不同水系绒螯蟹线粒体DNA的遗传差异和群体遗传多样性研究

对中国大陆6水系10个地区中华绒鳌蟹和合浦绒螯蟹自然群体及1个俄罗斯地区日本绒鳌蟹群体中共289个个体的线粒体细胞色素氧化酶亚基I进行了RFLP分析。选用8种能识别4碱基的限制性内切酶AluI,DpnII,HaeIII,MspI,MseI,RsaI,TaqI和TasI及3种能识别6碱基的限制性内切酶ApaI,NdeI和VspI对该基因片段酶切后,在11个群体中共检测到15种复合单倍型,其中复合单倍型1为除合浦绒鳌蟹以外的群体所共有,并均以该复合单倍型为主(46.4%~96.7%),复合单倍型4在合浦绒鳌蟹群体中占有很大比例(91.7%);合浦绒螯蟹与中华绒螯蟹北方水系(黄河、海河、辽河)的遗传差异最为明显(Pnet=0.060~0.061);不同水系中华绒螯蟹及合浦绒螯蟹、日本绒螯蟹具有一定的群体内遗传多态性(π=0.000 2~0.016 7),但并不高。     

基于线粒体DNA控制区序列分析我国马鹿5个亚种的遗传分化

为了解马鹿种群遗传结构和分化水平,测定了马鹿5个亚种11个地理群共计146个体线粒体DNA控制区全序列。序列分析检测到167个变异位点,确定了54种单倍型;各个亚种呈现较高的单倍型多样性(h:0. 600～0. 959)及中等程度的核苷酸多样性(π:0. 006 3～0. 012 6)。中性检验仅发现甘肃马鹿显著性偏离中性突变,亚种间遗传分化指数FST 0. 5、基因流Nm0. 5,表明马鹿亚种间发生了显著的遗传分化,只存在少量基因交流。基于最大简约法和贝叶斯法构建的单倍型系统进化树和单倍型中介网络图显示塔里木马鹿有别于其他马鹿,它们分别来源于共同祖先的2个不同进化枝,阿尔泰马鹿、甘肃马鹿、阿拉善马鹿、天山马鹿又可细分为3个进化枝系,但它们是相互交叉聚类的。为我国马鹿的遗传资源保护和利用提供依据。     

桑树野生群体遗传多样性的分子评价

本研究分析了16个野生桑树（Morus serrata Roxb．）群体的遗传多样性，以便将其应用于栽培近缘种的渗入育种计划中。我们对印度Uttaranchal和Himachal Pradesh的不同桑树自然群体的形态一解剖性状的多样性和ISSR标记进行了研究。这些群体的形态一解剖性状和DNA标记存在显著的遗传多样性。     

瓦氏雅罗鱼群体基于 COⅠ序列的遗传多样性分析

利用mtDNA COⅠ基因片段（有效长度635 bp）对来自达里湖（DL）、岗更湖（GG）、呼伦湖（HL）、黑龙江（ HLJ）、松花江（ SHJ）和乌苏里江（ WSL）6个地理群体共72个样品进行了遗传多样性和遗传结构分析。从碱基组成来看,6个地理群体在COⅠ区段上的A＋T含量（52．37％）明显高于G＋C含量（47．67％）,符合脊椎动物的碱基组成特点;从各项遗传参数来看,达里湖流域2个群体（ DL和GG）的遗传多样性低于黑龙江流域4个群体（ HL、HLJ、SHJ、WSL）;6个群体共检测到20个单倍型,并共享1个单倍型,达里湖流域群体共享1个单倍型,黑龙江流域群体共享1个单倍型。虽然达里湖流域和黑龙江流域各群体间遗传分化明显（ P＜0．05）,遗传结构存在差异,但AMOVA检验不支持这种遗传差异;另外,群体间频繁的基因交流进一步证实,6个地理群体亲缘关系近,有共同的起源,尚未达到分化为不同的种或亚种的水平。     

