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Table of Content

    15 November 2012, Volume 45 Issue 22
    CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS
    Relationship Between the Expression of Genes Encoding Resistance-related Enzymes and the Resistance to Sclerotinia sclerotiorum in Resynthesized Brassica napus with High Level of Resistance
    WAN Hua-Fang, LIU , YAO , MEI Jia-Qin, DING Yi-Juan, LIANG , YING , QU Cun-Min, LU , KUN , LI Jia-Na, QIAN , WEI
    Scientia Agricultura Sinica. 2012, 45(22):  4543-4551.  doi:10.3864/j.issn.0578-1752.2012.22.001
    Abstract ( 517 )   PDF (722KB) ( 774 )   Save
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    【Objective】 The relationship between the expression of genes encoding resistance-related enzymes and the resistance to S. sclerotiorum in resynthesized B. napus RB165 with high level of resistance was investigated.【Method】 RB165 was employed to investigate sclerotinia resistance using detached leaf and stem assay and to monitor the expression of genes encoding resistance-related enzymes (oxalate oxidase, Cu/Zn superoxidase dismutase, β-1,3-glucanase and chitinase) after sclerotinia inoculation with qRT-PCR, together with the resistant parental adopter (RP), four natural rapeseed lines with diverse levels of resistance.【Result】The leaf resistance was highly and positively correlated to that of the stem (r = 0.93) among 6 accessions. The resistance of RB165 was lower than that of RP, but significantly higher than that of natural rapeseed. The pattern of gene relative expression detected with qRT-PCR at 0, 6, 12, 24, 36 hours post inoculation (hpi) of S. sclerotiorum significantly differed in leaf, but the dynamics was similar among 6 accessions, i.e. OXO was inhibited, Cu/Zn SOD was inhibited at the beginning of inoculation, and then activated, PR2 was strongly induced twice and PR3 was dramatically activated. 【Conclusion】 RB165 was more resistant to S. sclerotiorum than natural rapeseed. No significant relationship was detected between S. sclerotiorum resistance and the expression of OXO, Cu/Zn SOD, PR2 and PR3.
    Detection of Quantitative Trait Loci for Plant Height in Different Environments Using an RIL Population in Cucumber
    MIAO , HAN , GU Xing-Fang, ZHANG Sheng-Ping, ZHANG Zhong-Hua, HUANG San-Wen, WANG , YE
    Scientia Agricultura Sinica. 2012, 45(22):  4552-4560.  doi:10.3864/j.issn.0578-1752.2012.22.002
    Abstract ( 643 )   PDF (856KB) ( 905 )   Save
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    【Objective】Plant height is related closely to cucumber (Cucumis sativus L.) yield and plant development. QTL analysis for the traits related to plant height in cucumber can provide a basis for fine mapping and gene cloning. The result not only provide a theoretical basis for molecular assistant selection (MAS) breeding in plant morphogenesis and high yield, but also integrate research results of plant height.【Method】Phenotypic data of 148 F9 recombinant inbred lines (RILs) which originated from a narrow-cross between 9110Gt and 9930 were investigated four times in different seasons. Using a SSR linkage map, the multiple QTL model (MQM) method of software package MapQTL version 4.0 was employed to map and analyze QTLs. Based on the whole genome sequence, the genomic regions harboring QTLs related to plant height were analyzed using comparative mapping and BLAST soft. 【Result】 QTL mapping analysis was conducted for three cucumber traits related to plant height, length of the main stem internode, and node number of main stem, in this study. Eleven QTLs were detected for these traits. These QTLs were mapped on chromosomes 1, 2, 5 and 6, respectively. Their LOD values varied between 3.03 and 12.73, which explained 6.2%-32.1% of the phenotypic variation. Five QTLs explained phenotypic variation more than 10%. Three QTLs (27.3% ) were found to be expressed consistently under four cropping seasons in greenhouse cultivation. QTL cluster was detected on Chr.1. 【Conclusion】 Based on the results in this study, it is speculated that there are at least four genes controlling plant height of cucumber, de gene controlling the determinate habit in cucumber was found in the region of QTLs mapped on the long-arm of Chr.6.
    TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY·AGRICULTURE INFORMATION TECHNOLOGY
    Effect of High Temperature and Drought on Grain Yield and Quality of Different Rice Varieties During Heading and Early Grain Filling Periods
    DUAN , HUA , TANG , QI , JU Cheng-Xin, LIU Li-Jun, YANG Jian-Chang
    Scientia Agricultura Sinica. 2012, 45(22):  4561-4573.  doi:10.3864/j.issn.0578-1752.2012.22.003
    Abstract ( 791 )   PDF (742KB) ( 1187 )   Save
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    【Objective】Heading/flowering and early grain filling are the most stress-sensitive periods in rice growth and development. However, little is known about how high temperature and water stress during these periods affect rice yield and grain quality. This study investigated pollen development, yield components, grain quality and some physiological parameters under high temperature and water stress during heading and early grain filling periods.【Method】Two conventional indica rice cultivars, Shuanggui 1 (heat-sensitive) and Huanghuazhan (heat-tolerant), and two super rice cultivars, Liangyoupeijiu (indica-inclined two-line hybrid) and Yangjing 4038 (japonica), were grown in pots and subjected to high temperature treatments (HT, maximum temperature during the day at 37.5℃), soil drying treatments (SD, soil water potential at -30±10 kPa) and high temperature plus soil drying treatments (HT+SD), and the natural temperature plus well-watered treatment was taken as the control (CK).【Result】The results showed that high temperature, soil drying or high temperature plus soil drying treatments significantly reduced pollen fertility rate, fertilization rate, seed-setting rate, grain yield, milled rice, head rice and break down viscosity, increased chalky grains, chalkiness degree and setback viscosity in each cultivars. The effect was more obvious on heat-sensitive than on heat-tolerant cultivars, and more evident on Liangyoupeijiu and Yangjing 4038 than on Shuanggui 1 and Huanghuazhan under both high temperature and high temperature plus soil drying treatments. The result was discrepant under soil drying treatments, the extent of the decrease or increase was more on heat-sensitive than on heat-tolerant cultivars, but more evident on Shuanggui 1 and Huanghuazhan than on Liangyoupeijiu and Yangjing 4038. The effect of high temperature treatments, soil drying treatments or high temperature plus soil drying treatments on yield and grain quality was consistent with that on root activity, net photosynthetic rate of the flag leaf and activities of antioxidative enzymes.【Conclusion】The results suggest that the reduction of grain yield and grain quality under high temperature or soil drying treatments during heading and early grain filling varies largely with rice cultivars. Heat-tolerance is better for Shuanggui 1 and Huanghuazhan than for Liangyoupeijiu and Yangjing 4038, and drought-tolerance is stronger for Liangyoupeijiu and Yangjing 4038 than for Shuanggui 1 and Huanghuazhan. Stronger root activity and antioxidative defense system and greater net photosynthetic rate of the flag leaf would be an important physiological mechanism in maintaining a higher grain yield for a rice variety under high temperature or drought stress.
