黄淮麦区部分小麦种质资源的SSR聚类分析

利用79对SSR引物对黄淮麦区129份种质资源进行了分析。结果表明, 79对引物共检测到335个等位变异，每个引物检测到的等位变异数目2～8个，平均4.240个，变异最大的位点主要位于B组染色体上。79个SSR位点的遗传多态性信息含量在0.015～0.820之间，平均0.498。种质资源间的遗传相似系数在0.253～0.909之间，平均0.492。聚类分析把这些种质资源分为4大类和7个亚类。聚类结果与地域并不吻合，但能较好地反映出亲本的特性和其间的亲缘关系。关键词：黄淮麦区；小麦；种质资源；遗传多样性；SSR标记；聚类分析     

利用SSR分析小豆种质遗传多样性

摘要：小豆是一类重要的食用豆,本研究利用45对SSR引物对小豆基因组DNA进行了SSR标记的筛选鉴定,共筛选出多态性良好、扩增效果稳定的SSR引物18对。利用筛选出的18个SSR标记,分析了来自我国栽培小豆优异种质53份和日本引进种质27份,旨在阐明其遗传多样性特点,为育种利用提供理论依据。结果表明,在所有参试的80份小豆种质中共鉴定出等位变异92个,平均每个位点为5.1个;其中53份国内小豆和27份日本小豆的等位变异数分别为89个和74个,平均每个位点分别为4.9个和4.1个。所有供试小豆平均每个位点的多态信息含量（PIC）为0.64,变化范围为0.23～0.83,其中国内小豆的平均PIC值为0.63,变化范围为0.23~0.86;日本小豆平均PIC值为0.61,变化范围为0.20~0.81。国内栽培小豆和日本小豆在等位变异数、多态信息含量（PIC）、遗传相似性系数均存在差异,UPGMA聚类分析将参试的80份小豆明显分为五大类,聚类结果与小豆种质地理起源呈现出一定的相关性。试验表明,在小豆遗传育种中,可以通过种质资源相互利用来拓宽育成品种的遗传基础,同时这些SSR标记对于小豆资源DNA指纹图谱构建、遗传作图、基因型鉴定及分子标记辅助育种具有重要意义。     

我国部分冬小麦新品种（系）SSR标记遗传差异的研究

本研究利用53对SSR引物对全田1999－2000年北方冬麦区及黄淮冬麦区观察圃中选出的48个新品种（系）进行遗传差异研究，共检测出58个SSR位点上的367个等位变异，平均每个位点有6.33个等位变异，其中B组每个位点的等位变异最多，这表明B基因组化更快，分化更大。48个品种（系）在全基因组及A、B、D基因组聚类结果表明这些品种的相似系数聚类的范围较小，为0.75－0.98。全基因组聚类结果与品种的系谱来源及育成地区相吻合。研究结果表明我国冬小麦品种的种质基础相对较狭窄。加强不同来源种质的利用和特异亲本类型的培育对我国冬小麦遗传改良非常重要，利用5个多态性高的SSR标记就可以将这48个小麦新品种（系）区分开，每个品种（系）都有各自独特的指纹图谱。     

基于SSR标记的粗山羊草遗传多样性分析

粗山羊草(Aegliops tauschii)是普通小麦遗传改良的重要基因资源.随机选取8份粗山羊草对普通小麦的211对SSR引物进行了引物筛选.选取稳定清晰、有特异带的32对SSR引物对78份粗山羊草进行多样性分析,共扩增出308个等位位点,平均每对SSR引物扩增出8.14个等位位点,其中A组引物、B组引物和D组引物分别扩增出39个、51个和212个等位位点,平均每个组等位位点分别为5.57个、6.38个和12.47个,D组引物检测到遗传变异最丰富,说明粗山羊草D组的同源性与普通小麦的D组同源性最高,同时,能在A、B引物中扩出特异性条带,说明粗山羊草D组与普通小麦的A、B基因组也有一定的同源性.UPGMA聚类结果表明,78份粗山羊草在遗传相似系数0.77时聚为6个主要类群,而且遗传聚类关系与材料的地理来源有一定的相关性.     