栽培与野生大麦籽粒性状比较及群体遗传多样性分析

为了解大麦群体遗传多样性,指导大麦育种亲本组配,对137份栽培与野生大麦籽粒性状差异进行比较,结合皮裸、棱型特征,估算各品种间遗传相似系数(GS),对群体进行聚类分析。结果表明,栽培大麦粒长(8.16 cm)显著短于野生大麦粒长(13.19 cm),但其粒宽与粒厚(3.33 cm与2.62 cm)相对于野生大麦(2.92 cm与1.69 cm)显著增加,粒重在两者间差异不显著。大麦籽粒性状变异可能与品种选育中增加穗粒数及改良品质目标有关。群体遗传多样性分析表明,遗传相似系数(GS)变幅为0~0.5,平均值为0.34,在0.334水平上将参试材料聚为4类。第Ⅰ类为六棱皮大麦(35份),主要为饲用,来源地为我国中东部地区;第Ⅱ类为六棱裸大麦(47份),主要为食用,来自青藏高原一带;第Ⅲ类是二棱皮大麦(51份),包括啤用大麦(来自我国)与野生大麦(来自以色列);第Ⅳ类是二棱裸大麦(4份),其中1份来自湖北,其他3份来源地不明确。聚类结果与棱型、皮裸特征分类一致,与来源地无明显相关性,但在一定程度上表现与大麦用途相关。大麦群体遗传多样性丰富,在育种实践中利用野生大麦资源时,建议将其与遗传距离相对较近的栽培二棱皮大麦进行组配,有利于优良基因位点纯合,提高育种效率。     

基于SNP标记的大麦遗传多样性与群体遗传结构分析

为了评价大麦种质组合的配制,本研究对384份不同来源大麦种质资源的农艺性状和遗传背景进行分析,并选取了分布于大麦7条染色体上具有多态性的6 454个SNP标记进行群体遗传结构分析,结果表明:(1) 384份参试大麦种质资源的6个农艺性状中,除分蘖数外,其他性状表现基本接近正态分布。6个参试农艺性状统计量指标在环境、基因型、基因型与环境互作效应方面均达到极显著水平(p<0.01)。(2) SNP标记基因分型共分为8种类型。其中A/G类型的最多为2 386个;T/A类型的最少,为104个。平均各条染色体上分布922个,其中4H染色体上最多,为1 288个;1H染色体最少,为642个。(3)遗传结构分析结果显示,384份参试材料分为3个亚群,第1亚群有48份材料,第2亚群有149份材料,第3亚群有187份材料。本研究结果为分子标记辅助育种提供科学依据。     

野生榆叶梅遗传多样性的AFLP分析

本研究利用AFLP分子标记技术,对野生榆叶梅6个居群进行分析.利用已筛选出的8对引物组合进行扩增,共产生256条谱带,其中206条谱带具有遗传多态性,占总谱带的80.47％;平均每对引物组合扩增产生129条多态条带,平均多态率为50.26％.6个居群观察等位基因数Na平均值为1.502 6,总Na值为1.804 7;有...     

应用mtDNA Cytb基因全序列分析中国5个马鹿群体的遗传多样性和系统发育

为了在分子水平上探讨马鹿的遗传多样性和系统发育,对我国5个马鹿群体43头马鹿mtDNA Cytb基因全序列进行了分析。结果表明:5个马鹿群体mtDNA Cytb基因全序列中A、T、G、C含量没有明显差别;多态位点占分析位点的7.63%,天山马鹿和塔里木马鹿的单倍型比例分别为100%,50%,单倍型多样度(Hd)分别为(1.000±0.218),(0.700±0.096),核苷酸多样度(Pi)分别为0.00333,0.00544,平均核苷酸差异数值(K)分别为3.800,6.200,其遗传多样性较丰富。对13个马鹿单倍型序列的系统发生分析表明,我国马鹿有2个母系起源。从GenBank获得33个马鹿Cytb基因全序列与本研究的马鹿Cytb基因的单倍型进行网络关系分析,发现塔里木马鹿与西方马鹿群体具有较近的亲缘关系。     