    Effect of Tillage in Fallow Period on Soil Water, Post-Anthesis Proline Accumulation and Grains Protein Accumulation in Dryland Wheat
    ZHAO Hong-Mei, GAO Zhi-Qiang, SUN Min, ZHAO Wei-Feng, LI Qing, DENG Yan, YANG Zhen-Ping
    Scientia Agricultura Sinica. 2012, 45(22):  4574-4586.  doi:10.3864/j.issn.0578-1752.2012.22.004
    Abstract ( 614 )   PDF (657KB) ( 834 )   Save
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    【Objective】 A field plot experiment was conducted to study the effect of tillage in fallow period at different times on soil water storage, post-anthesis proline accumulation in flag leaves and grains and grains protein accumulation in winter wheat. The study will supply a new way for soil moisture conservation of one time in fallow period and a theoretical basis for improving yield and quality of dryland wheat.【Method】The effects of two treatment stages including 15 days and 45 days after wheat harvest, two tillage methods including deep tillage and subsoiling (no tillage as control) on soil water storage, post-anthesis proline accumulation in flag leaves and grains, protein accumulation, the change of activity of glutamine synthetase (GS) and activity of glutamate dehydrogenase(GDH), grains protein and the relation between proline content and nitrogen metabolism enzyme were determined. 【Result】The results showed that soil water storage at the depth of 0-300 cm was improved by tillage in fallow period, especially in dry year and deep tillage in 45 days after wheat harvest had better soil moisture conservation effects. Proline content in flag leaves, proline content in grains of post-anthesis 5-15 d and activity of GDH in flag leaves and grains were reduced, however, GS in grains and protein yield in grains were enhanced by tillage in fallow period. Tillage stage had obvious difference in activity of GS and grain protein content in different rainfall years. Activity of GS in flag leaves and protein content in grains were reduced by tillage in dry year. In abundant water year the activity of GS in flag leaves and protein content in grains were reduced in 15 days after wheat harvest and enhanced in 45 days after wheat harvest by tillage. Under tillage in fallow period, the correlation between soil water storage before sowing and proline content in grains was higher than that of proline content in flag leaves by tillage in fallow period. The relation between proline content in flag leaves and the activity of GDH in flag leaves, proline content in grains and the activity of GS in flag leaves was closed in 15 days after wheat harvest by tillage. The relation between proline content in flag leaves and the activity of GDH in grains was closed in 45 days after wheat harvest by tillage. But there were no relation between proline in grains and two enzymes in 45 days after wheat harvest by tillage. 【Conclusion】The above results suggested that tillage in fallow period especially in dry year had better soil moisture conservation effects, benefit for decreasing the proline content in flag leaves and proline content in grains at early filling stage, relieving drought degree of wheat suffered. As proline content had a great relation with nitrogen metabolism enzyme, so grains protein accumulation was affected. Tillage stage had great regulation effects on soil water, post-anthesis proline accumulation and grains protein accumulation. Deep tillage after rainfall benefit for grains protein formation.
    Change of Maize Growth Period and Its Impact Factor in China
    DI Zhi-Fen, HU Wei, YAN Chang-Rong, LIU Qin, LIU Shuang
    Scientia Agricultura Sinica. 2012, 45(22):  4587-4603.  doi:10.3864/j.issn.0578-1752.2012.22.005
    Abstract ( 618 )   PDF (3296KB) ( 1206 )   Save
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    【Objective】 In the background of global climate change, the sowing time, maturity time and growth period of maize, and the changes of climate resource in China were analyzed.【Method】After collection of maize growth period data of 2414 counties and meteorological data of 618 meteorological stations from 1971 to 2010, by using the Kriging method, the distribution of maize sowing time and maturity time of 1970s and 2000s were drawn, and the annual temperature, precipitation and solar radiation were calculated in those two periods. Taking the crops area as the basic unit, the regression equation between agro-climatic resources and the change of maize sowing time and maturity time were built in different areas. Put B2 scenario data from PRECIS model into the equations, the maize growth period were predicted in 2030s. 【Result】 Compared with 1970s, the sowing time in 2000s was unchanged in Northeast soybean, spring wheat and beet area; while in other agricultural planting areas were advanced about 1 to 15 days. And the maturity time was delayed 11 days and 3 days in Northeast soybean, spring wheat, beet area and Northern plateau small grains, beet area, while other areas advanced 3 to 12 days. The maize growth period shortened about five days in Yunnan-Guizhou Plateau rice, corn, tobacco area, which remained unchanged in cotton, wheat, oil, tobacco, fruit area, South double cropping of rice, tropical crops, sugarcane area and Northwest Oasis wheat, cotton, beet, grape area, while in other regions has extended longer. In 2030s of B2 scenarios, the maize sowing time will delay 2 to 5 days in Northeast soybean, spring wheat, beet area, while in other agricultural planting areas may be advanced 2 to 19 days comparing to 2000s. The maturity time will delay 4-15d in Northeast soybean, spring wheat, beet area, Northern plateau small grains, beet area and South double cropping of rice, tropical crops, sugarcane area, which will advance 2 to 12 days in cotton, wheat, oil, tobacco, fruit area,Yangtze River rice, cotton, oil, mulberry, tea area,Sichuan and Shaanxi Basin rice, corn, potato, citrus, mulberry area and Yunnan-Guizhou Plateau rice, corn, tobacco area, and it will essentially unchanged in South Hills double cropping of rice, tea, citrus area and Northwest Oasis wheat, cotton, beet, grape area. Comparing to 2000s, the maize growing period in 2030s will reduce 3 to 6 days in cotton, wheat, oil, tobacco, fruit area and Yunnan-Guizhou Plateau rice, corn, tobacco area, and in other regions it will extend 2 to 15 days. 【Conclusion】The climate is changing to warming, dry and low radiation. By impact of temperature, precipitation and solar radiation, there exists an objective change of maize growth stage in different agricultural planting areas, and the sowing time will advance in most part of China, the maturity time will become more complex, and the growing period of maize will extend in most part of China.
