农户保存与种质库保存的同近名地方稻品种的遗传多样性研究

通过对湖南农户自留种原地保存(简称农户保存)与异地低温保存在湖南种质库(简称种质库保存)的92份同近名水稻材料(7组,同近名材料6组)间的表现型及基因型进行分析,鉴定同近名品种间遗传距离,为之后有效保存、针对性供种、高效利用提供理论依据。结果表明,供试同近名材料间,及农户保存与种质库保存的同近名材料间在表现型性状上都有极显著差异。通过SSR标记基因型比较农户保存与种质库保存湖南同近名材料,发现除E组外,其他组都是农户保存的等位基因变异数小于种质库保存的等位基因变异数,说明农户保存的材料在年复一年的种植、收种过程中经历了自然选择和人工选择留种,进行了加代纯化。除C、E组外,在同近名组内SSR标记遗传相似系数显示,农户保存的材料间种质库保存的材料间农户保存材料与种质库保存材料,表明农户自留种保存的同近名水稻资源值得收集评价。     

晒黄烟种质资源遗传多样性分析与评价

为加强晒黄烟资源的收集保存与利用,本研究对来源于国家烟草中期库的6份晒黄烟和新收集的26份晒黄烟进行了SSR分子标记研究,根据来源不同将32份种质分成Z(资源库)、G(广西贺州)以及M(广西百色)3个群体。结果表明,(1)106对SSR引物共检测到110个位点,其中85个为多态性位点,多态性比率为77.27%,种质间的遗传相似系数变异范围为0.49~0.95,表明种质间遗传基础比较狭窄。(2)3个群体内遗传差异由大到小分别为:ZMG。Z与M的遗传相似系数为0.7762,遗传距离相对较远,G与M遗传相似系数为0.8963,遗传距离较近。(3)在相似系数0.49处可将32份种质分成2类,第1类包括寸三皮和大宁旱烟籽,第2类包括3个亚类,其中来源于Z群体的公会晒烟与新收集晒黄烟品种(系)归为一类,Z群体的其他种质与新收集种质遗传距离较远。(4)来自不同地点的同名种质大宁烟遗传距离相对较远,相似系数为0.788。不同名称的公会包盖烟和凤凰黄烟遗传相似性最高,相似系数为0.939。     

太湖粳稻同名地方品种的遗传差异

选用45个SSR标记分析太湖流域荔枝红、老来青、太湖青和老虎稻共4组粳稻同名地方品种的遗传差异。结果表明:同名地方品种平均Nei遗传距离为0.120~0.171,遗传同一性程度较高,其中有8对同名品种难以区别,但多数品种仍然存在一定的遗传变异,且个别品种差异较大;同名品种遗传差异与种质来源、品种名称的近似程度没有关系。     

宁夏杂草稻的遗传多样性及其亲缘关系分析

以宁夏杂草稻、选育品种、地方品种共143份水稻种质为试验材料,进行主要农艺性状的的表型鉴定评价,并利用24对SSR引物进行不同类型水稻种质的遗传多样性比较、遗传相似性和聚类分析。表型评价表明,宁夏杂草稻表现为矮秆和早熟,表型变异范围较大;多数杂草稻种皮呈红色,颖壳呈秆黄色,均落粒。SSR标记分析结果,共检测到141个等位基因,每个位点等位基因数目变异在3~11个,平均为5.8333个;Nei's基因多样性指数变幅为0.2241~0.8065,平均为0.5219。杂草稻种质的等位基因数、有效等位基因数、Shannon指数均高于选育品种和地方品种。在不同来源杂草稻群体中,来自吴忠和永宁东河的杂草稻Nei's基因多样性指数最高,分别为0.4912和0.4814,而来自青铜峡的杂草稻Nei's基因多样性指数最低,为0.2802。相似性分析表明,杂草稻与地方品种高度相似,相似系数高达0.9585,而杂草稻与选育品种的相似性较低,其相似系数为0.4584;选育品种与地方品种的相似系数只有0.3560。聚类分析表明,参试材料分为3个类群,其中选育品种单独聚类于第Ⅰ类群,其遗传背景明显区别于杂草稻和地方品种;第Ⅱ类包括大部分杂草稻和地方品种,不同来源杂草稻及地方品种间分布比较均匀;第Ⅲ类是由小部分杂草稻和地方品种组成。宁夏杂草稻的分布没有明显的区域性,宁夏杂草稻与地方品种高度融合且遗传相似性很高。     

