SSR标记遗传距离与结球甘蓝杂种优势的关系分析

利用SSR标记对23份春甘蓝自交系和29份秋甘蓝自交系进行遗传多样性分析,结果表明:春甘蓝自交系在遗传相似系数0.61处可以划分为极早熟和早熟2个类群。秋甘蓝自交系在遗传相似系数0.58处可以分为中晚熟群、中早熟群和中熟群3个类群。从上述材料中挑选15份代表性材料作为亲本,采用完全双列杂交法组配105个杂交组合,对其进行杂种优势分析,同时探究SSR分子标记遗传距离与杂种优势之间的关系。结果发现,不同类群间杂交或同一类群不同亚群间杂交产生的后代杂种优势较强,遗传距离与全株质量中亲优势的相关性达显著正相关,表明基于SSR分子标记划分的类群对于杂种优势的预测具有一定的价值。此外还发现,在105个杂交组合中,全株质量中亲优势最强的10个组合的组配方式均为春甘蓝×秋甘蓝,表明春甘蓝×秋甘蓝可能是一种潜在的杂种优势利用模式。     

部分香蕉品种SSR指纹图谱的构建

采用SSR标记技术构建香蕉品种的分子指纹图谱,为香蕉品种鉴定提供依据。以56份香蕉种质为材料,从199对引物中筛选出5对多态性及稳定性较高的SSR引物进行PCR扩增。5对引物在56个品种中扩增出的多态性带数在11～16个,平均为13.8条;引物的多态信息含量(PIC)在0.8490～0.9022,平均0.8727。依据香蕉SSR带型特征,对每个引物生成的不同带型直接编号,简化香蕉SSR带型记录方法,并利用每个品种的带型编号,建立其DNA分子指纹图谱,5对引物可将56份供试香蕉材料完全区分开。表明SSR标记技术可用以鉴定香蕉种质。     

厚皮甜瓜遗传多样性的SSR分析

采用61对SSR特异引物对46份厚皮甜瓜材料进行分析,其中52对扩增出条带,47对引物具有多样性,扩增带分子量在150～1500bp,187条谱带中154条谱带具有多态性,多态率占82.35%,平均每个引物可扩增出3.60条带。同时,对材料网纹、果形、单果质量、有无条带、果皮颜色、果肉颜色、肉质、种子、有无麝香味、裂叶、是否自落和花性型等12个性状进行了田间调查,经过phylip软件和NTSYS软件分析后,计算出材料间遗传距离,并做出SSR分子标记和性状2个聚类图。结果显示,46份材料的遗传距离在0.0188～1.2119,而单一性状气味、果皮颜色、果肉颜色和表面网纹的遗传距离都小于0.1,十分接近;2种聚类分析结果存在较大差异,这与供试材料的亲缘关系十分复杂,大部分材料来源相近,具有相同的亲本,和回交亲本存在一定关系。     

普通杏品种SSR遗传多样性分析

利用来自杏、桃和扁桃的25对SSR多态性引物对66个普通杏品种进行了PCR扩增及变性聚丙烯酰胺凝胶电泳,共检测出284个等位位点,每对引物的等位位点数在3～17之间,平均为11.36。通过NTSYS软件计算得到的Dice相似性系数为0.083～0.987,平均值为0.370,表明中国普通杏种质资源的遗传多样性丰富。UPGMA法聚类将66份材料分为5个组。SSR标记反映出的品种间亲缘关系与根据地理生态类型对杏种质的分类结果基本一致。来自四川和贵州的多数品种独立聚成一组,表现出与其它品种较远的亲缘关系,该地区可能存在特异性较高的种质资源。证实了扁桃基因组SSR引物可用在杏SSR标记的研究中。     

甘肃省梨地方品种资源遗传多样性及亲缘关系SSR分析

为了解甘肃省不同生态区地方梨(Pyrus L.)品种资源的遗传多样性及亲缘关系,采用28对SSR引物对119份甘肃省梨地方品种或类型进行鉴定分析。供试28对SSR引物中有7对引物具有较好的多态性,7对引物共扩增出49条带,其中多态性条带28条,平均多态性位点百分率为63.27%;观察杂合度(H0)介于0.068~0.809,平均为0.591;平均多态性信息含量(PIC)(变异范围)介于0.365~0.680,平均为0.545;香农指数(I)介于0.713~1.482,平均为1.094;引物NH005b、NH007b及NH008b多态性较好,品种鉴定效率较高。所有材料遗传相似系数分布在0.074~1.000,平均为0.597;聚类分析显示,7对SSR引物可将119份供试梨品种资源在遗传相似性系数1.076处分为7组,主成分分析和UPGMA结果基本一致;群组内各品种资源由于其遗传相似性,更多地被聚在一起,但主成分分析并没有很明显地被分为多个类群或者分成几个主成分。研究结果揭示了甘肃省梨地方种质资源具有丰富的遗传多样性和广泛的遗传变异,还对根据形态特征无法确定归属的梨品种据其相互间的亲缘关系进行了适当归类,为进一步分类和利用甘肃省梨地方资源提供了理论依据。     