    PLANT PROTECTION
    Progress and Perspectives in Infection Mechanism of Ustilaginoidea virens
    HU Dong-Wei, WANG , SHU
    Scientia Agricultura Sinica. 2012, 45(22):  4604-4611.  doi:10.3864/j.issn.0578-1752.2012.22.006
    Abstract ( 876 )   PDF (735KB) ( 1859 )   Save
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    Rice false smut has been an important disease throughout the world, and there are still many puzzles remained in the infection mechanism of the pathogen Ustilaginoidea virens. Here the progress in recent years on the pathogen infection, and problems were reviewed and the perspectives of the research were outlined. It is found that the pathogen could invade rice coleoptiles and roots at the young seedling stage and the filaments of stamen at the earlier booting stage. The pathogen does not form typical appressorial structure, and the hyphae invade and extend intercellularly. The fungal hyphae do not penetrate through the host cell wall. It is not clear if the pathogen colonized in the young seedlings can extend to the spikelets and form the ball-like symptom. At rice booting stage, the pathogen attacks exclusively rice filaments and the secondary hyphae can infect the outer layers of cells on lodicules and stigmas occasionally. The pathogen can not infect the ovary and anthers. The pathogen does not kill the host cell during its development, typical of a biotrophic parasite. Future researches may be focused on the infection progression of young seedlings and on the biochemical and molecular mechanisms of the organ-selected invasion.
    Screening, Identification and Biocontrol Potential of Antagonistic Fungi Against Strawberry Root Rot and Plant Growth Promotion
    SHEN Guang-Hui, XUE Quan-Hong, ZHANG JING , DUAN Jia-Li, WANG Dong-Sheng, YANG Xing-Hua
    Scientia Agricultura Sinica. 2012, 45(22):  4612-4626.  doi:10.3864/j.issn.0578-1752.2012.22.007
    Abstract ( 744 )   PDF (1248KB) ( 1362 )   Save
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    【Objective】The objective of this study is to verify the suitability of a rapid screening program for biocontrol fungi based on root-zone microflora differentiae between healthy and root rot diseased strawberry plants. 【Method】 The isolated antagonistic fungi were identified according to colony and morphological characteristics observed by scanning electron microscope (SEM) and rDNA-ITS sequences analysis. Mycelium growth rate method and slide dual culture method were used to investigate antagonistic activity of cell-free culture filtrate and the antagonistic effect of antagonistic fungi against soil-borne pathogens, respectively. The seed germination promotion activity of culture filtrate was measured by Petri dish assays. A pot experiment was conducted to evaluate the control efficiency of antagonistic fungi against strawberry root rot caused by Cylindrocarpon macrodidyma CF9 and plant growth promotion effect. Colonization capacity and microbial flora were also determined by dilution plate count method. 【Result】Strain HF3 and strain HF7 were identified as Penicillium griseofulvum and Aspergillus terreus, respectively. The cell-free culture filtrate both of two strains exhibited strong antagonistic effect on mycelium growth of test pathogens. The mycelium inhibitory rate of strain HF3 culture filtrate on Rhizoctonia solani and Verticillium dahliae were 100.0% after 96 h. It was also observed that HF3 broke the hyphae of C. macrodidyma CF9, such as contorting, slimmer, bulging, dissolved, protoplasm condense. It was observed that 103 and 104 diluted-fold filtrate of two strains enhanced the melon seed germination and growth, 104 diluted-fold filtrate of HF7 promoted seed germination, plumule and radicle growth of watermelon. In a pot experiment, the control efficiency against root rot of strawberry of HF3 and HF7 were 53.0% and 46.9%, respectively. Moreover, two antagonistic strains exhibited strawberry plant growth promotion as well as fruit yield enhancement. HF3 and HF7 efficiently colonized strawberry root with rhizoplane densities 2.23×105, 1.02×105 CFU•g-1 dry soil, respectively. The population of C. macrodidyma CF9 in root-zone were reduced largely. HF3 and HF7 also balanced the root-zone microbial flora when inoculated with C. macrodidyma CF9. 【Conclusion】The rapid screening program based on the root-zone microflora differentiae between healthy and root rot strawberry plant is a simple and reliable way to seek for strong potential biocontrol agents for the field practice. HF3 and HF7 isolated from healthy strawberry native root-zone have better potential for the control of strawberry root rot.