陕棉抗病种质及其衍生品种的遗传多样性与群体结构研究

通过72个分布于棉花全基因组的SSR标记,对54份陕棉抗病种质及其衍生品种的遗传多样性与群体结构进行了分析。结果表明:(1)54份陕棉种质间的遗传相似系数在0.733 3~0.987 2之间,其中材料间相似系数≤0.90的占11.1%,相似系数≥0.95的占55.6%,相似系数在0.90~0.95的占33.3%。(2)72个SSR标记等位基因变异的多态性信息含量(PIC值)在0.04~0.68,平均为0.33。(3)基于遗传距离的UPGMA聚类分析显示,在遗传相似系数为0.877时将54个品种分为5类,第Ⅰ类44个品种,第Ⅲ类7个品种,第Ⅱ、Ⅳ、Ⅴ类各1个品种。(4)基于数学模型的聚类和群体结构分析显示,54份种质归属于4个组群。研究认为,54份材料间遗传相似系数较大,遗传基础比较狭窄,多样性很低。     

黑龙江省近年审定水稻品种基于SSR标记的遗传多样性分析

为评估黑龙江省水稻品种的遗传基础,利用24个用于水稻DNA指纹图谱构建的SSR标记以及其他均匀分布于水稻12条染色体的38个SSR标记,对黑龙江省近年审定的73个水稻常规稻品种进行遗传多样性分析。结果表明,在62个SSR标记位点中,共检测到142个等位基因,平均每个标记2.3个,多态性比率平均为71.0%,多态性频率变幅为0~0.775,平均值为0.246。供试品种间两两遗传相似系数的平均值为0.759,变幅为0.622~0.966,且96.4%的品种间遗传相似系数在0.66~0.86之间,表明供试的73个品种亲缘关系较近。通过SSR标记基因型聚类分析将这些品种划分为6个类群,与系谱分析趋势一致,类群间的差异主要表现在生育期和米质方面。综上所述,黑龙江省近年审定的水稻品种遗传基础狭窄,在育种中需要导入新的种质资源,加强种质资源创新,以期丰富水稻品种的遗传多样性,进一步提高水稻产量和抗性。     

国内外甜高粱种质遗传多样性的SSR分析

用24对扩增带型稳定的SSR引物,研究了206份国内外甜高粱种质资源的遗传变异,共检测出220个等位基因,每对引物检测出2～19个等位基因。引物位点的多态信息含量指数(PIC)变幅在0.50～0.87。利用220个多态性标记计算206份甜高粱品种之间的遗传相似系数(GS),范围在0.32～0.96之间。利用SSR标记遗传相似系数矩阵,按UPGMA方法对206份甜高粱品种进行聚类分析,将其分为A、B两大组,B组只包含3个品种,与其他品种遗传关系较远,A组进一步被分成15个类群,农艺性状近似的聚在同一类群。     