基于SSR标记的华南野生蓖麻遗传多样性分析

国内外研究表明蓖麻是一个遗传多样性很低的物种,利用野生材料拓宽遗传基础对蓖麻育种至关重要。本研究用72对多态性SSR标记对从广东、广西和海南三省(区)收集的240份野生蓖麻材料进行了的遗传多样性分析。结果表明,平均每个SSR位点检测到等位基因4.819个、有效等位基因2.410个,平均多态性信息含量(PIC)为0.481,平均Shannon's信息指数(I)为1.007,平均期望杂合度(He)为0.525,均高于以往报道结果。按地理来源分析,来自广东的材料遗传多样性最高,广西的次之,海南的最低。群体遗传结构分析将240份材料划分为3个类群,每个类群遗传背景独特,与地理分布基本一致,类群间存在一定程度的基因交流。聚类分析在遗传相似系数为0.404时,将240份材料分为4个组,组间亲缘关系与地理分布没有直接联系,但随着遗传相似系数的增大,同一地区的材料有聚到一起的趋势。以上结果证明中国华南野生蓖麻材料遗传多样性较为丰富,是比较独特的一类蓖麻种质资源,应进一步加强保护、研究和利用。本研究对华南野生蓖麻的高效保护和研究利用提供了数据参考。     

基于SSR标记的贵州野生白三叶遗传多样性分析

采用SSR分子标记技术,对贵州22份野生白三叶(Trifolium repens)样品遗传多样性及亲缘关系进行了研究.结果表明,利用20对SSR引物共扩增出202条带,其中169条带具有多态性,多态性位点达83％;根据SSR标记的多态性计算不同采样地野生白三叶样品之间的遗传距离(GD),22份样品之间遗传距离介于0.140 6～0.630 4之间,说明样品间遗传差异较大;聚类分析结果,当相似系数为0.64时,22份白三叶被分成3类:第1类只有W14,表明W14与其余材料的亲缘关系较远;第2类包括W2、W4、W8、W18居群,表明这4个居群相似性较大,遗传距离较近;第3类包括17个居群,居群间有着复杂的遗传关系.研究结果表明,22份贵州野生白三叶的遗传多样性十分丰富.     

Genetic diversity for RAPD markers between cultivated and wild accessions of Coffea arabica

Summary Random amplified polymorphic DNA (RAPD) markers have been successfully employed to analyse the genetic diversity among cultivated and subspontaneous accessions of Coffea arabica. The narrow genetic base of commercial cultivars was confirmed. On the other hand, a relatively large genetic diversity was observed within the germplasm collection demonstrating the importance of collecting missions. Results suggested an East-West differentiation in Ethiopia, the primary centre of diversification of C. arabica. The large heterosis effect reported in intergroup hybrids could be related to such genetic differentiation. RAPD method appeared to be effective in resolving genetic variations and in grouping germplasm in C. arabica.     

糯玉米自交系SSR标记遗传多样性及群体遗传结构分析

为了解糯玉米种质的遗传基础,利用29对SSR标记对87份糯玉米自交系进行遗传多样性分析,共检测出180个等位变异,平均每个位点6个等位变异,多态性信息含量变幅为0.308～0.915,平均为0.572。材料间遗传相似系数为0.49～0.93,平均为0.66。通过聚类分析UPGMA (unweighted pair-group method with arithmetic means)方法在遗传相似系数0.64处将87份糯玉米自交系划分为4个类群,分别包含9、66、10和2份材料。此外,利用Structure群体遗传结构分析也将87份糯玉米自交系分为4个类群,分别包含24、25、19和19份材料;进一步分析表明,供试群体中大部分糯玉米自交系的遗传变异较单一。本研究为糯玉米新品种选育和遗传进化分析提供了种质基础和理论依据。     

Genetic diversity in Cynara cardunculus revealed by AFLP markers: comparison between cultivars and wild types from Sicily*

Genetic diversity in 49 plants of 16 accessions representing one wild and two cultivated taxa of Cynara cardunculus L. (wild cardoon, cultivated cardoon and globe artichoke) was investigated using amplified fragment length polymorphic (AFLP) analysis. Four pairs of primers identified a total of 264 scorable loci, 196 of which were polymorphic. The number of markers scored per primer combination ranged from 41 to 107, with an average of 66 markers per primer combination. All the primer combinations detected polymorphism. The data were used for cluster analysis and AMOVA. The clusters obtained are in agreement with the current botanical classification and the differences among the taxa were substantial. The eco‐geographical groups within wild cardoon are clearly separated in relative subclusters, and reflect the geography of the collection areas. The six clones of the four cultivated artichoke varieties were clearly separated into four subclusters, corresponding to the current classification which is based on morphological traits. The results obtained may have a direct and important bearing on plant genetic resource conservation and management and on breeding.     