    Changes of Physiological Indexes of Jujube, Peach, Cherry and Grape Leaves Damaged by Apolygus lucorum in Northern China
    GAO YONG , MEN Xing-Yuan, YU YI , ZHOU Hong-Xu
    Scientia Agricultura Sinica. 2012, 45(22):  4627-4634.  doi:10.3864/j.issn.0578-1752.2012.22.008
    Abstract ( 721 )   PDF (556KB) ( 609 )   Save
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    【Objective】 The objective of this study is to elucidate the relationship between changes of physiological indexes in different fruit tree leaves of jujube, peach, cherry and grape and preference degree of Apolygus lucorum, and to analyze the physiological defense mechanism of damaged leaves by A. lucorum, providing a scientific basis for effective control of the pest. 【Method】The damage indexes of different fruit trees were investigated in the orchard, and biochemical analyses were conducted to study changes of various physiological indices in damaged leaves of different fruit trees. 【Result】Soluble sugar contents increased in four fruit tree leaves except peach leaves after damaged by A. lucorum, and increased up to 87.83% in jujube leaves. The content of protein decreased in four fruit trees leaves, and no significant difference in protein was found between pierced and contrast leaves except peach leaves. Free amino acid contents increased in four fruit tree leaves, with the increase rate having a positive correlation with damage index, contrast to the piercing of A. lucorum. The POD activities in four fruit tree leaves showed an increasing trend, and increased by 112.92% in jujube leaves. The SOD activities increased in other tree leaves except cherry leaves, with a high increase rate of 40.95% in jujube leaves. No significant difference in CAT was found between pierced and contrast leaves of four fruit trees. 【Conclusion】After damaged by A. lucorum, the changes of physiological indexes in different kinds of leaves were different. The changes of soluble sugar, amino acid contents, POD and SOD activities showed a positive correlation with the preference of A. lucorum, while the protein contents and CAT activities showed no significant correlation with the preference of A. lucorum.
    SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT
    Effects of Different Application Rates of DMPP and DCD on Nitrogen Transformation in Calcareous Soil
    SHI Mei, LIANG Dong-Li, MAN Nan, GUO Lu, ZHAO Wen-Long, WANG Chao-Hui
    Scientia Agricultura Sinica. 2012, 45(22):  4635-4642.  doi:10.3864/j.issn.0578-1752.2012.22.009
    Abstract ( 807 )   PDF (566KB) ( 646 )   Save
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    【Objective】A simulating experiment was carried out to study the effects of different concentrations of DMPP and DCD on nitrogen transformation in calcareous soil, and the best application rate was screened to provide references for agricultural practice.【Method】In the same incubation condition (soil moisture: 60% of water hold capacity, 25℃), the effects of different concentrations of DMPP (0.5%, 1%, 2.5% and 5% of applied pure N) and DCD (2.5%, 5%, 10% and 15% of applied pure N) on nitrogen forms in calcareous soil were compared.【Result】The results showed that compared to CK, the contents of soil ammonium nitrogen in DMPP and DCD treatments were higher, while nitrate and nitrite nitrogen concentrations were significantly lower. Application of DMPP and DCD could significantly (P<0.05) decrease the ammonium oxidation rate and the half-lives of NH4+ in soils increased from 3.6d in CK treatment to 14.1-17.1 d in DMPP treatments or 13.1-26.8 d in DCD treatments. No significant difference in the ammonia oxidation rates was observed in different DMPP treatments, however, the rates decreased with the rising of DCD concentrations. Among all nitrification inhibitor treatments, the minimum ammonia oxidation rate was found in 2.5% DCD treatment, while the maximum rate was observed in 15% DCD. The ammonia oxidation rates in DCD treatments (except 2.5% treatment) were higher than those in DMPP treatments. 【Conclusion】Application of DMPP and DCD could inhibit the oxidation of ammonium. No significant difference was observed in DMPP treatments, whereas an evident dose-effect relationship was found in DCD treatments. No significant difference was found between 5% DCD treatment and DMPP treatments (P<0.05). As a result, the recommended DMPP and DCD rate in carcalous soil was 0.5% and 5% of pure nitrogen, respectively.
    Study on Potassium Release Kinetics of Several K-Bearing Minerals by Sequential Extraction of Different Acid Solution
    WANG Jin, LI Xiao-Kun, LU Jian-Wei, WANG Zheng, ZHAN Li-Ping
    Scientia Agricultura Sinica. 2012, 45(22):  4643-4650.  doi:10.3864/j.issn.0578-1752.2012.22.010
    Abstract ( 768 )   PDF (530KB) ( 765 )   Save
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    【Objective】Potassium release and kinetics of different K-bearing minerals were studied to provide scientific evidence for reasonable evaluation of K fertility and high efficient utilization of soil potassium.【Method】Different K-bearing minerals (biotite, muscovite, orthoclase and microcline) were extracted successively with low-molecular weight organic acids (oxalic acid, tartaric acid) and inorganic acids (HNO3) to study potassium release and kinetics.【Result】The results showed that the amount of K from biotite extracted successively by oxalic acid, tartaric acid and HNO3 by increased significantly 2.7 times, 4.1 times and 22.3 times compared to that of by water, respectively. The release amount of K from muscovite increased by 61.2%, 106.5% and 226.8%, respectively. The release amount of K from orthoclase increased by 39.0%, 87.6% and 154.6%, respectively. The release amount of K from microcline increased by 44.5%, 88.9% and 158.7%, respectively. First order equation, power function, parabolic diffusion equation and Elovich equation were used to describe the release of K from K-bearing minerals. All the correlation coefficients (r) of the kinetic equations were from 0.708 to 1.000 which showed the most significant correlation (r0.01=0.549).【Conclusion】The amount of potassium released from K-bearing minerals increased significantly by the extractants, and it differed in different K-bearing minerals in order of biotite > muscovite > microcline ≈ orthoclase. The power function was the best model to describe the K release of biotite, orthoclase and microcline, and Elovich equation was the best model for muscovite.