基于遗传和表型特征的海岛棉遗传多样性分析

依据海岛棉种质资源的遗传及表型特征对其遗传多样性进行研究非常重要,可为海岛棉杂交育种选配亲本、引进新的种质资源拓宽优异基因范围以及培育海岛棉新品种提供理论根据。本研究通过利用125对SSR分子标记鉴定结果和13个农艺性状2年田间表型调查结果,对94份海岛棉种质资源进行遗传多样性分析,将这些材料按照遗传和表型特征进行类群的划分和比较,结果表明:(1)通过标记分析共检测到420个位点,其中249个为多态性位点,并应用Nei-Li相似系数法对94份材料间的遗传相似系数进行评估,发现94份海岛棉资源材料的遗传相似系数在0.46~0.95之间浮动,同时利用SSR分子标记将94份海岛棉资源材料划分为4大类群,分类结果与系谱分析基本吻合。(2)对94份海岛棉资源材料进行13个农艺性状及品质性状2年调查分析,发现供试材料品质性状的变异范围较广,而产量性状的变异范围相对较小。其中,各品种中马克隆值的多样性指数最高,最小的是单铃重。聚类分析发现,第Ⅰ类群产量性状的平均值较高;第Ⅱ类群虽在产量性状上不占优势,但其品质性状的表现较其他组别优异;第Ⅲ类群多为低产低质品种;第Ⅳ类群品种品质较优,产量变化范围较大。(3)利用SSR标记和农艺性状分析2种方法对94份海岛棉资源材料进行分析,结果均显示出较丰富的遗传多样性;2种方法的聚类结果基本一致,聚类结果与地理分布有明显的联系。     

宁夏60份粳稻种质资源遗传多样性分析

试验用SSR分子标记对60份宁夏粳稻种质资源进行遗传多样性分析。103对SSR引物表现多态性的有58对,共扩增出212条多态性条带,等位变异范围为2～9,平均每对引物3.7个;多态性信息含量(PIC)变幅为0.032～0.788,平均为0.403;高多态性位点主要发生在3号、6号和11号染色体上,而无多态性或低多态性位点主要发生在1号和10号染色体上;成对供试材料的遗传相似系数GS值变幅为0.642～0.958,平均为0.790,单个供试材料的平均GS值变幅为0.710～0.816,平均为0.781,亲缘关系较近;UPGMA聚类表明,在遗传相似系数约0.785处,供试材料可被分为11类,大部分材料被聚在一类中。     

三年桐EST-SSR标记的开发与种质遗传多样性分析

以三年桐品种对年桐发育中的种子为材料,构建c DNA文库,获得3202个原始EST序列,经过去除冗余和低质量序列后,获得1047条非冗余单一序列,利用MISA软件从其中的173个非冗余EST序列中搜索得到212个SSR位点。其中,二核苷酸重复类型为主导(68.39%),其次是三核苷酸重复类型(25.94%),其优势基元为AG/CT(43.87%)、AT/AT(19.34%)和AGC/GCT(5.66%)。针对可设计引物的68个序列进行EST-SSR引物设计,结合PCR扩增和数据分析,鉴定出14对多态性标记,用该14对引物对169份三年桐种质资源进行遗传多样性检测,共得到41个等位基因(Na),平均每对引物扩增出2.93个等位基因,期望杂合度(He)变幅为0.08~0.63,平均值为0.33,多态性信息含量(PIC)变幅为0.08~0.56,平均值为0.3,表明14对EST-SSR标记多态性较高,能较好地反映三年桐种质的遗传多样性。三年桐种质资源按群体进行非加权配对算术平均法(UPGMA)聚类分析,群体间的相似度变幅为0.9604~0.9986,遗传距离变幅为0.0022~0.0404,表明三年桐群体间的遗传多样性相对较低,亲缘关系较近。对169份三年桐种质资源个体进行聚类分析,结果显示不同地理种源的遗传关系缺乏明显的地理结构。     