基于SNP和InDel标记的巴西木薯遗传多样性与群体遗传结构分析

为了对巴西木薯种质资源进行遗传多样性、亲缘关系和群体遗传结构分析,本研究利用了7946个SNPs和1997个InDels分子标记,通过ADMIXTURE软件进行群体结构分析、GCTA软件进行主成分分析。结果显示,巴西木薯被划分为9个亚群。这与利用PHYLIP进行的聚类分析结果大概一致,其中亚群1、亚群2、亚群4、亚群6和亚群8能较好地分别聚在一起,而其他亚群中的样品大致能聚在一起,且样品间有一定的交叉。巴西木薯种质资源遗传多样性指数(0.274)高于中国、尼日利亚等,其中巴西木薯亚群5具有相对较高的遗传多样性水平(0.29)。巴西木薯各亚群的群体遗传分化程度较低(群体分化指数在0.03~0.15之间),但高于中国木薯种质资源的群体分化指数。各木薯材料间的遗传距离变幅为0.084~0.297,平均遗传距离为0.228。本研究结果可为后续关联分析发掘优良等位基因及引种提供依据。     

基于SNP和InDel标记的巴西木薯遗传多样性与群体遗传结构分析

As a typical tropical crop, cassava (Manihot esculenta Crantz) has the characteristics of drought resistance, barren resistance, high biomass and so on. In addition to being used for food and forage, it can also be used for production, processing and starch extraction. Due to highly heterozygous cassava genome, breeding is more difficult. Enriching the genetic diversity of cassava germplasm, comprehensively evaluating its genetic background and traits, and discovering superior alleles that control excellent traits are of great significance for cassava breeding in the future. In order to analyze the genetic diversity, genetic relationship and population structure of cassava germplasm in Brazil, 7946 SNPs and 1997 InDels molecular markers were used. Population structure analysis was performed by ADMIXTURE software, and principal component analysis was performed by GCTA software. Brazilian cassava was divided into nine subgroups, and was roughly consistent with the results of cluster analysis using PHYLIP. Among them, subgroup 1, subgroup 2, subgroup 4, subgroup 6, and subgroup 8 could be clustered together respectively, while the samples of other subgroups could be roughly clustered, and there was a certain cross between the samples. The genetic diversity of cassava germplasm in Brazil (0.274) was higher than the genetic diversity level of cassava germplasm in China and Nigeria. Subgroup 5 of Brazil cassava had a relatively high genetic diversity (0.29). The genetic differentiation of subgroups was low (the genetic differentiation vary from 0.03 to 0.15), but higher than domestic cassava germplasm. The genetic distance between cassava accessions varied from 0.084 to 0.297, with the average of 0.228. The results of this study can provide a basis for subsequent association analysis to identify great alleles and introduction.     

基于形态学性状和SSR标记的花生品种遗传多样性分析和特异性鉴定

以101份南方花生区试品种为材料,利用形态学性状和SSR标记进行品种遗传多样性分析和特异性鉴定。结果表明, 29个形态学性状中有7个无多样性,其余22个的多样性指数为0.23～0.77,平均为0.43。在相似系数为0.76处,将供试品种划分为七大类群,同一育种单位的品种倾向于聚在一起。用40个SSR标记共检测出167个等位基因,单个标记检测的等位基因数2～6个,平均为4.18个。标记的多态性信息量(PIC)差异较大,最大为0.79,最小为0.26,平均为0.55。在相似系数为0.70处,供试品种可被划分为六大类群,同一省份育成的品种多聚为一类。Mantel检验发现品种间的形态学性状和SSR标记的相似系数矩阵相关性弱(r=0.36),SSR标记无法取代形态学性状单独用于花生品种特异性鉴定,但两者相结合能有效提高花生品种特异性鉴定的准确性。     

A genetic diversity analysis of wild Lespedeza populations based on morphological characters, allozyme and RAPD methods