浙江省和其他省份大豆种质资源的遗传多样性分析

利用47个SSR位点对90份来自浙江省和其他省份的大豆种质资源进行遗传多样性分析,结果表明：在90份材料中共检测到420个等位变异,等位变异数变化范围为3-21个,平均每个位点等位变异数为8.94个;遗传多样性指数Simpson指数分布范围为0.564-0.939,平均值为0.812,Shannon-weaver指数分布范围为0.943-2.899,平均值为1.877;成对品种间相似系数变化范围从0.5310-0.8619,总体平均值为0.6854,可见所选材料具有丰富的遗传变异。在聚类分析分析中,以相似系数为0.659为划分标准,将90材料分为两大类,Ⅰ类包括45份材料,以浙江省外的材料为主;Ⅱ类包括45份材料,以浙江省内的材料为主;SSR聚类结果与材料的地理来源和种皮色有一定的相关性。     

大蒜种质遗传多样性的SSR分析

为了探索中国大蒜种质个体的SSR位点的分布情况,为品种鉴定、保存及遗传改良提供分子生物学依据,利用6对SSR引物对40个大蒜(Allium sativumL.)品种进行聚类分析、主成分分析及遗传多样性评价。共检测到21个多态性位点,平均每对引物可扩增出约3.5条多态性片段,多态性百分率为56.76%;SSR引物组合平均有效等位基因数、Nei基因多样度和Shannon信息指数分别为1.5551、0.3414和0.5188。聚类分析显示,6对SSR引物可把40份大蒜种质资源从0.59相似系数水平上3个类群。第一类群包含28份种质,在相似系数为0.73的水平上进一步又被分成了3个亚类;第二亚类仅包含2份种质;第三亚类包含10份种质,在0.68的相似系数水平上分成了2个亚类。主成分分析和UPGMA的结果基本一致。不同地理来源的大蒜种质的Shannon-Weaver多样性指数的变幅为0.0576~0.4179,说明大蒜种质遗传多样性丰富。本研究利用SSR分子标记技术较准确地解析大蒜不同材料间的亲缘关系及遗传多样性,为中国大蒜SSR分子标记提供基础资料。     

利用SSR标记对中国柚类资源及近缘种遗传多样性研究

利用SSR标记研究了122份我国柚(CitrusgrandisOsbesk)类资源及近缘种遗传多样性。31对SSR引物从供试材料中检测出335个等位基因变异,平均每个位点可检测到9.85个等位基因。位点多态信息量(PIC)变幅为0.1939!0.9073,平均为0.7085。用UPGMA方法将122份材料分成7个组群,110个柚类品种在相似系数0.712,可细分成18个亚组,主要由沙田柚品种群、文旦柚品种群及庞大的杂种柚品种群组成。     

山东省46个花生品种SSR指纹图谱构建与遗传多样性分析

为从分子水平上快速鉴别花生品种和选配优良杂交组合,以山东省审定的46个花生品种为材料,利用微卫星(SSR)标记进行DNA指纹图谱的构建和遗传多样性分析。从788对SSR引物中筛选出50对多态性高、稳定性好、谱带清晰的引物,共检测到175个等位位点,其中122个为多态性位点,多态性比率达70.52%;每对SSR引物扩增出的等位位点数为2~7个,多态性信息量变化范围为0.6753~0.8412,平均为0.823。此外,利用14对引物可将46份材料完全区分开。聚类分析表明,在相似系数0.77处,所有供试材料聚为一类,在相似系数0.80处,仍有76%的材料聚在一起。利用SSR标记构建的指纹图谱可为花生种质资源管理及育种实践提供依据。     

黑龙江省春小麦品种遗传多样性的SSR分析

本研究利用微卫星标记(SSR)技术对黑龙江省小麦品种的遗传多样性进行了分析。12对具有多态性的SSR引物在114份小麦品种中共检测到46个等位位点,每对引物检测到的等位位点数为3~8个,平均为3.8个,平均遗传距离为0.7331。不同育种单位的小麦平均遗传距离有较大差异,最大差距为1.30倍。在对不同年代小麦品种的遗传距离分析时发现,随年代的增加,遗传距离逐渐减小,且衰减速度呈加快趋势。聚类分析将114个春小麦品种大致分为3个类群,9个亚类群,较好地反映了品种之间的亲缘关系。     

EST-SSR分析云南茶树资源的遗传多样性和亲缘关系

利用EST-SSR标记对云南134份茶树资源遗传多样性和亲缘关系进行了分析。30对引物共检测到等位位点127个,平均每对引物产生423个;共检测到263个基因型,平均每对引物所扩增的基因型有88个;遗传多态性信息含量平均达0501,高于其它地区的相关研究结果,表明云南茶树资源具有丰富的遗传多样性。资源间的平均遗传距离和相似系数分别为0413和0597,说明资源间的遗传差异比较大,遗传基础较宽。聚类可将134份资源划分为4大组。8个种群间的遗传相似系数变异范围为0753～0981,平均遗传相似系数为0891,表明不同种群间的遗传差异比较小。云南茶树资源间亲缘关系的揭示为今后茶树资源保存和新品种选育提供了一定理论依据。     

Genetic diversity and population structure of vegetable soybean (Glycine max (L.) Merr.) in China as revealed by SSR markers