SSR标记揭示的云南地方稻品种遗传多样性及其保育意义

为了探索水稻(Oryza sativa L.)地方品种的遗传多样性及其有效保育方法,对采自云南省17个村寨的82个水稻地方品种和3个国际常用的典型籼稻和粳稻品种进行了微卫星(SSR)分子标记的分析.利用19对SSR引物在85个水稻品种中共扩增出了83个基因型,其分子量变异在100～500 bp之间.基于各品种SSR基因型遗传相似系数聚类分析而获得的UPGMA树状图表明各水稻品种之间存在较大的遗传多样性,其相似系数变异在0.15～0.90之间.但这些地方品种的遗传多样性并非呈均等的地理分布.这85个水稻品种在相似系数为0.52之处分为二组,其中一组包括几乎所有的籼稻品种,而另一组包括全部的粳稻品种,表明SSR标记能很好揭示水稻籼-粳分化.同时,有些来自不同采集地的同名品种表现出一定的遗传差异,说明同名异物的现象存在.云南水稻地方品种具有丰富的遗传多样性,对其有效保育十分重要和迫切,但只有根据遗传多样性的水平和分布特点,采用正确的保育对策和取样方法才能确保对云南水稻地方品种的有效保育.结果进一步表明,选用适当的微卫星引物,可以为准确鉴定籼稻和粳稻品种及研究其进化规律提供有效的分子标记方法,并有利于有目标的水稻遗传资源保育和育种创新.     

SSR标记揭示的云南地方稻品种遗传多样性及其保育意义

为了探索水稻(Oryza　sativa　L.)地方品种的遗传多样性及其有效保育方法,对采自云南省17个村寨的82个水稻地方品种和3个国际常用的典型籼稻和粳稻品种进行了微卫星(SSR)分子标记的分析。利用19对SSR引物在85个水稻品种中共扩增出了83个基因型,其分子量变异在100～500　bp之间。基于各品种SSR基因型遗传相似系数聚类分析而获得的UPGMA树状图表明各水稻品种之间存在较大的遗传多样性,其相似系数变异在0.15～0.90之间。但这些地方品种的遗传多样性并非呈均等的地理分布。这85个水稻品种在相似系数为0.52之处分为二组,其中一组包括几乎所有的籼稻品种,而另一组包括全部的粳稻品种,表明SSR标记能很好揭示水稻籼-粳分化。同时,有些来自不同采集地的同名品种表现出一定的遗传差异,说明同名异物的现象存在。云南水稻地方品种具有丰富的遗传多样性,对其有效保育十分重要和迫切,　但只有根据遗传多样性的水平和分布特点,采用正确的保育对策和取样方法才能确保对云南水稻地方品种的有效保育。结果进一步表明,选用适当的微卫星引物,可以为准确鉴定籼稻和粳稻品种及研究其进化规律提供有效的分子标记方法,并有利于有目标的水稻遗传资源保育和育种创新。     

Assessment of genetic diversity in Indian rice germplasm (Oryza sativa L.): use of random versus trait-linked microsatellite markers

Assessment of genetic diversity in a crop germplasm is a vital part of plant breeding. DNA markers such as microsatellite or simple sequence repeat markers have been widely used to estimate the genetic diversity in rice. The present study was carried out to decipher the pattern of genetic diversity in terms of both phenotypic and genotypic variability, and to assess the efficiency of random vis-à-vis QTL linked/gene based simple sequence repeat markers in diversity estimation. A set of 88 rice accessions that included landraces, farmer’s varieties and popular Basmati lines were evaluated for agronomic traits and molecular diversity. The random set of SSR markers included 50 diversity panel markers developed under IRRI’s Generation Challenge Programme (GCP) and the trait-linked/gene based markers comprised of 50 SSR markers reportedly linked to yield and related components. For agronomic traits, significant variability was observed, ranging between the maximum for grains/panicle and the minimum for panicle length. The molecular diversity based grouping indicated that varieties from a common centre were genetically similar, with few exceptions. The trait-linked markers gave an average genetic dissimilarity of 0.45 as against that of 0.37 by random markers, along with an average polymorphic information constant value of 0.48 and 0.41 respectively. The correlation between the kinship matrix generated by trait-linked markers and the phenotype based distance matrix (0.29) was higher than that of random markers (0.19). This establishes the robustness of trait-linked markers over random markers in estimating genetic diversity of rice germplasm.     