SSR标记在南瓜亲缘关系分析中的应用

以20份分属10个品种群的中国南瓜、印度南瓜和美洲南瓜材料及1份印度南瓜和中国南瓜的种间杂交种为试材,采用390对SSR引物对21份材料进行了多态性及亲缘关系分析.结果表明:供试材料之间具有丰富的遗传多样性,美洲南瓜与中国南瓜亲缘关系较近,二者与印度南瓜的亲缘关系较远;同一亚种内及同一品种群内材料之间具有更近的亲缘关系;利用SSR分子标记做出的聚类结果基本可以将供试材料按照不同品种群分开.     

山葡萄种内遗传多样性的SSR分析

利用26对SSR引物对124份山葡萄种质资源的遗传多样性初步分析,等位基因(Na)数平均为3.6923,有效等位基因(Ne)数平均为2.5779,Shannon多样性指数(I)平均为1.0195,基因多样度(Nei)平均为0.5762。野生种质资源的遗传多样性高于选育品种;而野生种质资源中黑龙江省的遗传多样性高,其次是吉林省野生资源,辽宁省野生资源最低。山葡萄种质的遗传相似性系数J为0.224～0.972,平均遗传相似系数为0.588。根据遗传相似性系数进行UPGMA聚类,建立树状聚类图。利用26对SSR标记能将供试的124份山葡萄种质相互区分,在遗传相似性系数0.39处将供试山葡萄种质资源分为6大类群,多数种质的聚类和山葡萄长期生长发育的地理分析研究结果一致。     

寒地李和杏遗传多样性SSR分析

以27份适宜北方生长的李、杏品种为试材,采用SSR分子标记技术对其进行遗传多样性分析,并运用UPGMA聚类分析法,分析了27份试材的亲缘关系,为寒地李、杏种质资源保存和品种选育提供分子生物学依据。结果表明:筛选的25对SSR多态性引物共扩增等位位点245个,其中多态性位点240个,多态性比率为97.96%。每对引物的等位基因数量为4~13,平均值为9.8。有效等位基因数平均值为2.740 5,Shannon′s信息指数平均值为1.052 0,多态性信息含量平均值为0.595 5,表明试材具有较高的遗传多样性。聚类分析结果表明,在遗传相似系数0.612处,27份试材可以分为李和杏两大类群。     

黑龙江省黑木耳主栽品种SSR遗传多样性初探

从30对SSR引物中筛选出多态性较好的引物对黑龙江省黑木耳主栽品种进行SSR遗传多样性分析和主坐标分析,结果筛选出8对扩增多态性较好的引物,UPGMA法进行聚类分析,可将其分为三类,目前主栽黑木耳品种聚为一类,以前主栽黑木耳品种聚为一类,分离野生黑木耳聚为一类。供试黑木耳菌株遗传相似系数在0.60~0.97,表明遗传多样性较高,主坐标分析也可将其分为三类,这与UPGMA聚类结果一致。     

基于SSR分子标记的葡萄品种遗传多样性分析

以15份葡萄品种为试材,采用SSR分子标记技术,研究了15份葡萄品种资源的遗传多样性。结果表明:从245对引物中筛选出49对清晰、稳定性好的多态性引物。49对引物在15份材料中共扩增出235条带,均为多态性条带,多态性百分率为100%。每对引物扩增的等位位点数为2~9个,相似性系数分析结果表明,供试的15份葡萄材料的遗传相似系数为0.660~0.860,其平均遗传相似系数为0.760。聚类分析表明,在遗传相似系数0.672处,15份葡萄材料可分为三大类群。第一大类包括2份欧美杂种(V.vinifera L.×V.labrusca L.)和1份美洲种(V.labrusca L.)品种;第二大类为8份欧亚种(V.vinifera L.)葡萄品种;第三大类包括2份山欧杂种(V.amurensis Rupr.×V.viniferaL.)和2份山葡萄(V.amurensis Rupr.)品种。可见,欧亚种和美洲种葡萄亲缘关系相对较近,而山葡萄与二者亲缘关系相对较远。这些引物中,VMCNG4B9、VMC3G9能将15个葡萄品种区分开,为今后开展葡萄品种指纹图谱构建奠定基础。     

