Abstract:The purpose of the present paper is to study and develop indicators and procedures for the evaluation of genetic structure changes in plant germplasm conservation due to social and natural environment reasons. Some basic concepts in germplasm preservation were introduced at first. Then, six kinds of indicators for genetic diversity as a measure of genetic potential of a germplasm collection were presented, i.e. numbers of different entities at certain level, evenness of the entity distribution, genetic similarity and genetic distance, genetic variance and genetic coefficient of variation, multivariate genetic variation indices, and coefficient of parentage. It was pointed out that genetic dispersion did not provide a complete concept of genetic diversity if without any information from genetic richness. Based on the above, the indicators for genetic erosion as the genetic structure changes of germplasm conservation due to social reasons, the indicators of genetic vulnerability as the genetic structure changes of germplasm conservation due to environmental stresses, the measurement of genetic drift and genetic shift as the genetic structure changes of germplasm collection during reproduction or seed increase were reviewed and developed. Finally, the case studies on suitable conservation sample size of self-pollinated and open-pollinated populations were given for reference.

Abstract:Genetic diversity is important for breeding programs. Thirty-two selected microsatellite markers were used to detect genetic diversity among 80 salt-tolerant wheat cultivars. Totally 155 alleles were revealed among the 80 accessions. The number of alleles per SSR loci varied from 1 to 12, most of them from 4 to 8 and with the average of 4.75. The genetic distance among the 80 accessions varied from 0.26 to 0.81. Cluster analysis among the 80 accessions with salt tolerance showed that all the cultivars were clustered into two groups, that is the winter wheat group and the spring wheat group. Most accessions with same pedigree backgrounds were clustered into one subgroup. The difference of allelic variation in genome A, B and D was small, but genome B had the highest number of alleles.

Abstract:The psbL-psbJ region of chloroplast DNA (cpDNA) of 8 and 2 Hordeum species or subspecies from China and other countries, respectively, were investigated by PCR amplification and direct sequencing. It was indicated that the length of the psbL-psbJ region in all Hordeum species or subspecies was 365 bp, and no variable site was observed. The sequences of psbL-psbJ region were compared with that of rye (Secale cereale L. ) , wheat ( Triticum aestivum L. ) , rice ( Oryza sativa L. ) and maize (Zea mays L. ). The length of psbL gene was 117 bp in all materials, and no variable site was detected. The length of psbJ gene was 123 bp in all materials, and six variable sites were found. The length of psblL-psbJ inter-gene region was 125 bp in all materials except rice, while it was 126 bp in rice. There have 8 variable sites in psbL-psbJ inter-gene region. Using maize as outgroup, phylogenetic relationships were estimated by neighbor-jioning method. It suggested that the species or subspecies of Hordeum were genetically related to rye and wheat, which also belong to the tribe of Triticeae, while rice was related to maize.

Abstract:A doubled haploid (DH) population of 150 lines, derived from a cross between two Chinese com mon wheat varieties Hanxuan10 and Lumail4 was used in this study to map quantitative trait loci ( QTL) for water use efficiency (WUE) and related traits at seedling stage under water stress and control conditions, respectively. Mixed-model-based composite interval mapping analysis revealed that a total of 14 QTL of additive effect for the target traits were mapped on chromosomes 2A, 3A, 4A, 5A, 6A, 7A, 1B, 3B and 3D. The contribution range of these QTL to phenotypic variation was from 6.36% to 19.73% . Of these QTL, 10 were de tected under control condition: two for WUE, five for up-ground water use efficiency (UGWUE), one for down-ground water use efficiency (DGWUE) , and two for water consumed (WC); under water stress condition, one QTL was detected for each trait, respectively. There was no QTL regulating the same given trait to be mapped on the same marker interval under both conditions, implying that there were different QTL expression patterns under different water conditions. Some QTL may be employed to perform marker assisted selection in breeding.

Abstract:In 2003, 15 new materials from the Changjiang River valley cotton-growing area were identified for resistance to pink bollworm. Results showed that 8 (53.33% ) materials were highly resistant to pectinopho-ra gossypiella , 4 (26.67%) were resistant, 3 (20.00%) were moderately resistant. Fifty-five new materials were tested for their resistance to Fusarium wilt and 59 were for identification of resistance to Verticillium wilt. The results showed that 27 materials expressed disease resistance (account for 49.09%), 26 were tolerant (47.27%) and 2 susceptible (3.64%) to Fusarium wilt. Eight materials (13.56%) were resistant to Verticillium wilt, 43 (72.88%) were tolerant, 8 (13.56%) were susceptible.