    HORTICULTURE
    Obtaining Dodecaploid Interspecific Hybrid in Strawberry and Its Backcross
    LEI Jia-Jun, XUE Li, DAI Han-Ping
    Scientia Agricultura Sinica. 2012, 45(22):  4651-4659.  doi:10.3864/j.issn.0578-1752.2012.22.011
    Abstract ( 791 )   PDF (713KB) ( 1247 )   Save
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    【Objective】The backcross between higher ploid interspecific hybrids and strawberry cultivars was beneficial to broadening genetic background of modern cultivated strawberry and breeding of new cultivars. 【Method】 The dodecploid interspecific hybrid YH15-10 (2n=12x=84) was obtained from the cross between Fragaria × ananassa cv. Yuhime (2n=8x=56) and the wild pentaploid strawberry accession Heilongjiang 7 (2n=5x=35) native to China. The backcross between the dodecaploid interspecific hybrid YH15-10 and strawberry cultivars ‘Hokowase’ and ‘Honeoye’ were carried out. The ploidy, botanical characteristics, pollen size and viability, and fruit traits of the offspring were investigated. 【Result】 The YH15-10 had relatively few leaves, 4.4 inflorescences per plant and 8 to 25 flowers per inflorescence in the open field. The fruits were red, mostly abnormal, in which the maximum fruit weight was 10.5 g. The flesh was yellowish white with obvious aroma. When YH15-10 was used as female parent, no seedlings were obtained. When YH15-10 was used as male parent, 83 offspring was obtained. The dodecploid YH15-10 had large, middle and small pollens, and the pollen viability was similar to that of strawberry cultivars. The octoploid, decaploid, hendecaploid and dodecploid seedlings were obtained from Hokowase × YH15-10. Two seedlings IH1-5 (10x) and IH1-7 (8x) with high vitamin C of 0.95 mg•g-1 and 1.07 mg•g-1, respectively, were selected. Their fruits were sweet, aromatic, but small, with the maximum fruit weight of 10.4 g and 9.6 g, respectively. 【Conclusion】 This paper gave a good example for obtaining higher ploid strawberry. The dodecploid interspecific hybrid YH15-10 was helpful to develop new strawberry cultivars. Some seedlings with excellent quality, high vitamin C and high aromatic compound content were obtained from the backcross between the dodecaploid interspecific hybrid YH15-10 and strawberry cultivars. These high ploidy offspring could be further used as the parents to breed new strawberry cultivars.
    STORAGE·FRESH-KEEPING·PROCESSING
    Effects of Hydrostatic High Pressure and Temperature on the Micro- Organisms of Fresh-Cut Lettuce and During Its Shelf Life
    ZHANG Xue-Jie, YE Zhi-Hua
    Scientia Agricultura Sinica. 2012, 45(22):  4660-4667.  doi:10.3864/j.issn.0578-1752.2012.22.012
    Abstract ( 496 )   PDF (562KB) ( 904 )   Save
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    【Objective】There exists micro-organism safety problem for fresh cut lettuce, so the high hydrostatic pressure (HHP) and temperature were combined to see if there was a synergetic effect on reducing the micro-organism counts, and the micro-organism counts of fresh cut lettuce processed by HHP were also needed to be understood during shelf life.【Method】Aerobic plate counts and coliform counts of fresh cut lettuce were investigated after treated by 50 MPa, 100 MPa and 200 MPa for 5 min and 20 min at 5℃, 15℃ and 25℃, respectively, and the micro-organism counts of fresh cut lettuce processed by HHP during 6 days shelf life at 4℃ were also analyzed.【Result】A significant synergetic role was existed between pressure (50-200 MPa) and time (5-20 min) on reducing the aerobic plate counts and coliform counts of fresh cut lettuce (P<0.01), but temperature had no synergetic effects with pressure and time on reducing the micro-organism counts(P>0.05). The treatment with 200 MPa for 20 min reduced aerobic plate counts and coliform counts of fresh cut lettuce by 0.42 log CFU/g and 0.71 log CFU/g, respectively. Whatever HHP treated or not, aerobic plate counts increased with the extending of shelf life at 4℃, at the 6th day, the aerobic plate counts increased by 1.0 log CFU/g, but HHP treatments induced more microbes growth. The coliform counts decreased during shelf life, especially in HHP treatment, which showed non-detected counts at the 6th day, while the control still had 9% coliform counts.【Conclusion】High hydrostatic pressure reduced the aerobic plate counts and coliform counts of fresh cut lettuce significantly, but temperature (5-25℃) did not show the synergetic effect. During 6 days shelf life at 4℃, the coliforms counts of fresh cut lettuce treated by HHP was inhibited significantly, but the aerobic plate counts increased more than that of the control. Like other processing technologies, HHP also needs other synergetic factors such as HHP resistant varieties, HACCP and so on to realize the assurance of quality and safety of fresh cut fruits and vegetables simultaneously.
    ANIMAL SCIENCE·RESOURCE INSECT
    Effects of Degradable Protein and Non-Fiber Carbohydrates on in Vitro Ruminal Fermentation, Microbial Synthesis, and Populations of Ruminal Cellulolytic Bacteria
    ZHAO Xiang-Hui, LIU Chan-Juan, LIU Ye, LI Chao-Yun, YAO Jun-Hu
    Scientia Agricultura Sinica. 2012, 45(22):  4668-4677.  doi:10.3864/j.issn.0578-1752.2012.22.013
    Abstract ( 865 )   PDF (699KB) ( 741 )   Save
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    【Objective】 The objective of this study was to investigate the effects of levels of rumen degradable protein (RDP) and sources of non-fibre carbohydrates (NFC) on ruminal fermentation, microbial synthesis, and populations of ruminal cellulolytic bacteria using the rumen simulation technique (Rusitec). 【Method】 The experiment was a 2×4 factorial arrangement with four NFC types (corn starch, sucrose, pectin, inulin) each combined with two levels of RDP obtained by supplementing with 0 g•d-1 (low RDP) or 1.56 g•d-1 (high RDP) sodium caseinate. 【Result】 Apparent disappearance of dry matter and organic matter was greater (P<0.01) for the main effect means of sucrose and pectin than for other treatments. A NFC×RDP interaction (P<0.01) was observed for apparent neutral detergent fibre disappearance, which tended to be lower for sucrose (P=0.10) and pectin (P=0.09) than for starch treatment under low RDP conditions, but did not differ among treatments under high RDP conditions. The 16S rDNA copies of Ruminococcus albus were greater for the main effect means of pectin than for starch treatment. There were NFC×RDP interactions for 16S rDNA copy numbers of R. flavefaciens in both liquid and solid fractions and Fibrobacter succinogenes in liquid fraction. Compared with starch treatment, R. flavefaciens in solid fraction tended to be lower (P=0.06) for sucrose treatment under low RDP conditions and F. succinogenes in liquid fraction was lower (P<0.01) for inulin treatment under high RDP conditions. Increasing dietary RDP increased total volatile fatty acids production (P<0.01) and total microbial nitrogen (MN) flow (P<0.01) in all treatments. The molar proportion of acetate and the ratio between acetate and propionate were both the greatest (P<0.05 and P<0.01, respectively) for the main effect means of pectin among treatments. Butyrate molar proportion was greater (P<0.01) for sucrose and inulin treatments than for other treatments regardless of RDP level. Total MN flow did not differ among treatments under low RDP conditions, but sucrose (P<0.01) and pectin (P=0.10) produced greater MN than starch with increased RDP. The efficiency of available N was lower for the main effect means of starch than for sucrose (P=0.04) and pectin (P=0.05) treatments.【Conclusion】 Dietary RDP level, NFC type, and their interaction affected ruminal fermentation, microbial synthesis, and cellulolytic bacteria populations, and under sufficient ruminal available N sucrose and pectin had greater advantage in microbial N synthesis than starch.
