Rehd>M. xiaojinensis Cheng et Jiang>M. hupehensis Rehd.>M. baccata. Borkh. Most zinc entered the seedlings were transported up to the part above the ground to meet demand for zinc under the low zinc condition. The toxicity of zinc to shoot was weakened though to retain most zinc in root under excess zinc condition.【Conclusion】The tolerance to deficient zinc of M. xiaojinensis Cheng et Jiang was higher than that of others, M. baccata Borkh. was sensitive to Zn-deficiency. The tolerance to excess zinc of M. robusta Rehd. was higher than that of others. The root tolerance to excess zinc of M. baccata Borkh. was weaker than that of others.
    Genetic Presentation of BC1 Between ‘Zhongshanjingui’ and ‘Zhongshanjingui’ × Ajania przewalskii
    ZHU Wen-Ying, LIU Xin-Chun, FANG Wei-Min, GUAN Zhi-Yong, CHEN Su-Mei, JIANG Jia-Fu, CHEN Fa-Di
    Scientia Agricultura Sinica. 2012, 45(18):  3812-3819.  doi:10.3864/j.issn.0578-1752.2012.18.014
    Abstract ( 650 )   PDF (1039KB) ( 527 )   Save
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    【Objective】Genetic presentation of BC1 between ‘Zhongshanjingui’ and ‘Zhongshanjingui’×Ajania przewalskii. was studied in order to obtain new germplasm with higher ornamental and cold tolerance.【Method】Backcross hybridizations were made between Dendranthema morifolium variety ‘Zhongshanjingui’ (as female) and ‘Zhongshanjingui’×Ajania przewalskii (as male). The backcross hybrids were obtained and their hybridity was confirmed by a combination of morphological, cytological analysis and resistance comparison.【Result】A total of 17 backcross hybrids were obtained. The hybrids differentiated obviously from their parents in many morphological characters and all hybrid lines bloomed normally. There happened three flower types, i.e. standard anemone type, mid-anemone type and non-anemone type, and most were anemone type. Some hybeids’ inflorescence diameter was greater than ‘Zhongshanjingui’, the flower color was the same as ‘Zhongshanjingui’. Compared with the male parent, the ornamental value was greatly improved. The chromosome number of ‘Zhongshanjingui’ and ‘Zhongshanjingui’×Ajania przewalskii were 54 and 45, respectively. Their backcross hybrids chromosome number was between 41-54. In comparison of cold resistance, almost all the hybrids showed higher tolerance than ‘Zhongshanjingui’, which illustrated the backcross hybrids preserved the cold tolerance of Ajania przewalskii. 【Conclusion】By using backcross between intergeneric hybrid F1 and its chrysanthemum parent, not only the intergeneric hybrid’s ornamental vatue can be improved, but new germplasm of chrysanthemum also can be created.
    STORAGE·FRESH-KEEPING·PROCESSING
    Effect of De-Fat and De-Protein Treatments on Swelling Power of Chinese Chestnut (C. mollissima Bl.) Powder
    LIANG Li-Song, LIN Shun-Shun, ZHANG Bai-Lin, WANG Gui-Xi
    Scientia Agricultura Sinica. 2012, 45(18):  3820-3831.  doi:10.3864/j.issn.0578-1752.2012.18.015
    Abstract ( 734 )   PDF (407KB) ( 560 )   Save
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    【Objective】 The experiments were conducted to compare the swelling power of chestnut native powder of 24 cultivars of Chinese chestnut (Castanea mollissima Blume) from different cultivar groups, and investigate the effect of de-fat and/or de-protein on swelling power of different cultivars of Chinese chestnut power.【Method】The contents of protein, fat and starch were determined by Kjeldahl method, Soxhlet extraction method and Anthracene ketone colorimetric method, respectively. The native power, de-fat power and de-protein power of chestnut were obtained by freeze-drying, SoxhLet extraction and alkali liquor precipitation, respectively. Statistical analysis was performed using SPSS version 11.0. 