Genetic variability within and among 14 Chinese natural populations of Lespedeza Michx. Used mainly for wildlife food and cover and for erosion control was evaluated on the basis of morphological characteristics, allozyme markers and random amplified polymorphic DNAs (RAPDs). All methods disclosed a high degree of allelic heterogeneity among samples, also revealing a high degree of gene diversity. Genetic variation among populations was higher for RAPD than for enzyme loci. Correlation between morphological, allozyme and RAPD distance matrices were calculated by Mantel’ tests. There was a little disparity between the three level's distances on population relationships. However, there is a weak significant correlation (P < 0.001) between morphology and allozyme distances as well as morphology and RAPD distances, and the test of this correlation is very high.     

Genetic diversity and differentiation of Chinese wild soybean germplasm (G. soja Sieb. & Zucc.) in geographical scale revealed by SSR markers

Wild soybean (Glycine soja), as the progenitor of soybeans (G. max), is widely distributed in China and has been collected as a supplementary germplasm pool of soybeans. In this study, 375 wild soybean accessions from a set of genebank core collection were analysed for genetic diversity by using 42 simple sequence repeat primer pairs. The mean allele number per locus was 19.62. Ten‐percent unique alleles involving 35 or 83.33% loci differentiated among the geographical regions. The mean gene diversity (h) per locus was 0.89. A very low mean coefficient of gene differentiation (G_ST = 0.08) for geographical regions and a high mean within‐region gene diversity (H_S = 0.81) were observed, indicating that most genetic diversity existed within the regions. There was an obvious relationship between genetic distance and geographical distance. The results showed multiple centers of genetic diversity for Chinese wild soybean in North China, the Huanghe River Valley, and Central China as well as the Changjiang River Valley, implicating multiple site origins of soybeans within China.     

新疆冬小麦品种农艺及产量性状遗传多样性分析

Grain yield is one of the most important goals in wheat breeding, and agronomic or yield-related traits can directly reflect the characteristics of varieties. In order to determine the evolution of genetic diversity in agronomic traits of Xinjiang winter wheat varieties and their adaptabilities to different ecological environments, 134 winter wheat landraces and 54 moderns bred varieties from Xinjiang were selected for agronomic trait investigation. They were planted in three different ecological environments (Urumqi and Yining in Xinjiang province, and Tai’an in Shandong province) for two consecutive growth seasons, and nine agronomic and yield-related traits were surveyed and analyzed. The estimated broad sense heritability of nine agronomic and yield traits was in descending order: plant height > grain width > grain length/width ratio > spike length > spikelet number > thousand- kernel weight > grain number per spike > grain length > fertile spikelet number. Correlation analyses of nine agronomic and yield traits showed that these traits were correlated with each other. It was found that the plant height, spike length and grain length/width ratio of landraces were higher than that in modern bred varieties, but the grain number per spike, thousand kernel weight, grain length and grain width in landraces were less than that in modern bred varieties. However, the correlation coefficient of these nine traits was higher in modern bred varieties than that in landraces. These variations reflected the evolution of Xinjiang winter wheat varieties in agronomic traits in recent years. This study may provide important information for breeders to select the breeding parents in different winter wheat regions.     

2个群体秀丽白虾生物学特征及基于RAPD的遗传多样性研究

对太湖和巢湖2个群体秀丽白虾的生物学特征和基于RAPD的遗传多样性进行了研究。结果表明,6月份太湖秀丽白虾的体长优势组为40-50mm（占样本数的69.3%）,体重优势组为0.5-2.0g（占样本数的83.4%）,体长（L/mm）、体重(W/g)的关系式为：W=2.6E-05L2.8777;6月份巢湖秀丽白虾的体长优势组为45-55mm（占样本数的73.8%）,体重优势组为1.5-2.5g（占样本数的69.0%）,体长（L/mm）、体重(W/g)的关系式为：W=2.8E-05L2.8471。15个随机引物的RAPD研究结果表明,太湖群体多态位点比例为49.16%,巢湖群体多态位点比例为48.78%;太湖、巢湖2个群体内遗传相似系数分别为0.8817和0.8735, 2个群体之间的遗传距离为0.0311,群体间没有发生明显的遗传分化。