Vegetable soybean is a kind of value-added specialty soybean serving as vegetable or snacks. Understanding the genetic structure of vegetable soybean is a key point for further utilization in breeding programs. In the present study, the genetic structure and diversity of 100 vegetable soybean accessions planted in China was analyzed using 53 simple sequence repeat (SSR) markers. A total of 296 alleles were detected with an average of 5.6 alleles per SSR locus. The polymorphism information content (PIC) values of SSR markers ranged from 0.074 to 0.831, with an average of 0.573. Nei’s genetic distance between accessions ranged from 0 to 0.9434 with an average of 0.6286. These vegetable soybean germplasms could be divided into 8 subgroups based on STRUCTURE analysis, or 11 subgroups based on unweighted pair group method with arithmetic average (UPGMA) cluster. Further comparison showed that the UPGMA subgroups and STRUCTURE subgroups were in fact highly consistent. Germplasms in each classified groups showed great consistency with their origins, seed coat colors or pedigrees. Genetic relationships among germplasm panels that initially came from different geographical regions were also analyzed. Germplasm panels from China Mainland, Taiwan Island and Japan were highly similar to each other with the similarities of over 98 %. Molecular data and cluster analysis also showed that germplasms from China Mainland are more diverse than those from other areas. These results gave us a deep insight into the genetic structure of vegetable soybeans in China and will help us to improve the breeding strategies.     

Simple sequence repeats marker polymorphism in emmer wheat (<Emphasis Type="Italic">Triticum dicoccon</Emphasis> Schrank): Analysis of genetic diversity and differentiation

Genetic diversity was investigated in 73 accessions of emmer wheat (Triticum dicoccon Schrank) from 11 geographical regions using a set of 29 simple-sequence repeat (SSR or microsatellite) markers, representing at least two markers for each chromosome. The SSR primers amplified a total of 357 different alleles with an average of 12.31 alleles per locus. The number of fragments detected by each primer ranged between 6 (Xgwm1066) and 21 (Xgwm268). Null alleles were detected in nine of the 29 primers used. A high level of gene diversity index was observed. Across the 29 primers, gene diversity ranged from 0.60 (Xgwm46) to 0.94 (Xgwm655), with a mean of 0.82. There was a highly significant correlation (r=0.882; p<0.01) between gene diversity index and the number of loci, showing the number of loci per se is a strong indicator of diversity. Analysis of genetic diversity within and among eleven geographical regions revealed most of the genetic diversity of the total sample resided within regions. The coefficient of gene differentiation (Gst = 0.27) showed that the genetic variation within and among the 11 geographical regions was 73 and 27%, respectively. High value of mean number of alleles per locus was found in Iran (4.86) followed by Morocco (4.10) and Armenia (4.03). On the contrary, lower mean number of alleles per locus was detected in Yemen (2.83). The average gene diversity index across regions ranged from 0.52 (Slovakia) to 0.67 (Morocco) with an average of 0.60. Multivariate techniques of principal component analysis and clustering were employed to examine genetic relationship among the 73 emmer wheat accessions vis-à-vis geographical regions of collections. The genetic distance coefficients for all possible 55 pairs of regional comparisons ranged from 0.63 (between Iran and Armenia, Georgia and Azerbaijan, Georgia and Slovakia) to 0.97 (between Morocco and Yemen, Spain and Georgia, and Turkey and Iran) with a mean of 0.82. From the PCA results, a two dimensional plot of PC1 versus PC2 was constructed. The scatter plot of the first two principal components which explained altogether 27% of the total variation depicted the presence of a clear pattern of geographical differentiation except in few cases like accessions from Caucasian region. Similar pattern of genetic relationships among accessions was observed in cluster analysis. The study provided genetic information of emmer wheat in relation to geographical regions of origin. The information could be utilized in crop improvement, germplasm conservation programs, and in further investigation.     

南瓜栽培品种的SSR分子标记分析及农艺性状多样性研究

为了研究南瓜栽培品种的遗传多样性,本研究利用43个简单序列重复(SSR)分子标记,对35份南瓜育成品种及地方品种进行了分子标记分析,并调查了农艺性状。结果表明,43个SSR标记均能扩增出多态性条带,共检测到155个等位基因,平均每个标记能检测到3.6个等位基因,多态性信息含量(PIC)为0.130 8~0.775 4,平均值为0.487 2。利用非加权组平均法(UPGMA)进行聚类分析,结果表明35份材料可分为三大类,分别与中国南瓜、印度南瓜和美洲南瓜三个种吻合,且印度南瓜与美洲南瓜之间的亲缘关系较近。农艺性状调查结果表明,不同栽培种之间以及同一栽培种内的不同品种之间,都发现有农艺性状差别明显的情况。本研究为南瓜种质资源的保护、品种指纹图谱的建立及分子育种提供了理论依据。     