利用SSR研究不同国家桃育成品种的遗传多样性

利用34对SSR分子标记对来自不同国家的56份桃育成品种进行遗传多样性分析。筛选的13对SSR引物共检测出226个等位基因,其中多态性等位基因为222个。桃群体的平均Nei’s基因多样度为0.224,Shannon遗传多样性表型指数为0.367,说明桃总群体遗传变异较低;基因分化系数为0.081,与AMOVA分析结果8.13%相近,说明2者遗传变异以群体内遗传变异为主;基因流值为5.657,则说明不同国家间桃育成品种交流比较频繁。根据Nei’s基因多样度和Shannon遗传多样性表型指数2指标所得,欧美品种群遗传变异最高,其次为中国,最后为日本。UP-GMA聚类分析结果表明,品种间的遗传距离与系谱关系基本吻合。     

20份葡萄种质亲缘关系的SSR分析

利用SSR标记对20份葡萄材料进行了基因组多态性分析,从245对引物中筛选出19对用于葡萄的SSR扩增。共扩增出144条带,均为多态性条带,多态性百分率为100%。根据SSR扩增结果,利用NTSYSpc2.10e软件进行Jaccard相似性系数分析,20份葡萄材料的遗传相似系数为0.630～0.900,平均遗传相似系数...     

Genetic diversity in Apium graveolens and related species revealed by SRAP and SSR markers

Genetic diversity is essential to crop improvement. However, lack of molecular markers prevents the understanding of genetic diversity in celery and related species. In this study, SRAP and SSR markers was firstly used to evaluate genetic variation in 68 accessions of Apium graveolens and related species. A total of 888 bands were generated by 40 primer combinations of SRAP and 32 bands were produced by eight SSR markers. Of the 920 bands, 95.1% were polymorphic between A. graveolens and related species, and 49.2% were polymorphic within A. graveolens. Cluster and structure analysis could distinguish local celery, celery, and related species. These results suggested that both SRAP and SSR technologies can be efficiently used to characterize genetic variation and analyze genetic relationship in celery and related species.     

板栗野生居群遗传多样性研究

使用从板栗中提取的10个微卫星引物对4个中国栗野生居群的69个个体进行扩增,共检测到84个等位基因,每个位点的等位基因数为4～13,每位点的平均等位基因数目为8.4个,平均有效等位基因数(Ne)为4.998,平均期望杂合度(He)为0.777,平均PIC值为0.739,Nei’s多样性指数(h)为0.771,以陕西汉中居群具有最高的遗传多样性。遗传分化系数Gst仅为0.141。UPGMA树状聚类图表明4个野生群体被分为两部分,其中云南、四川、安徽3个居群距离相近位于同一组,此结果与PCA分析结果一致,2种方法均显示居群间的遗传关系与实际地理分布不完全相关。     

杨桃遗传多样性的形态特征与RAPD标记的相关性分析

【目的】为指导杨桃种质资源的引进以及良种选育提供科学依据,【方法】采用形态标记数量聚类分析和RAPD分子标记相结合,对广东地区10份杨桃品种资源进行遗传多样性分析,并将形态学聚类和RAPD分子标记聚类结果加以对比。【结果】在所观察的12个形态性状中,变异系数为14.08%~49.71%,平均变异系数为25.38%。从100条RAPD随机引物中筛选出10个引物,共扩增出58条带,其中53条为多态性带,多态率达93.02%。聚类分析结果表明,形态标记和RAPD标记都可依果实风味将供试材料分组,即甜味和酸味。2种标记方法的相关系数为r0.01=0.685 3,达到显著水平。【结论】杨桃具有丰富的遗传多样性,2种方法聚类结果相似,且相关性高,具有较高的可靠性。     

Analysis of genetic diversity among some Persian walnut genotypes (Juglans regia L.) using morphological traits and SSRs markers

There is a high diversity among cultivated walnut trees in Iran due to its long time of seed propagation and vast area of cultivation. In this study some morphological characters as well as Simple Sequence Repeat (SSRs) markers were used to analyze the genetic diversity and relationships among 31 Iranian walnut genotypes along with four foreign cultivars. The nut weight ranged from 7.52 to 17.73 g, kernel weight from 4.00 to 9.83 g, and kernel percentage ratio from 38.78 to 67.05% among studied genotypes. In SSRs analysis, nine primer pairs were tested that produced 39 alleles ranging from 2 to 8, with a mean value of 5.10 allele per primer. The Iranian genotypes showed relatively high diversity both for their SSRs loci and morphological traits. Although the foreign cultivars (‘Serr’, ‘Vina’, ‘Franquette’ and ‘Lara’) clustered with each other, they also laid close and within the Iranian genotype. The results of the study provided us with valuable diversity among our genotypes which could be used for breeding studies and also showed the power of genetic markers for analysis and evaluation of this diversity.     

