Genetic Relationship Analysis of Ramie Accessions by RAPD Markers

Genetic relationship of 12 ramie varieties with different drought resistance was analysed by using RAPDI Twenty-five 10- mer random primers were used to amplify the total DNA of these varieties. The results ahowed that the amplified products of 12 ramie varieties could be obtained with 12 primers. The length of amplified products was 0.6- 5.15 kb. Ninety bands were identified in total, of which 11 bands were common in all 12 varieties and 79 bands were polymorphic. The polymorphic bands were 87.78% of the total amplified bands. According to the result of cluster analysis, 12 ramie varieties could be divided into two classes and three groups. It was found that high drought resistant varieties were clustered into different groups or subgroups in the same class, which shows near relationship among them.     

Effect of Planting Density and Fertilizer Application on Fiber Yield of Ramie （ Boehmeria nivea ）

As the most important cultural practices for ramie (Boehmeria nivea) production,the single effects of plant density and nitrogen (N),phosphorus (P),potassium (K) fertilization on yield are well documen...     

Genetic Diversity Analysis of Faba Bean （Vicia faba L.） Based on EST-SSR Markers

Faba bean (Viciafaba L.), one of the most important legumes in the world, evolved different types of cultivars due to its partial cross-pollination. The development of simple sequence repeat (SSR) markers from expressed sequence tags (EST) provided a useful tool for investigation of its genetic diversity. The purpose of the present study was to investigate the genetic diversity of faba bean from China and Europe using EST-SSR markers. 5 031 faba bean ESTs from the NCBI database were downloaded and assembled into 1148 unigenes. A total of 107 microsatellites in 96 unigenes were identified, indicating that merely 8.36% of sequences contained SSRs. The most abundant SSR within faba bean was tri-nucleotide repeat motif, and among all the tri-nucleotide repeats, the motif AAG/CTT was the most abundant type. Based on these results, 11 EST-SSR markers were used to assess the genetic diversity of 29 faba bean cultivars from China and Europe with two to three alleles per locus. The polymorphism information content value ranged from 0.0644 to 0.4278 with an average of 0.2919. Principal coordinate analysis (PCA) and phylogenetic clustering based on these 11 EST-SSR markers distinguished these cultivars into different groups. The results indicated that faba bean in China had a narrow genetic basis, and the additional sources of genetic cultivars/accessions should be introduced to enhance the genetic variability. The results of this study proved that the EST-SSR marker is very effective in evaluation of faba bean germplasm.     

A Genetic Linkage Map of Kenaf （Hibiscus cannabinus L.） Based on SRAP,ISSR and RAPD Markers

Kenaf (Hibiscus cannabinus L.) is one of the most economically important crops for non-wood fiber production. The objective of this study was to establish a genetic linkage map of kenaf with higher density of molecular markers. A semi-wild variety Ga42 and a cultivar Alain kenaf were used as parents to construct an F₂ population consisting of 155 plants. The genetic linkage map comprising 134 marker loci was constructed, including 65 sequence-related amplified polymorphism (SRAP), 56 inter-simple sequence repeat (ISSR), and 13 randomly amplified polymorphic DNA (RAPD) markers. This map spans 2 108.9 cM and contains 20 linkage groups with an average marker density of 15.7 cM between the adjacent markers.     

Genetic Diversity Analysis of PVY Resistant Potato Varieties （Clones） by RAPD Markers

DNA fingerprints of 37 PVY resistant potato varieties (clones) were generated using PCR-based RAPD analysis. All 37 varieties were differentiated by banding patterns obtained from 17 primers that generated 164 polymorphisms. Similarity matrices were calculated with the simple matching coefficient. The genetic distance value among them was between 0.27 and 0.50, with average value being 0.35. The average link clustering algorithm was used to construct a dendrogram with Statistica. They were classified into three groups according to clustering results, and the results presented some geographic relationship. Dendrogram showed close genetic relationships between a number of varieties (clones) of similar pedigree. This study has shown that RAPD marker is a useful tool for potato variety identification, differentiation, and estimation of genetic relationships.     