Abstract:To estimate genetic diversity of Oryza rufipogon Griff. in Southeast region of Guangxi in China, a total of 301 individuals form 8 natural populations in Hezhou City, Fangchenggang City and Chongzuo City were analyzed using 25 microsatellites loci. A moderate to high level of genetic diversity was observed at population levels with the mean number of alleles (A) ranged from 2.0400 to 5.2000 (overall 10.2400). The effective number of alleles (Ae) ranged from 1.5337 to 2 .9921 (overall 5 .0221) . The mean expected heterozy-gosity (He) ranged from 0.2838 to 0.5840 (overall 0.7641). The observed heterozygosity (Ho) ranged from 0.2150 to 0.5753 (overall 0.4840). An estimate of the outcrossing rate (t = 0.4570) suggests that the species has a typical mixed-mating system. Furthermore, a moderate genetic differentiation ( Fst = 0.3459) was found among the populations studied, suggesting that 35.49% genetic variation existed among the populations. Moreover, microsatellite showed less deviation from Hardy-Weinberg expectation within and among populations (Fis = 0.2680, Fit = 0.4817) and a slight deficiency of heterozygotes. Eventually together with the pattern of genetic differentiation of natural populations of Oryza rufipogon in Southeast region of Guangxi, it could be suggested that the population QT, YJ, TJ be given priority for in-situ conservation.

Abstract:Factor analyses of 40 capsicum landraces in Hunan were carried out. These varieties were clustered to 7 groups. It was indicated that the numerical taxonomy basically revealed the genetic differences among the varieties. When the characteristic values reached over 75% in their accumulative contribution rates, these main factors' values would represent the genetic characteristics of these traits. Fruit weight, fruit number and plant shape were very important variables influencing the main factors of capsicum varieties. The main factor after Promax rotation could represent more precisely the genetic characteristic of varieties than these after Varimax rotation. Compared with other systematic clustering method, UPGMA would be better for the numerical taxonomy of the capsicum varieties.

Abstract:The Autumn-sown experiments in the precision seeding of small sowing amount for the winter wheat in two years were conducted during 2001 - 2003 in Beijing. The best yield for the DS 1 came to 5589.0 kg/hm2 at the sowing level of 22.5 kg/hm2 seeds from 2001 to 2002. The yield of Jing 411, Lumai 21, Jinmai 73 and DS 1 came to 8537.7, 7403.7, 7353.75 and 6836.25 kg/hm2, respectively at the sowing level of 22.5kg/hm2 seeds during 2002 - 2003. Rate of net photosynthesis, rate of transpiration, RS, COND and CINT in flag leaves showed that plants had vigorous physiological functions. Higher activities of nitrate reductase and SOD showed that plants had stronger metabolism. The number of spike per plant among yield components in these cultivars was relatively high.

Abstract:采用体细胞染色体计数和RAPD (Random Amplified Polymorphism DNA) 分子标记的方法鉴定甘蔗与蔗茅属间杂交种F1的真实性.结果表明,杂种F1材料01/47、01/85、01/120的2n＝80～82,染色体遗传方式为n 2n.用110个随机引物进行RAPD扩增,63个引物可获得双亲的RAPD多态性,其中3个引物OPC-19、OPE-2、OPF-4可在杂种F1材料01/64和01/120的RAPD扩增标记中显示出双亲的特征谱带,分别为父本3500bp和母本1300bp、父本1350bp和母本900bp、父本550bp和母本900bp.

Abstract:利用改进的高效液相色谱法(HPLC)检测了黑龙江省野生大豆(Glycine soja)、栽培大豆(G. max) 60份种质资源的异黄酮含量.结果表明,不同类型大豆种质资源异黄酮含量有明显遗传差异,变幅为416.2～6808.2μg/g,野生大豆高于栽培大豆,筛选出高异黄酮野生大豆种质资源4份、高异黄酮栽培大豆种质资源2份.

