利用SSR标记分析橡胶草种质资源的遗传多样性

为了解橡胶草种质的遗传背景和遗传多样性,为今后橡胶草育种提供理论依据。利用23对SSR引物对96份橡胶草材料进行遗传多样性分析。结果显示,23对SSR引物通过扩增得到71个等位变异,等位变异范围2-6个,平均等位基因数为3.09个。通过聚类分析,俄罗斯材料和美国材料与新疆7个居群材料被分为2大类群,类群I包含所有俄罗斯和美国材料以及5份新疆野生材料,类群II包含其余新疆7个居群的材料;俄罗斯和美国材料同属于亚群A,平均遗传相似度为0.88,说明它们存在紧密的亲缘关系;新疆7个居群的材料被分为5个亚群,显示丰富的遗传多样性,而且相互之间存在复杂的遗传关系。本研究结果证明了SSR标记能够有效地用于橡胶草的遗传多样性研究,为以后的橡胶草种质收集和遗传育种提供重要依据。     

Genetic structure and differentiation in hop (Humulus lupulus L.) as inferred from microsatellites

A set of 67 wild and cultivated hop accessions, representative of hop diversity, was genotyped with 29 SSR markers in order to investigate the population structure and genetic diversity among hop genotypes. A total of 314 alleles was detected, with an average of 10.8 alleles per locus and an average PIC content of 0.607. Model-based clustering placed the accessions into five germplasm groups. A distance-based tree showed good agreement with five germplasm groups, and additionally assigned accessions omitted from model-based analysis into two additional germplasm groups. The 67 hop accessions were thus subdivided in seven germplasm groups, with three corresponding to major breeding groups and four to wild hops. This finding is in accordance with two biogeographically separated hop germplasms (European and North American origin) and with the known history of the accessions. North American hop germplasm was partitioned into native and cultivated germplasm groups. European germplasm was divided into two groups of hop cultivars representing distinguishable European germplasms and three new groups of native hops, which were differentiated for the first time by this analysis. Admixture analysis showed shares of various ancestries in hop cultivars, mostly congruent with pedigree data, and the introgression of various ancestries in some native hops. The above results have so far given the most detailed insight to date into the population structure of hop diversity, which is important for its effective use in hop breeding.     

宁夏粳稻种质资源表型性状遗传多样性分析

为了解宁夏水稻种质资源遗传多样性水平,对宁夏60份粳稻种质资源材料的16个表型性状进行遗传多样性分析。结果表明,60份宁夏水稻种质资源材料16个表型性状间存在极显著的遗传差异,其中株高、每穗总粒数、每穗实粒数、经济系数、结实率、秆长这6个表型性状的变异幅度大,方差和标准差较高,具有较大的离散程度;每穗总粒数、每穗实粒数、着粒密度、单株穗数、单穗粒重的变异系数均在14%以上,F测验表明16个表型性状的差异都达到了极显著水平;遗传相关分析表明,不同表型性状间存在显著、极显著相关关系,有些性状间为正相关关系,而有些性状间则为负相关关系,各表型性状间呈复杂的相互关系;遗传多样性分析表明,表型遗传多样性指数变幅为1.644~2.092,平均为1.957;以卡方距离按UPGMA法聚类,在遗传相关系数为0.11处可分为8类,其中‘杨和白皮稻’、‘抚105’、‘田丰302’和‘花86’各为一类,其他引进和宁夏自育的水稻品种分别聚在第Ⅳ、Ⅴ、Ⅵ、Ⅷ类,而57%的种质资源材料都聚在了第Ⅵ类,并且第Ⅳ、Ⅴ、Ⅵ、Ⅶ、Ⅷ类在相似系数为0.18处可聚成一大类,亲缘关系很近。‘杨和白皮稻’是宁夏的1个地方品种,与其他种质间亲缘关系最远。研究表明,宁夏粳稻种质资源材料间遗传差异较小,遗传背景比较单一,亲缘关系较近。     

25份贵州镇宁野生茶树种质资源的表型及生化组分多样性分析

为了挖掘特异茶树种质资源,以贵州镇宁新发现的25株野生茶树资源为材料,对26个表型性状和12个主要生化组分运用统计分析、遗传多样性分析和聚类分析等方法进行研究,进而对这25份资源进行综合评价。 结果表明这25份种质的表型性状和生化组分变异类型丰富,其中26个表型性状的平均变异系数29.26%,平均多样性指数0.87;12个生化组分性状的平均变异系数25.21%,平均多样性指数2.78;25份种质资源的酚氨比在6.12~20.09之间。聚类分析将其分为三个类群,其中类群一全部为小乔木,类群二、三全为灌木;类群三中资源的生化组分含量最为丰富。从中初步筛选出了3份生化组分丰富的潜在优异种质资源,为后续资源保护、开发和育种应用提供依据。     