    Developmental Changes of Gene Expression of GHR and IGF-Ⅰ Genes and Their Association Analysis with Meat Quality Traits in Hu Sheep
    SUN Wei, LI Da, MA Yue-Hui, GUAN Wei-Jun, CHU Ming-Xing, DING Jia-Tong, LI Bi-Chun, ZHANG You-Fa, CHEN Ling, WU Wen-Zhong, ZHOU Hong
    Scientia Agricultura Sinica. 2012, 45(22):  4678-4687.  doi:0.3864/j.issn.0578-1752.2012.22.014
    Abstract ( 505 )   PDF (625KB) ( 652 )   Save
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    【Objective】The objective of this study was to discuss the developmental changes of gene expression of growth hormone receptor (GHR) and insulin-like growth factor-Ⅰ(IGF-Ⅰ) and their association analysis with meat quality traits , and the relationship of the expression level between GHR gene and IGF-Ⅰgene in Hu sheep. 【Method】The developmental changes of gene expression of GHR gene and IGF-Ⅰgene on the early growth of Hu sheep were detected by real-time fluorescent quantitative RT-PCR. 【Result】The results were as followes: With increasing age after birth, the GHR expression trend of ewes was up-down-up-down-up, and 6-month reached the top. The GHR expression trend of rams was that 2-day-old to 2-month-old was increasing, 2-month-old to 4-month-old was decreasing, 4-month-old to 6-month-old was increasing and reached the top. With the increasing age after birth, the IGF-Ⅰgene expression trend of ewes was increasing from 2-day-old to 6-month-old which had the top expression. The IGF-Ⅰgene expression trend of rams was that at 2-day-old firstly increased to a peak at one-month-old, 1-month-old to 3-month-old had a decreasing process and reached the same level which was close to the newborn, and then increased with the increasing age, and 6-month-old reached the top. Most growth phases had a significant difference or extreme significant difference in GHR and IGF-Ⅰand the expressions of GHR and IGF-Ⅰbetween most rams and ewes that at the same growth phase had a significant difference or extreme significant difference. The results showed that the expressions of GHR and IGF-Ⅰhad a significant positive correlation, (0.01<P<0.05) the expressions of GHR and IGF-Ⅰgenes had a extreme significant positive correlation (P<0.01) with diameter of muscle fibers and a extreme significant negative correlation (P<0.01) with density of muscle fibers, and the expressions of GHR had a extreme significant positive correlation (P<0.01) with shear force of muscle fibers, the expression of IGF-Ⅰhad a significant positive correlation with shear force of muscle fibers (0.01<P<0.05). 【Conclusion】The results showed that different stages and different genders had important influences on the expressions of GHR and IGF-Ⅰgenes in sheep skeletal muscle. After birth, the expressions of the two genes did not always increase or decrease, the turning points of different genes expression were not at the same time. The expression of GHR and IGF-Ⅰhad a significant positive correlation in early muscle traits of Hu sheep. GHR and IGF-Ⅰgene can be regarded as the candidate gene for the trait of meat quality in Hu Sheep.
    Construction and Identification of Normalized Subtractive cDNA Library of Plumage Color-Related Genes in Mule Duck
    ZHENG Nen-Zhu, CHEN Xiao-Yan, LU Li-Zhi, ZHU Zhi-Ming, MIAO Zhong-Wei, XIN Qing-Wu, CHEN Hui, XIAO Tian-Fang
    Scientia Agricultura Sinica. 2012, 45(22):  4688-4696.  doi:10.3864/j.issn.0578-1752.2012.22.015
    Abstract ( 524 )   PDF (534KB) ( 539 )   Save
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    【Objective】 The aim of this study was to isolate plumage color related-genes in mule duck and explore its molecular mechanism. 【Method】 A normalized subtractive library of plumage color related-genes of mule duck was constructed. White plumage skin and black plumage skin were adopted respectively as the tester and driver, and a duplex-specific nuclease (DSN) normalized subtractive hybridization method was used to construct the library, and real-time PCR was employed to identify the quality of the library.【Result】Results showed that 64 genes with the average size of 1 031 bp were obtained by selecting and sequencing 144 positive clones randomly. Nucleotide BLAST homological analysis incidated that 21 genes had similarities to known genes which enjoy 92.8% homology, and 43 genes were not matched which presumably may be new genes related to plumage color. Geneontology displayed that these known genes were involved in many biological processes such as signal transduction, cell structure, material transport, apoptosis, cell and organism defense, transcription and expression regulation,and had different correlations with formation and transshipment of pigment. 【Conclusion】 It was determined that the library had good quality and could enrich the genes of the white plumage via real-time PCR.