Abstract:Whitefly(Bemisia tabaci Gennadius)is one kind of serious soybean pests worldwide. Selection of resistant soybean cultivars is the most effective measure to control whitefly. However, there are not soybean cul-tivars resistant to whitefly now. Therefore, there is a need for evaluation of resistance of soybean germplasm to whitefly. Thus, this research was conducted with the objective of screening of soybean germplasm resistant to whitefly and understanding the resistant mechanism. Totally 223 cultivars were planted arranged in randomized complete block design with three replications at Shandong Academy of Agricultural Sciences, Crops Institute in 2004. The number of nymph in 2-4 instars of whitefly on every leaves of five plants and the pubescence growth shape were observed. Seed protein contents and fat contents of some resistant and susceptible cultivars were measured. The results showed that whitefly resistance of soybean germplasm was different. The number of nymph ranged from 0.4 to 80.0 per leave. Six cultivars, Huapidou, Dongxuan1, Hedou12, Langziwei, Henghe, and He7308 were resistant to the nymph of whitefly. The resistance to whitefly nymph was correlated with the pubescence growth shape of soybean cultivars. The order of whitefly resistance (from strong to weak) was germplasm with null, grovel, erect and acclivous pubescence. The damage of whitefly was correlated with seed protein content and seed fat content. The numbers of nymph rapidly increased with the seed protein contents' increase, but rapidly decreased with the seed fat contents' increase. According to the results, the resistance criterion based on nymph number per leave (NNPL) was suggested. That was immune as NNPL was 0, 0.1 - 3.0 highly resistant, 3.1-10.0 resistant, 10.1-20.0 susceptible, over 20.0 highly susceptible.

Abstract:Five foxtail millet varieties, including Lu 7060, Yangjiaohuang, Yugu No. 5, Jun 24 and Mar 51, were used for rapid drought tolerance evaluation. According to the germination rate in mannitol solution, relative water content (RWC) and water potential of leaves after mid-drought and seedling survival rate after severe drought, the variety Mar 51 was screened as the most drought-tolerant variety among the five varieties. Compared to other varieties, Mar 51 had a higher germination rate and higher relative water content after mid-drought. As a result, germination rate under osmotic stress and RWC could be considered as good indices of drought tolerance and used for rapid evaluation for drought tolerance of foxtail millet.

Abstract:Fiber quality of 108 cotton varieties with Fusarium and Verticillium wilt resistance in China was analyzed. Most of the varieties had 2.5% span fiber length above 29mm, whereas a few was with less than 27mm of 2.5% span fiber length. The mean of fiber strength was low, but there were several varieties possessing high fiber strength. The fiber micronaire readings was with high average. From the 1960s to the 1990s, the fiber quality of these varieties showed unobvious progress of genetic improvement. There was no obvious increase in averages of length, strength and micronaire, but the range of fiber length was widen and the upper limit value of length and strength went up gradually. Some varieties with finer fiber appeared in the 1990s. Varieties with good fiber quality were screened out, among them, 10 varieties with 2.5% span fiber length above 33mm, 10 with fiber strength over 33. 2cN/tex, 10 with fiber uniformity over 87.1 % , 10 with 3.8 - 4.3 micronaire readings, and 9 varieties possessed good comprehensive fiber quality.

Abstract:Forty-eight sorghum accessions were genotyped with 104 SSR markers using the TP-M13 automated fluorescent-labelled system. In the method, one reverse SSR primer was tailed with a M13 forward primer, which is called TP-M13, the second SSR primer was normal, and the third primer was the M13 forward primer labeled by FAM. The PCR fragments amplified by these three primers were detected using an automated fluorescent-labelled system (DNA sequencer such as ABI3700). The result indicated that the method had the advantages of high-throughput, sensitiveness, cost-effectiveness and high accuracy over some of other conventional methods. Therefore, the TP-M13 automated fluorescent detection system is suggested to be suitable for genotyping limited number of accessions by the use of a number of SSR markers.

Abstract:This experiment was carried out in Taipusi Banner of Inner Mongolia from 2001 to 2003. Totally 21 grasses introduced from America, Canada and originated in China were evaluated with their phenophase, hay yield and seed yield. The result showed that six among them had relatively strong adaptability as well as higher yield, so could be used as germplasm material for artificial grassland establishment and natural grassland improvement in this region.

Abstract:Identification and evaluation of 841 soybean accessions newly collected and stored in the National Genebank during 2002 - 2004 were carried out with regard to two major quality traits of protein and oil content. The results showed that protein and oil content exhibited normal distribution, and the greatest frequency was 41.01% to 42.00% and 20.01% to 21.00%, respectively. Compared with previously collected soybean germplasm, protein content of those newly collected presented decreasing trend; on the contrary, oil content and protein plus oil content presented opposite trend. It could be found, after comparing traits among four different types of germplasm, that protein level of landraces was higher than that of other three types of germplasm including lines, introduced materials and varieties; and that oil level and protein plus oil level of introduced materials were higher than that of other three types. Domestic germplasm possessed higher percentage of high protein soybean; and introduced germplasm possessed higher percentage of high oil and high protein plus oil soybean in comparison with domestic.