Construction of Genetic Linkage Map Based on SSR Markers in Peanut （Arachis hypogaea L.）

Molecular genetic maps of crop species can be used in a variety of ways in breeding and genomic research such as identification and mapping of genes and quantitative trait loci （QTLs） for morphological, physiological and economic traits of crop species. However, a comprehensive genetic linkage map for cultivated peanut has not yet been developed due to the extremely low frequency of DNA polymorphism in cultivated peanut. In this study, 142 recombinant inbred lines （RILs） derived from a cross between Yueyou 13 and Zhenzhuhei were used as mapping population in peanut （Arachis hypogaea L.）. A total 652 pairs of genomic-SSR primer and 392 pairs of EST-SSR primer were used to detect the polymorphisms between the two parents. 141 SSR primer pairs, 127 genomic-SSR and 14 EST-SSR ones, which can be used to detect polymorphisms between the two parents, were selected to analyze the RILs population. Thus, a linkage genetic map which consists of 131 SSR loci in 20 linkage groups, with a coverage of 679 cM and an average of 6.12 cM of inter-maker distance was constructed. The putative functions of 12 EST-SSR markers located on the map were analyzed. Eleven showed homology to gene sequences deposited in GenBank. This is the first report of construction of a comprehensive genetic map with SSR markers in peanut （Arachis hypogaea L.）. The map presented here will provide a genetic framework for mapping the qualitative and quantitative trait in peanut.     

Genetic Analysis of Embryo, Cytoplasm and Maternal Effects and Their Environment Interactions for Isoflavone Content in Soybean [Glycine max （L.） Merr.]

Soybean seed products contain isoflavones （genistein, daidzein, and glycitein） that display biological effects when ingested by humans and animals. These effects are species, dose and age dependent. Therefore, the content and quality of isoflavones in soybeans is a key factor to the biological effect. Our objective was to identify the genetic effects that underlie the isoflavone content in soybean seeds. A genetic model for quantitative traits of seeds in diploid plants was applied to estimate the genetic main effects and genotype x environment （GE） interaction effects for the isoflavone content （IC） of soybean seeds by using two years experimental data with an incomplete diallel mating design of six parents. Results showed that the IC of soybean seeds was simultaneously controlled by the genetic effects of maternal, embryo, and cytoplasm, of which maternal genetic effects were most important, followed by embryo and cytoplasmic genetic effects. The main effects of different genetic systems on IC trait were more important than environment interaction effects. The strong dominance effects on isoflavone from residual was made easily by environment conditions. Therefore, the improvement of the IC of soybean seeds would be more efficient when selection is based on maternal plants than that on the single seed. Maternal heritability （65.73%） was most important for IC, followed by embryo heritability （25.87%） and cytoplasmic heritability （8.39%）. Based on predicated genetic effects, Yudou 29 and Zheng 90007 were better than other parents for increasing IC in the progeny and improving the quality of soybean, The significant effects of maternal and embryo dominance effects in variance show that the embryo heterosis and maternal heterosis are existent and uninfluenced by environment interaction effects.     

Genetic Relation Analysis on Ramie [Boehmeria nivea (L.) Gaud.] Inbred Lines by SRAP Markers

The objective of this article is to reveal the variations of ramie inbred lines in DNA level and discuss their molecular background to provide a theoretical basis for ramie cross breeding. In the present study, the genetic relationships among 33 inbred line accessions and two wild types that originated from China and Brazil were estimated using sequence-related amplified polymorphism (SRAP) markers. The results showed that 33 out of 81 primer combinations turned out to be polymorphic and 332 polymorphism bands were obtained. On the basis of the appearance of the markers, the genetic relationships were analyzed using unweighted pair-group method of arithmetic average cluster analysis (UPGMA), and the genetic Jaccard similarity coefficients were calculated. The inbred-lines originating from China and Brazil formed a cluster suggesting a possibility that the Brazilian cultivars could have developed from cultivars introduced from China. Within ramie inbred-lines, the groupings also indicated that the greatest genetic relationship among cultivars was correlated to the region of origin of cultivars. The results provided the evidence that SRAP was an efficient approach, suitable for taxonomic analysis of ramie inbred lines. To the authors' knowledge, this is the first application of SRAP marker on the systematics of ramie inbred lines.     

几个常用玉米自交系的优势类群分析

通过完全双列杂交设计，利用杂种优势距离对１０个常用玉米自交系进行了聚类分析。结果表明，１０个自交系可划分为以下几个类群，即｛４７８，５００３，８１１２｝类群；｛Ｅ２８，中黄６４｝类群；｛Ｍ０１７，８１５１５，抗旱大粒黄｝类群和｛５３，综３１｝类群。最强的杂种优势模式在｛５３，综３１｝类与｛Ｅ２８，中黄６４｝类之间，其次在｛４７８，５００３，８１１２｝类与｛５３，综３１｝类以及与｛Ｅ２８，中黄６４｝之间。而｛Ｍ０１７，８１５１５、抗旱大粒黄｝类与｛Ｅ２８，中黄６４｝类以及与｛４７８，５００３，８１１２｝类间优势最弱。     