【Result】 Differences of swelling power of chestnut native powder were found among different cultivars and different cultivar groups. Native powder of chestnut from North Cultivar Groups (NCG) had the lowest swelling power compared with other two cultivar groups. De-fat treatment had less influence on swelling power of chestnut powder. However, de-protein treatment increased significantly the swelling power of all cultivars chestnut. There were obvious differences in swelling power and the changes of swelling among cultivars after de-protein, but no differences among different cultivar groups were found. The combination of de-fat and de-protein resulted in significant increases in swelling power and there existed differences among the cultivars. The swelling power of de-protein powder of chestnut followed the sequence: North Cultivar Groups (NCG) > Mid-type Cultivar Groups (MCG) > South Cultivar Groups (SCG). There was a significant difference between NCG and SVG. The differences of content of starch, protein and fat occurred in different cultivar chestnuts, and apparent correlation between starch content and swelling power of chestnut powder were conformed in the meanwhile.【Conclusion】Starch was the main factor influencing swelling power of chestnut powder. Protein and fat in chestnut coordinately influence the swelling power of chestnut powder, which can be modified by de-fat and de-protein treatments. De-protein treatment can remarkably enhance the swelling power while less influence can by caused be de-fat treatment. The effects resulted from de-fat and de-protein were dependent on the cultivars or cultivar groups.
    Effect of Different Preservatives on Post-Harvest Physiological and Storage Quality in Ginkgo biloba Seeds
    WU Cai-E, LI Ting-Ting, FAN Gong-Jian, CHEN Rong, WU Hai-Xia
    Scientia Agricultura Sinica. 2012, 45(18):  3832-3840.  doi:10.3864/j.issn.0578-1752.2012.18.016
    Abstract ( 556 )   PDF (459KB) ( 651 )   Save
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    【Objective】 The effects of different preservatives on post-harvest physiological and storage quality in Ginkgo biloba seeds were studied for the purpose to find a way to prolong the storage life of Ginkgo seeds. 【Method】 Ginkgo biloba seeds called“Buddha” were treated with different preservatives(sodium dichloroisocyanurate, ClO2 tablets, grape preservative tablets and thiabendazole ), and the changes rule about the physiology and biochemistry and the storage quality during storage under 4℃ were studied.【Result】The respiratory intensity of Ginkgo biloba seeds was inhibited and the increase of MDA content was suppressed by thiabendazole and low membrane permeability was maintained. The activities of POD and CAT were maintained at higher levels at the end of storage by thiabendazole, and they were 1970.3 U•g-1 and 826.2 U•g-1, respectively. The generation of reducing sugar and soluble sugar were postponed by thiabendazole ,and the starch content was maintained at higher levels which was 21.39% at the end of storage.The water content of Ginkgo biloba seeds soaked in thiabendazole solution was increased. The propagation of pathogens could be inhibited by thiabendazole and could keep good fruit rate higher.【Conclusion】Ginkgo biloba seeds treated with thiabendazole can keep better storage quality and longer storage life and the storage effect is better than other preservatives.