Analysis of genetic diversity among indigenous landraces from sesame (Sesamum indicum L.) core collection in China as revealed by SRAP and SSR markers

The molecular genetic diversity of 404 indigenous landraces from sesame core collection in China were evaluated by 11 SRAP and 3 SSR markers, 175 fragments were generated, of which 126 were polymorphic with an average polymorphism rate of 72%. Jaccard’s genetic similarity coefficients (GS=0.7130), Nei’s gene diversity (h=0.2418) and Shannon’s Information index (I=0.3847) were calculated, a dendrogram of the 404 landraces was made, landraces from various zones were distributed throughout the dendrogram, accessions from different agro-ecological zones were indistinguishable by cluster analysis, geographical separation did not generally result in greater genetic distance, a similar pattern was obtained using principal coordinates (PCO) analysis. As to seven agro-ecological zones, the maximum Nei’s gene diversity (h = 0.2613) and Shannon index (I = 0.3980) values in zone VII indicated that they were genetically more diverse than those in other zones, while the least genetically diverse region was zone III (h = 0.1772, I = 0.2858). Nei’s genetic identity and genetic distance among landraces from seven agro-ecological zones were also analyzed, the genetic relationship of seven zones was inferred using the UPGMA method. This study demonstrated that SRAP and SSR markers were appropriate for evaluation of sesame genetic diversities. There existed extensive genetic diverse among indigenous landraces and the abundance of genetic diversity of landraces in different agro-ecological zones was various. Understanding of these characteristics of indigenous landraces in China can provide theoretical foundation for further collection, effective protection and reasonable utilization of these sesame landraces in breeding.     

中俄茄子种质资源遗传多样性研究

利用25对SSR分子标记和24个表型性状对105份中俄茄子材料进行遗传多样性分析。表型变异分析结果表明:24个表型性状在中俄材料间均表现出了不同程度的多样性,但是同一性状在中俄材料中多样性不同;主成分分析可将24个表型性状概括为果形因子、颜色因子、果实外观因子、叶片形态因子、果萼刺和花药条纹6个指标,其中果实特征占主要成分;利用UPGMA法进行聚类,遗传相似系数在0.4~0.8之间,平均值0.6。25对多态性SSR标记,扩增出122个条带,含有等位基因82个,其中有效等位数24.8个,PIC值为0.3~0.7。分子聚类的遗传相似系数在0.5~1之间,平均值是0.7。表型聚类和分子标记聚类的结果相似,105份茄子种质资源间的类群划分与地理来源之间没有直接关系,但与茄子的果实性状有一定的相关性。     

云南栽培稻种SSR遗传多样性比较

采用64个SSR标记对96份云南水稻（Oryza sativa）地方品种和选育品种的遗传多样性进行比较分析。结果发现64个标记都具有多态性,共检测到741个等位基因,每个多态性位点检测到的等位基因数为2—29个,平均11．57个：Nei基因多样性指数（He）范围在0．345（RM321）-0．932（RM1）之间,平均为0．56。水稻品种的遗传多样性并非按地理位置均匀分布,而是在相似系数为0．17的水平上明显分为2个不同类群,即籼稻类群和粳稻类群,且籼粳亚种间的SSR多样性差异不明显,籼稻平均等位基因数（Ap）和Nei基因多样性指数（Ap=10．6,He=0．46）与粳稻品种（Ap=10．7,He=0．48）十分接近,可能与这些品种间存在一定频率的基因交流有关。糯稻和非糯稻在籼稻群和粳稻群中都有表现,没有特别的分布规律。云南栽培稻选育品种与地方稻亲缘关系较近,其遗传基础可能来源于云南水稻地方品种。本研究结果表明,SSR标记能较好地区分云南栽培稻品种,且云南水稻地方品种遗传多样性丰富,存在大量的优质性状可供育种实践选择。     