48份玉米自交系的SSR遗传多样性分析

利用SSR标记对48个黑龙江省玉米自交系进行遗传多样性分析,初步进行了杂种优势群划分。从100对SSR引物中筛选取20对扩增带清晰且具有稳定多态性的引物。结果表明:20对引物在供试材料中共检测出105个等位基因变异,平均每对引物检测到等位基因数位5.25个,变化范围在3~7个,多态性信息含量变化范围为0.405~0.793,平均多态性信息量为0.664。48个自交系之间的遗传相似系数变化范围为0.400~0.905。UPGMA聚类分析结果表明:供试自交系被划分为5大类群,聚类结果与系谱分析基本一致。因此,SSR标记可以进行玉米自交系遗传变异分析,并用于杂种优势群的划分。     

54份甜玉米自交系的SSR遗传多样性分析

利用SSR标记对54份甜玉米自交系进行了遗传多样性分析,从150对引物中筛选出了56对扩增条带清晰、稳定性好的引物.结果表明:56对引物在54份甜玉米自交系中共检测到155个位点的等位基因变异,平均每对引物检测出的等位基因变异为2.77个,变异范围为2～5个,平均多态性信息含量为0.42,变异范围为0.13～0.71.UPGMA聚类结果表明,可将甜玉米自交系划分为三大类,其划分结果与系谱分析基本一致.     

鸭茅杂交种SRAP分子标记鉴定及遗传分析

【目的】利用分子标记技术对鸭茅杂交种进行快速鉴定和遗传分析,建立鸭茅杂交种的快速鉴定体系,揭示鸭茅杂交种群体遗传信息,为鸭茅资源保护利用及新品种选育提供科学依据。【方法】利用SRAP标记技术对140个鸭茅杂交种单株及其亲本(01996、YA02-103)DNA进行扩增,分析杂交种与其亲本间扩增谱带的多态性,以鉴别真假杂交种,并结合形态标记对杂交后代的遗传变异进行分析。【结果】从192对SRAP引物中筛选出64对引物在杂交种和双亲间存在扩增多态性,多态性百分比为33.33%。利用能扩增出父本特征带的引物鉴定了140个杂交种,其中106个具有父本的特征带,可鉴定为真杂交种。选择16对多态性引物对亲本和106个真杂交种进行扩增,获得151条条带,其中多态性条带71条,平均每对引物扩增出4条多态性条带,多态性位点百分比为47.24%。【结论】SRAP用于鸭茅杂交种鉴定及多态性分析是可行的。     

宁夏常用玉米自交系的SSR遗传分析

[目的]对宁夏常用的82份玉米（Zea may L.）自交系进行遗传分析,划分自交系类群,以提高玉米育种效率。[方法]利用SSR标记中可用于遗传多样性分析的20对SSR引物对材料进行分析。[结果]82份自交系中共检测出335个等位基因,其中具有多态性的为108个,每对引物检测出3～10个多态性位点,平均为5.4个。SSR引物的多态性信息量（PIC）介于0.523 3～0.858 9,平均为0.7123。[结论]82份自交系划分为5个类群,分类结果基本与系谱来源一致。     

茄子种质资源SRAP、SSR遗传多样性研究

利用SRAP和SSR技术对42份茄子材料进行了分子鉴定,开展了SRAP和SSR标记分析,12对SRAP引物获得244条特征带,13对SSR引物获得62对特征带,共计306条特征带。聚类结果显示:茄子的遗传多样性丰富,聚类结果与果实性状存在一定的相关性,但整个聚类图呈现茄子基因互相渗透现象,单基因特性和茄子的表型不能完全对应,说明茄子资源在常年自然选择过程中基因聚合发挥作用比较普遍。     

利用SSR核心引物分析257份玉米自交系遗传多样性

为简化杂种优势类群划分,加快育种进程,利用64对SSR核心引物对257份玉米自交系进行遗传多样性分析。结果表明:共检测出422个等位基因变异,每对引物检测出3～9个等位基因,平均6.59个。每个位点的多态性信息量(PIC)为0.444～0.879,平均0.769。257份自交系之间的遗传相似系数变化范围0.036～0.943。按UPGMA类平均方法进行聚类分析,供试自交系可划分为4大类群,6个亚群(Lancaster、旅大红骨、塘四平头、BSSS、PA和PB)。聚类结果与系谱基本一致。     

SRAP/RSAP标记鉴定印度南瓜种子纯度的方法

应用相关序列扩增多态性(SRAP)标记和限制性位点扩增多态性(RSAP)标记对印度南瓜品种杂交种子纯度进行鉴定试验。结果表明,筛选出的引物E1M5和R1R7可很好地区分出红栗二号、红栗、锦栗二号和锦栗南瓜,利用RSAP分子标记R1R7可检测出锦栗杂交种子纯度,分子标记检测结果与田间检测结果吻合率达到90%。