    ANIMAL SCIENCE·RESOURCE INSECT
    Effects of S-Adenosylmethionine (SAM) on Adipogenic Differentiation and Lipid Accumulation of C2C12 Cells
    YU Bo-Yang, 吕Wen-Tao , JU Ting-Ting, LIU Yang, JIANG Mei-Hua, YIN Jing-Dong
    Scientia Agricultura Sinica. 2012, 45(18):  3841-3848.  doi:10.3864/j.issn.0578-1752.2012.18.017
    Abstract ( 679 )   PDF (429KB) ( 685 )   Save
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    【Objective】This experiment was conducted to investigate the effects of S-adenosylmethionine (SAM) on adipogenesis and lipogenesis of C2C12 mouse myoblast. 【Method】Cells were cultured in high glucose DMEM medium containing 0 mmol•L-1, 0.25 mmol•L-1, 1.0 mmol•L-1, and 2.0 mmol•L-1 SAM. After treated for 0 h, 24 h, 36 h, and 48 h, cells were stained with Red Oil O and observed under microscope. The lipid accumulation in cytosol was determined by optical density (OD) measurement. After being treated for 2 d, cells were harvested for collection of total RNA and protein. Then RT-PCR and western blotting approaches were used to determine mRNA and protein expression levels of several genes related with adipogenesis and lipogenesis. 【Result】The results showed that, compared with the control group, C2C12 cells presented typical features of adipocytes when observed under microscope after treated with SAM. SAM also increased the number of lipid droplets in the cells. In addition, the increasing trend became more significant when cells were treated with higher concentration of SAM. At the same time, mRNA and protein expression levels of key regulator of differentiation of adipocytes, PPARγ and C/EBPα, were elevated (P<0.05) after treatment. mRNA expression levels of other lipogenesis related genes, such as aP2, FAS and SREBP-1, were also elevated markedly. Compared with the control group, the relative mRNA levels of these three genes were increased by 6.86 (P<0.01), 3.45 (P<0.05), and 3.48 (P<0.01) folds, respectively, in 2.0 mmol•L-1 group. 【Conclusion】The results indicated that SAM had the ability to promote adipogenic differentiation and lipid accumulation of C2C12 cells.
    Simulation of Genetic Diversity Variation in Domestic Animal Population Under Conservation
    LU Yun-Feng, WANG Qian, HUANG Wen-Bo, SHI Li-Hua, WU Ke-Liang
    Scientia Agricultura Sinica. 2012, 45(18):  3849-3858.  doi:10.3864/j.issn.0578-1752.2012.18.018
    Abstract ( 744 )   PDF (383KB) ( 1002 )   Save
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    【Objective】The changes of genetic diversity of domestic animals’ genetic resources were studied by using computer simulation based on the characteristics of microsatellite markers.【Method】Thirty mark loci were chosen and they are equally distributed in the whole genome, and each locus has 4-10 alleles, no interactions between these loci. Computer simulation was based on the assumption that there was no gene mutation, selection ratio of male and female is 1﹕5 and random mating was implemented in all generations, the generation was non-overlapping and the number of breeding animals was selected through mating by family in equality, effective population size (Ne) were 10, 20, 50, 100 and 200. The simulation experiment was carried out for 50 generations and 1000 repeats. The number of polymorphic loci (Num-p), allele number (Na), number of effective alleles (Ae), observed heterozygosity (Ho), expected heterozygosity (He), number of rare alleles (RA), number of non-rich polymorphic loci (NRP) were indicators as genetic diversity.【Result】The overall trend of genetic diversity of conservation populations was decreased over generations, and differences were significant as Ne changed. It was seen that larger values of Ne, the more slower descent rate of num-p, Na, Ae, Ho, He, and RA compared with the base population, and num-p basically maintained at 30, RA decreased by 0.86% and 2.49 times as Ne were 100 and 200. Moreover larger, the values of Ne, the slower increase rate of NRP. 【Conclusion】 Decreases in effective population size that occur at a closed population level will increase gene drift and reduce genetic diversity within conservation population.