    Pathogenic Mechanism of Bombus patagiatus Infected by Nosema ceranae
    QIN Hao-Ran, HE Shao-Yu, WU Jie, LI Ji-Lian
    Scientia Agricultura Sinica. 2012, 45(22):  4697-4704.  doi:10.3864/j.issn.0578-1752.2012.22.016
    Abstract ( 728 )   PDF (787KB) ( 811 )   Save
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    【Objective】The objective of this study is to define the infectivity and pathogenic mechanism of Nosema ceranae to Bombus patagiatus. 【Method】 Traditional biology and ultrastructure under electronic microscope methods were used, and combined with the quantitative real-time PCR (qPCR) to explore the pathogenesis of N. ceranae to B. patagiatus. 【Result】 In the initial infection, the infected bees did not exhibit obvious external disease signs except decreased feeding and motor retardation. In the late period, the infected bees exhibited dispirited, weak and unable to fly. Through observation with light microscope, few N. ceranae but a lot of bacteria were found in the midgut of bees. N. ceranae mainly infected midgut of epithelial cells, the nuclear enlarged and out of shape, mitochondria become smaller even disintegrating and endoplasmic reticulum become disorders. However, the spores only infected the cytoplasm of the host instead of invading the nuclear, which lead to the disintegration of the mitochondria and cytoclasis. Quantitative analysis on RT-PCR showed that N. ceranae reached the highest level in the midgut and fat body 3-4 d after being infected and other organizations were barely detected.【Conclusion】N. ceranae can cross-species infect B. patagiatus and the pathological process starts with the pathological changes of intestinal cells, which lead to the cytoclasis and apoptosis.
    VETERINARY SCIENCE
    Construction and Animal Experiment of a Recombinant Adenovirus Expressing NcSAG1 Protein of Bovine Neospora caninum
    JIA Li-Jun, ZHANG Shou-Fa
    Scientia Agricultura Sinica. 2012, 45(22):  4705-4712.  doi:10.3864/j.issn.0578-1752.2012.22.017
    Abstract ( 562 )   PDF (586KB) ( 524 )   Save
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    【Objective】A recombinant adenovirus expressing NcSAG1 protein of bovine N. caninum was constructed. Balb/c mice were immunized with the recombinant adenovirus to evaluate the levels of humoral and cellular immune responses. 【Method】NcSAG1 gene of bovine N. caninum was amplified by PCR. pMD18-T-NcSAG1 and pCR259- NcSAG1 were constructed. The correct pCR259-NcSAG1 was transformed into HighQ-1 Transpose-Ad™ 294 and HighQ-1™ competent cells to construct transpose-Ad-NcSAG1 recombinant adenovirus. Coated with liposome, Transpose-Ad-NcSAG1, linearized by PacI, was transfected into QBI- HEK293 cells to package recombinant adenovirus Ad5-NcSAG1. The recombinant adenovirus Ad5-NcSAG1 was detected by PCR. The expression of NcSAG1 gene in QBI-HEK293 cells was detected by Western blotting. After the virus titer was determined, the virus fluid was collected to inoculate Balb/c mice and the levels of IgG antibody and cytokines IFN-γ, IL-4 in the sera were measured to evaluate the recombinant adenovirus effect. 【Result】The size of NcSAG1 gene was 982 bp. The nucleotide sequence of the gene shared 99.2% homology with that in GenBank (AF132217). The recombinant adenovirus Ad5-NcSAG1 was successfully packaged in 293 cells. The protein expressed by Ad5-NcSAG1 was 33kD and had good reactogenicity. The titer of the recombinant adenovirus Ad5- NcSAG1 was 1010TCID50/mL. The Ad5-NcSAG1 recombinant adenovirus induced Balb/c mice to produce strong humoral and cellular immune responses. 【Conclusion】 The recombinant adenovirus Ad5-NcSAG1 was successfully constructed. It could induce Balb/c mice to produce strong humoral and cellular immune responses. This study has laid a solid foundation for the clinical experiment of the novel vaccine against N. caninum.
    Analysis of Immunological Characteristics of Echinococcus Granulosus Adult Worm Surface Membrane -Associated Glycoantigen
    GU Nu-尔?Tu-尔Xun, MI Xiao-Yun, ZHANG Zhuang-Zhi, SHI Bao-Xin, TU 尔Hong-?Yi-Mi-Ti, JIN Ying-Hong, ZHANG Mei, CHENG Xiao-Bo, ZHANG Xu, ZHAO Li, ZHANG Wen-Bao
    Scientia Agricultura Sinica. 2012, 45(22):  4713-4719.  doi:10.3864/j.issn.0578-1752.2012.22.018
    Abstract ( 546 )   PDF (547KB) ( 434 )   Save
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    【Objective】 The immunological characteristics of the carbohydrate antigen (glycoprotein) of E. granulosus adult surface membrane were explored in this study . 【Method】 The freez-thaw E. granulosus adult worm lysis was digested by protease K, and centrifuged to collect supernatant as crude glycoantigen materials, which was identified by SDS-PAGE, quantified by sulfuric acid anthrone method. Then, the Balb/c mice were injected hypodermically by the material six times for anti-serum, which was collected to measure immunoglobulin (IgG, IgM and IgA) by ELISA, and to determine the specificity by western- blot method. To localize the site of the antigen composition in the E. granulosus adult worm by IFA. 【Result】 The SDS-PAGE showed that there was no visible band on the gel. This suggested that the proteins of the parasite surface membrane were degraded completely. The concentration of glycoantige was 2.54mg•mL-1 in the preparation. ELISA showed that the specific antibodies (IgG, IgM, and IgA) were rised gradually with the increase of the immunization times, and the positive/negative ration (P/N) of IgG, IgM and IgA equals to 4.9, 3.2 and 6.4, respectively. Comparatively, the specific IgE was not detected. Western blotting showed that the E. granulosus adult worm surface membrane glycoantigen and native proteins could be recognized by the anti-serum. IFA proved that the glycoantigen was located on the surface membrane of E. granulosus adult worm. 【Conclusion】 The glycoantigen of E. granulosus adult worms digested proteinase K has good immunogenicity and reactivity, and could be used to develop vaccine candidates and diagnosis material.