Genetic Diversity Among Traditional Ethiopian Highland Maize Accessions Assessed by Simple Sequence Repeat (SSR) Markers

Over the past three centuries, maize has become adapted to complex environmental conditions in the highlands of Ethiopia. We analyzed 62 traditional Ethiopian highland maize accessions, using 20 simple sequence repeat (SSR) markers and 15 morphological traits, to assess genetic diversity and relationships among these accessions and to assess the level of correlation between phenotypic and genetic distances. The accessions varied significantly for all of the measured morphological traits. The average number of alleles per locus was 4.9. Pair-wise genetic dissimilarity coefficients ranged from 0.27 to 0.63 with a mean of 0.49. Ward minimum variance cluster analysis showed that accessions collected from the Northern agroecology were distinct from the Western and Southern agroecologies. However, there was no differentiation between the Western and Southern accessions. This suggested gene flow between these regions. The relationship between morphological and SSR-based distances was significant and positive (r = 0.43, p = 0.001). The high genetic diversity observed among these set of accessions, suggests ample opportunity for the development of improved varieties for different agroecologies of Ethiopia. From conservation perspective, sampling many accessions from all agroecologies would be an effective way of capturing genetic variation for future collections and conservation.     

Genetic relationship of diploid wheat (<Emphasis Type="Italic">Triticum</Emphasis> spp.) species assessed by SSR markers

Genetic diversity of 139 accessions of diploid Triticum species including Triticum urartu, Triticum boeoticum and Triticum monococcum was studied using 11 SSR (simple sequence repeats) markers. A total of 111 alleles with an average of 10 alleles per locus were detected. The polymorphism information content (PIC) of each SSR marker ranged from 0.30 to 0.90 with an average value of 0.62. Among the three Triticum species T. urartu had the highest number of total alleles (Na?=?81), private alleles (Npa?=?15) and showed higher genetic diversity (Hex?=?0.58; PIC?=?0.54). The genotypes from Turkey exhibited the highest genetic diversity (PIC?=?0.6), while the least diversity was observed among 4 Georgian accessions (PIC?=?0.11). Cluster analysis was able to distinguish 139 wheat accessions at the species level. The highest genetic similarity (GS) was noted between T. boeticum and T. monococcum (GS?=?0.84), and the lowest between T. urartu and T. monococcum (GS?=?0.46). The grouping pattern of the PCoA analysis corresponded with cluster analysis. No significant differences were found in clustering of T. urartu and T. monococcum accessions with respect to their geographic regions, while within T. boeoticum species, accessions from Iran were somewhat associated with their geographical origin and clustered as a close and separate group. The results from our study demonstrated that SSR markers were good enough for further genetic diversity analysis in einkorn wheat species.     

Molecular genetic diversity analysis in emmer wheat (Triticum dicoccon Schrank) from India

Emmer wheat (Triticum dicoccon Schrank) is still largely cultivated in India, and highly appreciated for the preparation of traditional dishes. Moreover, its nutritional characteristics could justify a development of its cultivation. The perspective of genetic improvement however requires a good knowledge of the genetic diversity existing within the eco-geographic group of Indian emmer wheats. A set of 48 emmer wheat accessions from India including 28 from a local collection and 20 Indian accessions obtained from CIMMYT, Mexico, was assessed for genetic variability using 47 microsatellite (SSR) markers, distributed over all the 14 chromosomes. The number of alleles per locus ranged from 2 to 9, with an average of 3.87 alleles per locus. A total of 201 alleles were detected at 52 loci with average polymorphic information content of 0.35 per locus and a mean resolving power of 1. The pair-wise similarity coefficients calculated from binary data matrix based on presence or absence of alleles varied from 0.15 to 0.98, but was greater than 0.5 for most accessions, indicating a high level of similarity. A cluster analysis based on the similarity matrix identified nine distinct accessions and three clusters. All the recently developed commercial varieties were distinctly different from the clusters. Based on the analysis, it appears that Indian emmer wheats are not very diverse. Consequently, there is a need to increase the diversity within the Indian emmer wheat eco-geographic group, by introducing diversity from other eco-geographic groups, or even from other wheat species.     

利用SSR对60个玉米自交系进行杂种优势群划分初探

用SSR对60个玉米自交系的DNA进行分子标记和杂种优势群划分研究。利用14对SSR引物在供试材料中检测出57个等位基因变异,每对引物检测等位基因2～7个,平均为4．07个,多态信息量变化范围为0．389～0．832,平均为0．692。自交系间遗传相似系数变幅为0．058～0．756,UPGMA聚类分析表明,供试自交系可分为五个类群。利用这14对具有较高多态性信息量的引物,可以对供试材料进行初步鉴定。