    VETERINARY SCIENCE
    Studies on Synergetic Pathogenicity of Co-infection with Highly Pathogenic PRRSV and PCV2
    FAN Pei-Hu, WEI Yan-Wu, GUO Long-Jun, WU Hong-Li, HUANG Li-Ping, LIU Chang-Ming
    Scientia Agricultura Sinica. 2012, 45(18):  3859-3872.  doi:10.3864/j.issn.0578-1752.2012.18.019
    Abstract ( 709 )   PDF (18990KB) ( 263 )   Save
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    【Objective】 The purpose is to study the synergetic pathogenic effect between highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) and porcine cirovirus type 2 (PCV2), and to clarify the relation of ordinal co-infection and synergetic pathogenicity. 【Method】 Thirty 35-day-old piglets were randomly selected and separated into 6 groups which designated PCV2/HP-PRRSV ordinal co-infection group, HP-PRRSV/PCV2 ordinal co-infection group, HP-PRRSV+PCV2 simultaneous co-infection group, HP-PRRSV infection group, PCV2 infection group and control group, respectively. Clinical symptom and temperature were recorded everyday post-inoculation, meanwhile, weighing body weight and collecting blood samples. Variations of CD3+CD4+CD8-, CD3+CD4-CD8+, γδT, NK, granulocyte and mononuclear cell were determined by flow cytometry. Two kinds of antibodies against HP-PRRSV and PCV2 were quantified by immunoperoxidase monolayer assay (IPMA). Concentrations of IFN-γ, TNF-α, IL-10, IL-2, GM-CSF in serum were determined by ELISA. Pathological changes were observed through making pathological section for different organs. 【Result】 All the findings suggest that the pathogenicity of HP-PRRSV/PCV2 ordinal co-infection is conspicuously more severe than other testing groups. Mortality of this group is 60% surprisingly. Virus load in body is the highest while antibodies level is the lowest. Variation of immunocyte subgroups and cytokines (especially TNF-α) is the most conspicuous. 【Conclusion】 There is a synergetic pathogenicity of co-infection of pigs with HP-PRRSV and PCV2. If HP-PRRSV infecting precedes PCV2, the morbility and mortality will be conspicuously enhanced. This study has provided a scientific proof to control the two viruses.
    Isolation, Characterization and Mechanism of Anti-viral Activity of Duck Avian Beta-defensin 16
    ZHANG Ke-Xin, ZHANG Ming-Yue, XIN Sheng-Nan, HAN Zong-Xi, SHAO Yu-Hao, LIU Sheng-Wang, MA De-Ying
    Scientia Agricultura Sinica. 2012, 45(18):  3873-3882.  doi:10.3864/j.issn.0578-1752.2012.18.020
    Abstract ( 799 )   PDF (433KB) ( 462 )   Save
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    【Objective】The objective of the present study was to clone, express, and characterize the antimicrobial activity of duck avian beta-defensin (AvBD16). AvBD16 and TLR-7 dynamic changes were evaluated in different duck organizations after duck hepatitis virus infection. 【Method】The specific cDNA was obtained by PCR from bone marrow of ducks. The cDNA of duck AvBD16 was cloned into pGEX-6p-1 vector to construct recombinant plasmid, which were transformed into E. coli BL21 and the bacteria were induced with IPTG. Furthermore, the recombinant protein was purified. Peptides were synthesized according to the gene sequence. The antimicrobial activity of both recombinant and synthetic AvBDs was investigated in vitro. In addition, the mRNA expressions of AvBD16 and TLR-7 in tissues after duck hepatitis virus (DHV) infection were examined.【Result】Duck AvBD16 consisted of 155 bp encoding 50 amino acids and shared an amino acid homology (62%) with chicken AvBD3. Both recombinant and synthetic duck AvBD16 showed similar antibacterial activities. In high salt ions conditions, antibacterial activity of duck AvBD16 protein was decreased. In addition, the hemolysis activity of the peptide was extremely low. The duck AvBD16 exhibited significant antiviral activity against DHV in vitro. The mRNA expression of AvBD16 and TLR-7 in most tissues, including immune organs and liver, was upregulated or induced in response to DHV infection at different time points.【Conclusion】The duck AvBD16 gene from duck was successfully cloned, expressed in E. coli, and recombinant and synthetic AvBD16 protein showed antimicrobial activity and has no hemolytic properties. Duck AvBD16 exhibits significant antiviral activity against DHV in vitro. This result suggests that the antiviral activity against DHV of the AvBD16 is partially via a TLR7-dependent mechanism.