国内外陆地棉品种资源的亲缘关系和遗传多态性研究

 应用SSR分子标记对国内外74份棉花种质资源的遗传多样性进行分析,从2278条SSR引物中筛选出82条引物,这82条引物共扩增出个435条带,其中多态性带313个,多态率达83.70%,平均每条引物扩增出3.81个条带。UPGMA聚类分析结果表明,74份材料的相似性系数(GS)变化范围在0.371～0.958。其中国内品种遗传相似系数变化范围在0.684～0.916,平均遗传相似系数大小顺序为：长江流域棉区品种>特早熟棉区品种>短季棉品种>黄河流域棉区品种>新疆品种。国外品种遗传相似系数变化范围为0.661～0.958,平均遗传相似系数大小顺序为：乌兹别克斯坦品种>法国品种>墨西哥和前苏联品种>美国和巴基斯坦品种>乌干达品种>印度品种>澳大利亚品种。聚类图0.760阈值处可以把国内外品种聚为两类,26个国内品种和1个国外品种被聚为国内品种类,包括3个亚类。绝大多数国外品种为一类,包括4个亚类。本研究结果表明,SSR具有丰富遗传多样性和稳定性,是一种较好的遗传分子标记,适宜于棉花品种遗传多样性分析。     

表型与分子标记相结合分析130份糖用甜菜种质的遗传多样性

旨在对甜菜种质进行比较系统的遗传多样性分析与遗传距离分析。将表型与分子标记相结合,从3 个角度分析了130 份甜菜种质的遗传多样性,并对种质进行了遗传距离的分析。130 份甜菜种质表现出比较丰富的遗传多样性,其中22 项描述性性状的多样性指数在0.0451~1.1867 之间,平均值为0.8559;23 项数值型性状的变异系数在2.94%~594.84%之间,平均值为59.10%;34 个SSR标记的多态性信息含量在0.1289~0.7847 之间,平均值为0.4887。联合使用形态标记与分子标记计算遗传距离,将130份种质分成了5个近缘组,相邻组间产糖量、块根锤度、根腐病病情指数3项性状均有显著差异。结果表明被分析的甜菜种质遗传多样性比较丰富,遗传距离分析结果有生物学意义,可为种质创新工作提供参考。     

不同类型啤酒大麦品种遗传多样性及遗传差异的SSR分析

利用28对SSR引物对包括22份野生材料,8份耐盐碱材料,21份优质高产甘啤系列品种(系)材料和9份日本早熟材料在内的60份啤酒大麦品种资源的遗传多样性及其亲缘关系进行分析。结果表明,所用28对引物,有25对有多态性;聚类结果表明这些材料遗传相似系数分布在0.4792~0.9948之间。在遗传相似系数0.63的水平上,这些材料聚类为2大类,下分7个亚类。从聚类结果看出,不同类型材料基本各自聚为一类,表明不同类型品种(系)内遗传差异较小;不同类型品种(系)间遗传差异较大,杂交可能会产生较强的杂种优势和较高的产量潜力。     

澳洲坚果种质资源形态性状的遗传多样性分析

为了解引入澳洲坚果种质的遗传背景,以64份澳洲坚果种质为试材,采用41个形态性状对其进行了遗传多样性分析。41个形态性状的差异性和R型聚类分析结果表明：各性状间差异达到极显著水平;在欧氏距离（D）≈11.72处,41个性状聚为两组,组内各性状的欧氏距离较远,绝大多数性状间相对独立,对澳洲坚果种质的演化各具独立的意义,在澳洲坚果的分类中有较好的分辨能力。Q型聚类分析结果表明：64份种质的欧氏距离在3.15~12.39之间,具有较高的遗传多样性。在D≈12处可将64份种质划分为二个类群：第一类群仅包含T2 1份种质,为澳洲坚果栽培种的近缘种;第二类群包含剩下的63份种质,为澳洲坚果的栽培种。第二类群在D≈10处,可细分成3个亚类：第Ⅰ亚类包括7份种质（即695、Tet.-2、900、D4、HY、Tet.-1和广9）,属于粗壳种与光壳种的杂交种;第Ⅱ亚类包括A4和A16两个品种,属于粗壳种与光壳种的杂交种,但更偏重于光壳种;第Ⅲ亚类包括其他54份种质,都是光壳种的后代。获得的聚类结果与现有的分类体系一致;同时,获得了64份种质的形态性状聚类的亲缘关系图,其在生产种植中的品种搭配、育种中的杂交亲本选择和引种方面都具有指导意义。     