Abstract:Resistance to black rot of totally 1107 sweet potato germplasm were evaluated. 8 varieties(0.7% ) were evaluated as germplasm with high resistance and 128 varieties(11 .6% ) were evaluated as germplasm with resistance. Comprehensive evaluation such as the resistance to other diseases,the yields and the quality,were also done for the accessions with resistance to black rot disease.

Abstract:本文对47份不同甘蔗基因型的蔗汁品质性状进行简单回归和逐步回归分析.结果表明,蔗汁蔗糖分(Suc)与锤度(BX)、温度校正后锤度(BX′)、蔗汁旋光读数(0Z)以及转光度(pol)之间均呈线性回归,简单回归模型均达极显著水平(P＜0.01),决定系数(R2)分别为0.9393、0.9199、0.9861及0.9839.通过逐步回归分析和残差分析建立多重线性回归方程为Suc=0.05706 0.21488BX 0.181030Z,方差分析表明多重线性回归模型达极显著水平(P＜0.01),决定系数为0.9931.t测验表明,蔗汁蔗糖分的模型预测值与实测值间的差异不显著,相对误差平均为0.49%.

Abstract:对假茴芹体细胞染色体计数,并对其核型进行研究的结果表明,假茴芹的染色体数目为2n=22; 核型公式为2n=2x=22=14sm 8st,属于3B型.全组染色体总长92.80μm,长臂总长为66.83μm,核型不对称系数为72.02%.染色体总体积为264.40μm3.

Abstract:A PLS model for amylose content in brown rice and NIR spectral data was created using NIR technique. The coefficient of determination for cross validation amounted to 0.8429, maximum absolute error and average absolute error were 4.82% and 2.30%, respectively. The results indicated that FT-NIRS technique could be applied to screen rice germplasm resources effectively.

Abstract:Since 1949, about 23,890 cultivated varieties (lines) and 2,201 entries of wild rice have been introduced into China and evaluated most being used directly and/or indirectly in rice breeding and production. Among of them, 23 and 75 introduced varieties were cultivated annually over 66,700 hm2 and 6,670-66,700 hm2 in some years, respectively. The restorer lines (R lines), introduced directly and/or bred with foreign R descents, have occupied 95. 7% of total R lines used in hybrid rice. A large number of foreign rice materials have been utilized as crossing parentages in various breeding programs for high yield, good quality and pest resistance in China. Thus, strengthening introduction and utilization of foreign rice germplasm is significant to increase genetic-diversity and to enrich germplasm, which is also one of chinese national strategies to respond to strong competition for bio-genetic resources in the world. According to the newly changing situation, we propose the regularities, direction and ways for strengthening introduction of foreign rice germplasm suitable to China.

Abstract:Inbreeding depression has long been observed because it exists in ourselves due to consanguineous mating. Inbreeding may reduce population fitness through the expression of recessive, deleterious alleles in homozygous form. Inbreeding depression is influenced by lineage effects, mating system, environment stress and so on. Human disturbance and overexploitation are the main reasons causing population decline and consequently inbreeding depression. For species conservation and restoration, we should take inbreeding into consideration.

Abstract:Evaluation of allelopathic effect in rice germplasm is the basis of breeding for rice varieties with allelopathic characteristic, which can inhibit the growth of weeds, reduce the use of chemicals, and promote the improvement of environment. In this paper, the main progress of evaluation methods for allelopathy in rice germplasm is summarized. Achievements of the physiologicad, biochemical and genetic mechanism of allelopathy in rice germplasm are briefly reviewed. Some suggestions on research and utilization of allelopathic rice germplasm have been put forward.

Abstract:Research on the genetic relationships of Boehmeria can provide scientific basis for exploring the origin, evolution,classification and ramie breeding. In this paper,the authors summarize studies on the origin of Boehmeria and advances in the study of genetic relationships of Boehmeria using morphological, chromosomal, isozyme and DNA marker techniques. The authors also put forward the future direction.

Abstract:Studies on germplasm resources of Chinese taro ( Colocasia esculenta Schott) are reviewed in this paper, involving origin, distribution, classification, preservation, nutrition, morphology, cytobiology, molecular biology and germplasm enhancement etc.