    RESEARCH NOTES
    Detection of the Relative Content of Ustiloxin A in Rice False Smut Balls and Correlation Analysis Between Pathogenicity and Ustiloxin A Production of Ustilaginoidea virens
    YIN Xiao-Le, CHEN Zhi-Yi, LIU Yong-Feng, YU Jun-Jie, LI Yan, YU Mi-Na
    Scientia Agricultura Sinica. 2012, 45(22):  4720-4727.  doi:10.3864/j.issn.0578-1752.2012.22.019
    Abstract ( 572 )   PDF (564KB) ( 669 )   Save
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    【Objective】The objective of this study is to define the active components of crude toxin produced by Ustilaginoidea virens, to analyze the ustiloxin A production of false smut balls in different areas, and to discover the correlation between pathogenicity and ustiloxin A production of the fungus.【Method】The crude toxin of U. virens was extracted from false smut balls by acetone, methanol and water, respectively, and the toxic effect was assayed and indicated by inhibition to wheat seed germination. The active components of the crude toxins were studied by liquid chromatography mass-spectrometry (LC-MS) and UV absorption spectra. Ustiloxin A production of 224 false smut balls collected from different areas in China was analyzed by high performance liquid chromatography (HPLC). The pathogenicity of 52 isolates of U. virens was examined through inoculating the susceptible rice cultivars, Liangyoupeijiu. The correlation between pathogenicity and ustiloxin A production of the fungus was analyzed by using SPSS software.【Result】The crude toxin extracted with water and methanol had higher inhibition to wheat radicle growth with the inhibition rate of 59.6% and 52.9%, respectively, while the crude toxin extracted with acetone had lower inhibition. The molecular weight of the active ingredient Ⅱwas 673.9 by determination with LC-MS. Combined with the UV spectra assay, ingredient Ⅱcould be proved to be ustiloxin A. It was found that there was a significant difference in the ustiloxin A production among false smut balls collected from different areas. However, correlation analysis indicated that no significant correlation between pathogenicity of the fungus and its ustiloxin A production(R=0.222, P=0.114).【Conclusion】Water extract of false smut balls caused by U. virens contained ustiloxin A. And a significant difference in ustiloxin A production was found in false smut balls collected from different areas. There may be no association between pathogenicity and ustiloxin A production of the fungus.
    Ananlysis of Differential Stigma Proteins Between a Pollination- Deficiency Mutant in Brassica napus L.and Its Wild Type
    LI Chun-Hong, FU San-Xiong, QI Cun-Kou
    Scientia Agricultura Sinica. 2012, 45(22):  4728-4737.  doi:10.3864/j.issn.0578-1752.2012.22.020
    Abstract ( 643 )   PDF (677KB) ( 873 )   Save
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    【Objective】The difference in protein expression was identified between a pollination-deficiency mutant FS-M1 in Brassica napus L. and its wild type at proteomics level. 【Method】 Two-dimensional electrophoresis (2-DE) was used to study the variation expression of stigma proteins between FS-M1 and its wild-type (NY10). The characteristics and functions of proteins expressed up-regulated in the B. napus L. stigma were analyzed with MALDI-TOF-TOF/MS and Protein Data Bank. 【Result】 A total of 33 up-regulated proteins expressed in the wild-type stigma were identified, which were involved in 7 functional categories, including stress response and defense, regulation of redox homeostasis, carbohydrate metabolism, proteolysis proteins, protein folding, amino acid and nitrogen metabolism, nucleotid metabolism, and unclassified. 【Conclusion】 The functions of protein up-regulated in the wild-type stigma were extensive,which could be related to pollination regulation of B. napus L..
    Quality Analysis of Spirulina Products Using Three-Step Infrared Spectroscopy
    LIU Hai-Jing, SUN Su-Qin, LI An, HA Yi-Ming
    Scientia Agricultura Sinica. 2012, 45(22):  4738-4748.  doi:10.3864/j.issn.0578-1752.2012.22.021
    Abstract ( 570 )   PDF (1145KB) ( 796 )   Save
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    【Objective】 Fourier transform infrared spectroscopy (FTIR) was used to analyze the principle components in natural Spirulina, Spirulina powder and Spirulina tablet. This could provide a fast, accurate and effective method for quality detection and authenticity test. 【Method】FTIR spectra of two natural Spirulina, four Spirulina powder and four Spirulina tablets were collected. Original IR spectra, second derivate and two-dimensional correlation IR spectra were analyzed to determine the major absorption functional group, main component and differences between samples. Scanning electron microscope images, protein contents and amino acid composition were used to explain the differences in FTIR spectra. 【Result】 Natual Spirulina had three saccharides characteristic peaks in original IR spectra at 1 154/1 156 cm-1, 1 079 cm-1 and 1 039/1 035 cm-1. In the range of 1 000- 1 230 cm-1, natural Spirulina had five auto-peaks at 1 161, 1 138, 1 083, 1 054 and 1 026 cm-1 in 2D-IR correlation spectra. Saccharides characteristic peaks in Spirulina powder and Spirulina tablets were different from natural Spirulina in shape and position and they had fewer atuopeaks in 2D-IR spectroscopy. The content of α-helix in natural Spirulina protein was 24.6 % while the content decreased to 15.0% in Spirulina powder and Spirulina tablets. The amide band in 2D-IR spectroscopy of natural Spirulina was smooth and separate absolutely while amide band of Spirulina powder and Spirulina tablets was broad, bifurcate and hardly separate. Protein contents and amino acid composition also showed that Spirulina products had higher protein content and different amino acid compositions compared with natural Spirulina.【Conclusion】FTIR spectra can distinguish the defferences in saccharides and protein of natural Spirulina, Spirulina powder and Spirulina tablet, thus providing an effective way for quality detection and authenticity test of Spirulina products.