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。     

引入的美国小麦种质主要农艺性状的遗传多样性分析

旨在筛选适宜的小麦杂交亲本。以2015 年引入的51 份美国小麦种质为试验材料,研究了4 个质量性状的频率分布与遗传多样性,分析了9 个主要农艺性状间的相关性、遗传多样性,并以农艺性状为指标,对51 份小麦种质进行了聚类分析。参试小麦种质的株型以直立型为主,穗型以纺锤形为主,芒型以长芒为主,旗叶以下披型为主。产量与有效穗数(0.472**)极显著正相关,与千粒重(0.340*)显著正相关。9 个主要农艺性状间的差异性较大,各性状的变异系数除容重(1.71%)外,均超过了5%,以不孕小穗(55.21%)为最大,参试种质的遗传多样性丰富。Ward 法聚类将51 份种质分为了4 类,其中第1 类群10份种质的千粒重(40.31 g)、有效穗数（656.74 万/hm2）、产量(8718.63 kg/hm2)是4 个类群中最高,可作为重点亲本利用,其余种质可依据类群特征作为改良某一性状的中间材料利用。     

应用RAPD标记进行茶树优异种质遗传多态性、亲缘关系分析与分子鉴别

采用RAPD分子标记技术,对茶树优异种质资源的遗传多态性、亲缘关系和分子鉴别进行了研究。结果表明,20个引物在15份优异资源中得到1050个RAPD位点,平均52．5个位点／引物,70个位点／资源。在所获得的137条可重现谱带中,8条是单态的,129条是多态的,多态性程度达94．2％;引物的多态性相对频度为0．24～0．83,总平均为0．47;遗传距离在0．16～0．62之间,平均为0．37,这可能与我国是茶树的原产地和起源中心有密切关系。RAPD数据的类平均法聚类结果显示,15份资源可划分为3个类群,从相似性系数讨论了资源间的亲缘关系。应用12个引物产生的20个特异标记的存在和11个特异的缺失,可以鉴别所有15份优异茶树种质资源。RAPD可以作为茶树优异种质资源遗传多态性、系统演化和分子鉴别研究的有效手段之一。     

木薯种质资源遗传多态性SSR分子标记的研究

为了研究广西壮族自治区亚热带作物研究所从泰国、菲律宾、缅甸、印度尼西亚等国引进的25份木薯种质资源及海南省和广西壮族自治区亚热带作物研究所等选育的65份木薯品种(系)的遗传多样性,应用12对SSR引物对80个木薯种质进行PCR扩增,获得119个扩增带形,扩增产物的片段大小范围在100~300 bp之间,每对引物检测等位基因4~16个,平均为10个。根据品系间的遗传相似系数,利用UPGMA法进行聚类分析,以遗传相似系数0.46为阈值,将80个木薯品系分为两类。聚类分析结果表明,引进的国外资源和所选育的种质资源丰富了中国木薯种质库,拓宽了中国木薯遗传育种的物质基础,为进一步进行木薯新品种的选育和种质资源的收集及管理提供了遗传依据。     

茶树种质资源遗传多样性的RAPD分析

用随机扩增多态DNA（RAPD）标记对来自全国产茶省的31份种质资源、福建地区的10份种质资源以及湖南安化云台山种有性后代居群的30个单株的遗传多样性进行了检测。不同生态条件下的31份不同种质资源中,21个RAPD引物扩增出188条谱带,多态性比率为90.43%;福建10份种质资源,21个RAPD引物共扩增出154条谱带,多态性比率为81.81     

基于EST-SSR的西南茶区茶树资源遗传多样性和亲缘关系分析

利用本实验室cDNA文库测序所获得的茶树EST序列为主自行开发的24对和他人7对共31对EST-SSR引物,对60份西南茶区茶树资源进行了遗传多样性和亲缘关系分析.结果表明,西南茶区茶树资源的遗传多样性非常丰富.31对引物共检测到等位位点137个,每个引物为2～8个之间,平均4.42个.遗传多态性信息含量(PIC)在0.09～0.85之间,平均达0.63.观测杂合度(Ho)在0.07～0.94之间,平均值为0.53.UPGMA聚类表明,按相似系数为0.39可将参试的60份种质资源分为五大类.聚类结果在分子水平上显示了我国西南茶区种质资源间的亲缘关系,为以后种质资源保存和新品种选育提供一定的启示.     