    RESEARCH NOTES
    Evolution in Photosynthetic Characteristics of Wheat Cultivars Widely Planted in Shandong Province Since 1950s
    PENG Qin, GUO Qian-Huan, ZHANG Xi-Bin, CHENG Dun-Gong, DAI Shuang, LI Hao-Sheng, ZHAO Shi-Jie, SONG Jian-Min
    Scientia Agricultura Sinica. 2012, 45(18):  3883-3891.  doi:10.3864/j.issn.0578-1752.2012.18.021
    Abstract ( 747 )   PDF (434KB) ( 716 )   Save
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    【Objective】The evolution in photosynthetic characteristics of historical wheat cultivars was investigated in order to understand the main yield-limiting factors and guide future breeding strategies for improving light use efficiency.【Method】Changes in grain yield, harvest index (HI) and photosynthetic parameters of eight landmark wheat cultivars widely planted in Shandong province in different years since 1950s were investigated in the fields. 【Result】 The grain yield and HI showed a significant linear improvement in Shandong province with the cultivars changed, however, the biomass did not increase obviously. The chlorophyll content (Chl a and Chl b), net photosynthetic rate (Pn),stomatal conductance (Gs), carboxylation efficiency (CE),photochemical efficiency (ΦPSⅡ) of photosystem Ⅱ (PSⅡ), and respiratory rate (R) of flag leaves from all historical cultivars reached their maximal values between flowering date and 10 days after anthesis (DAA), then declined gradually, and the reduced rate  of varieties after 1980 was less than the varieties before 1980. The intercellular CO2 concentration (Ci) and the non-photochemical quenching (NPQ) increased persistently after the flag leaves were full expanded. The decrease of Pn was not caused by stomatal factors. The carboxylase activity of ribulose bisphosphate carboxylase oxygenase (Rubisco) was crucial for the earlier reduction of Pn after flowering rather than chlorophyll content, while the chlorophyll degradation, ΦPSⅡ and NPQ played important roles in further reduction at the late duration of grain filling. The photosynthetic characteristics improved with the cultivar evolution derived from both the increase in chlorophyll content, Pn, Gs, CE and ΦPSⅡ and their longer duration, and which may be the physiological basis of the grain yield improvement. However, the respiratory rate also enhanced with the cultivar change and which was disadvantage to yield increase. 【Conclusion】Improved photosynthetic characteristics and lengthened duration played important roles in genetic gain in grain yield of Shandong wheat. The HI of Shandong wheat can be improved further, while it should be independent of plant height reduction. The future breeding for yield increase through improving light use efficiency should take all steps involved in photosynthesis as a whole.
    Cloning and Characteristics Analysis of Chemosensory Protein Gene BtabCSP1 in Bemisia tabaci Q Biotype
    BAI Run-E, LI Jing-Jing, TANG Ya-Fei, XIONG Da-Bin, LI Shuai-Liang, YAN Feng-Ming
    Scientia Agricultura Sinica. 2012, 45(18):  3892-3898.  doi:10.3864/j.issn.0578-1752.2012.18.022
    Abstract ( 615 )   PDF (428KB) ( 607 )   Save
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    【Objective】 The objective of this study is to clone the full length cDNA of the gene encoding chemosensory proteins from Bemisia tabaci Q biotype, and to analyze its expression pattern at different developmental stages.【Method】Based on the amino acid sequence of aphids (Myzus persicae) chemosensory proteins OS-D2a (ABM5558) reported previously, a pair of primers were designed based on simulation of gene splicing and RT-PCR was used to clone the chemosensory protein gene BtabCSP1. 【Result】Sequencing and structural analysis showed that BtabCSP1 contains a 2 626 bp long complete reading frame (with 2 exons and 1 intron) and encodes 131 amino acid residues with a CX6CX18CX2 domain, the typical characteristics of a chemosensory protein gene. As displayed by semi-quantitative RT-PCR amplification from total RNA of B. tabaci of various stages, BtabCSP1 was expressed in all samples and the expressions were more apparent in the 2nd instar, 3rd instar and 4th instar (pupal stage) nymphs. The amino acid (encoded by BtabCSP1) sequence cluster analysis showed that B. tabaci was distantly related to fruit flies and aphids and chemosensory protein gene was active in the process of species evolution.【Conclusion】BtabCSP1 was isolated from B. tabaci Q biotype, and the expression pattern suggested the close relationship between the expression of this gene and the development of B. tabaci.