云南栽培稻种SSR 遗传多样性比较

采用64个SSR标记对96份云南水稻(Oryz a sativa)地方品种和选育品种的遗传多样性进行比较分析。结果发现64个标记都具有多态性, 共检测到741个等位基因, 每个多态性位点检测到的等位基因数为2-29个, 平均11.57个; Nei基因多样性指数(He)范围在0.345(RM321)-0.932(RM1)之间, 平均为0.56。水稻品种的遗传多样性并非按地理位置均匀分布, 而是在相 似系数为0.17的水平上明显分为2个不同类群, 即籼稻类群和粳稻类群, 且籼粳亚种间的SSR多样性差异不明显, 籼稻平均等位基因数(Ap)和Nei基因多样性指数(Ap=10.6, He=0.46)与粳稻品种(Ap=10.7, He=0.48)十分接近, 可能与这些品种间存在一定频率的基因交流有关。糯稻和非糯稻在籼稻群和粳稻群中都有表现, 没有特别的分布规律。云南栽培稻选育品种与地方稻亲缘关系较近, 其遗传基础可能来源于云南水稻地方品种。本研究结果表明, SSR标记能较好地区分云南栽培稻品种, 且云南水稻地方品种遗传多样性丰富, 存在大量的优质性状可供育种实践选择。     

Genetic diversity in basmati rice (Oryza sativa L.) germplasm as revealed by microsatellite (SSR) markers

Genetic diversity among rice genotypes, including 15 indica basmati advance lines and 5 basmati improved varieties were investigated by 28 SSR markets including one indel marker. The SSRs covered all the 12 chromosomes that distributed across the rice genomes. The mean number of alleles per locus was 3.60, showing average number of polymorphism information content was 0.48. A total of 101 alleles were also identified from the microsatellite marker loci. A number of SSR markers were also identified that could be utilized to differentiate between rice genotypes. Pair wise Nei,s genetic distance between rice genotypes ranged from 0.07 to 0.95. The dendrogram based on cluster analysis by using SSR polymorphism that grouped the 20 genotypes of rice in to five clusters based on their genetic similarity. The result could be useful for the identification and selection of the diverse genotypes for the future cross breeding program and development of new rice varieties.     

Morphological and molecular diversity reveal wide variability among sorghum Maldandi landraces from India

Maldandi is a popular sorghum variety for post-rainy or rabi cultivation in southern and central states of India, which is predominantly used for food purpose. Over time many landraces have been collected from these states which have vernacular connection with Maldandi. Genetic diversity among 82 Maldandi landraces, collected from such geographical regions was evaluated using both morphological (quantitative and qualitative) and SSR markers. In general, both morphological and SSR diversity revealed wide variability among the accessions studied. Euclidean distances based on 17 quantitative traits classified the accessions into two major clusters with two out groups, while the 19 qualitative traits clustered the accessions in one major cluster with six out groups. Sixteen out of 20 (80%) SSR markers detected polymorphism among the accessions with average PIC value of 0.36. Un-weighted neighbor joining clustering grouped the accessions into three clusters with 46, 16 and 17 accessions, respectively throwing three outliers. Average similarity coefficients of 0.62 and 0.34 based on morphological (qualitative) and SSR data indicated presence of wide variability among the Maldandi landraces. The standard check, M 35?C1 (a selection from the original Maldandi) could not be differentiated from EP 98, LG 2, LG 10, IS 4509 and IS 40791 based on qualitative data alone, while EP 54 and IS 33839 were indistinguishable from M 35?C1 solely using SSR markers. Either of the dendrogram threw unique grouping patterns with some identity. Thirteen promising Maldandi accessions selected based on field performance as well as morphological and molecular diversity could be used in the rabi improvement programme. SSR markers combined with morphological traits may effectively be used for designing breeding strategy and management of biodiversity and conservation of Maldandi genetic resources.