Genetic diversity and population structure of ‘Khao Kai Noi’, a Lao rice (Oryza sativa L.) landrace,revealed by microsatellite DNA markers

Rice (Oryza sativa L.) is the main food for people in Laos, where it has been grown and eaten since prehistory. Diverse landraces are grown in Laos. ‘Khao Kai Noi’, a landrace favored for its eating quality, is held in the nationwide collection of traditional landraces in the Lao national genebank. Genetic diversity is crucial for sustainable use of genetic resources and conservation. To investigate the genetic diversity of ‘Khao Kai Noi’ for conservation, we genotyped 70 accessions by using 23 polymorphic simple sequence repeat markers. The markers generated 2 to 17 alleles (132 in total), with an average of 5.7 per locus. The total expected heterozygosity over all ‘Khao Kai Noi’ accessions was 0.271. Genetic variation was largest among accessions and smallest within accessions. Khao Kai Noi accessions were classified into three different genetic backgrounds, but there was unclear association between the three inferred population and name subgroups and geographical distribution. Most of the accessions were clustered with temperate japonica and showed genetic relatedness to rice from neighboring provinces of Vietnam, suggesting a Vietnamese origin. The results of this study will contribute to the conservation, core collection and future breeding of the Khao Kai Noi population.     

云南茶树种质资源的抗性鉴定和评价

为有效利用茶树种质资源,筛选适于高效抗性育种的茶树亲本材料。采用田间自然鉴定、低温处理试验等方法,对105份云南茶树种质资源进行了抗寒性和抗虫性鉴定,筛选出11份抗性表现较好的资源,其中抗寒性较强的资源有‘86-8-1’、‘86-9-12’、‘86-12-7’、‘86-6-9’、‘河头白尖毛茶’和‘弄岛黑茶’等6份,抗假小绿叶蝉虫性较强的资源有‘马鞍山大叶茶’、‘昌选2’和‘中叶2号’3份,抗咖啡小爪螨虫性较强的资源有‘基诺大叶茶’和‘丫口小茶’2份,抗根结线虫性较强的资源有‘84-1-1’和‘曼喷龙大叶茶’2份。这些抗性资源即可直接用于推广生产外,还可作为进一步单株选育和杂交育种的亲本或诱变育种的原始材料,为推动茶树新品种选育提供了良好的物质技术基础。     

Genetic diversity in apricot, Prunus armeniaca, aimed at improving resistance to plum pox virus

Plum Pox Virus, a non-persistent virus transmitted by aphids, causes serious damage to stone fruits. The apricot tree is very sensitive and in order to breed apricot cultivars resistant to Plum Pox Virus and establish breeding strategies, genetic diversity based on 10 enzymatic systems, six of which were polymorphic, has been studied. The plant material studied, 94 accessions, included the most important apricot cultivars grown in PPV-affected areas. Genetic diversity is high and showed important differences between the three geographical groups studied (North African, European and North American). The North American group was very diverse and allozymes can be used to identify three subgroups. Some North American PPV-resistant cultivars were very distant from the rest of the cultivars, mainly due to the presence of rare alleles found in an Asian apricot related species. These results support the hypothesis that Asian-related species might be the origin of PPV resistance within the North American cultivars. Three North American cultivars have been considered as putative donors of PPV resistance to the European cultivars because of their agronomic behaviour, chilling requirements and distance from European cultivars. However, to increase the genetic variability of the European group and thereby to favour recombination, the study of Asian apricot resources is also recommended.     

Allozyme diversity of Russian wildrye accessions

Analysis of genetic diversity among plant accessions plays an important role in developing strategies for plant breeding and the conservation of genetic resources. Therefore, we sought to estimate the extent of genetic diversity present among and within 29 Russian wildrye accessions, which were collected from widespread geographic sites. We assessed the genetic diversity of eight enzymes found in 29 Russian wildrye accessions using vertical polyacrylamide gel electrophoresis. The genetic diversity of each accession was estimated from standard genetic parameters that included (1) the number of polymorphic loci; (2) the average number of alleles per locus; (3) the observed and expected heterozygosity. The eight enzymes were encoded by 13 putative loci and 46 alleles. Allozyme analyses revealed a large number of polymorphic loci among the 29 accessions and some of the accessions carry rare alleles and trace their origin to sites in Xinjiang, China, where Russian wildrye is indigenous. The accessions with rare alleles require additional evaluation to determine whether they possess unique phenotypic traits which would be useful in applied plant breeding.     

黄瓜种质资源形态学标记和SRAP标记的遗传多样性分析

旨在探索黄瓜种质资源的遗传多样性,为今后黄瓜选育优良品种提供可靠依据。以48份黄瓜种质资源为材料,用DPS软件对各品种的13个表型性状进行聚类分析,同时利用SRAP分子标记对其进行遗传多样性研究。结果表明:根据果实性状等形态学标记聚类分析得出,在阈值75.0处,可以将48份黄瓜种质资源分成5大类群。利用UPGMA法对SRAP分子标记结果聚类分析发现,黄瓜种质间的遗传相似系数在0.52~0.93之间,在遗传相似系数为0.64处,可以将其分成5大类群,形态学标记和SRAP分子标记的聚类结果存在较大差异。由此可见,SRAP分子标记较形态学标记能更好地分析品种间亲缘关系的远近,对黄瓜遗传多样性研究更具指导意义。