梨品种资源遗传差异的RAPD分析

明确种质间的遗传差异,对杂交育种中亲本的选择和搭配具有重要意义。利用随机扩增多态性DNA(RAPD)技术,从40个随机引物中筛选出了33个多态性好的引物,在21个品种间进行了分析,最终得到339个清晰稳定的扩增位点,其中多态性位点为292个,占86.1%。利用UPGMA(非加权配对算术平均)法进行了品种间相似系数的计算以及聚类分析,揭示了这些品种间遗传上的差异程度。     

Variety identification and comparative analysis of genetic diversity in yardlong bean (Vigna unguiculata spp. sesquipedalis) using morphological characters,SSR and ISSR analysis

Genetic diversity and relatedness of 23 yardlong bean (Vigna unguiculata spp. sesquipedalis) accessions and 7 accessions of a hybrid between cowpea (V. unguiculata spp. unguiculata) and yardlong bean (dwarf yardlong bean) in Thailand were estimated using morphological characters, simple sequence repeat (SSR) and inter-simple sequence repeat (ISSR) markers. In addition, two mungbean (Vignaradiata (L.) Wilczek) and two blackgram (Vigna mungo (L.) Hepper) accessions were also used as outgroup species for molecular analysis. Five morphological characters were diverse among most accessions. However, five groups of 2–3 accessions could not be distinguished from one another based on these morphological characters alone. Unweighted pair-group arithmetic average (UPGMA) analysis of these characters separated these 30 accessions into 2 major groups; the yardlong bean group and the dwarf yardlong bean group. Eleven of the sixteen SSR primers yielded clear SSRs, ten of which were polymorphic (90.91% polymorphism), detecting a total of 54 alleles with an average of 4.91 alleles per locus. These 10 polymorphic SSR markers successfully distinguished 28 yardlong bean and dwarf yardlong bean accessions. The polymorphic information content (PIC) among genotypes varied from 0.251 to 0.752 with an average of 0.597. Among the 16 ISSR primers used, a total of 312 ISSR fragments were amplified for these three Vigna species, revealing the polymorphism percentage of 91.03%. The average ISSR PIC value (0.197) with the range of 0.137–0.276 was lower than that of SSR. Nevertheless, the average marker index of this multilocus marker was 3.495, which was higher than that of SSR (0.669), owing to the differences in the effective multiplex ratio. In addition, Mantel test cophenetic correlation coefficient was higher for ISSR (0.566) than that of SSR (0.198). These results indicated higher efficiency of ISSR for estimating the levels of genetic diversity and relationships among yardlong beans and dwarf yardlong beans in this study. Pair-wise coefficients of SSR- and ISSR-based genetic similarity among all yardlong bean and dwarf yardlong bean accessions averaged 0.87 and 0.91, respectively, suggesting a narrow genetic base that emphasizes the need to broaden genetic diversity to ensure continued breeding success. Clustering of genotypes within groups was not similar when SSR and ISSR derived dendrograms from UPGMA analysis were compared. It appeared that ISSR was the most effective marker system in determining the genetic variability and relationships among yardlong bean and dwarf yardlong bean accessions and differentiating three Vigna species. In addition, ISSR was also most useful for variety identification since all 30 yardlong beans and dwarf yardlong bean accessions can be effectively distinguished by only four ISSR primers with the highest PIC values.     

Analysis of genetic structure in a large sample of pomegranate (Punica granatum L.) using fluorescent SSR markers

Molecular markers are helpful to efficiently protect the plant breeders’ rights. Fluorescent simple sequence repeats (SSR) based on DNA sequencing is a powerful and automated platform for the detection of genetic polymorphism. Here, we first reported 13 SSRs using a fluorescent SSR panel according to the reference genome information, and detected the genetic diversity and population structure of 136 pomegranate varieties. The average number of alleles per locus was 6.31, gene diversity ranged from 0.16 to 0.37 with an average of 0.28, and polymorphic information content (PIC) varied from 0.14 to 0.29 with a mean value of 0.22. The mean genetic distance (GD) between varieties was 0.32. Population structure analysis divided the varieties into three different subpopulations (Q1, Q2, and Q3). The cultivars in Q1 all came from China, and almost all cultivars came from foreign countries combined with Chinese were grouped into Q2. The only accession originated from Myanmar was grouped to Q3. The results indicated that 13 SSR markers were polymorphic. The varieties originating from the same geographical region were more closely related, and extensive gene flow had taken place between the varieties from different regions. The results may be useful for the efficient selection breeding and variety protection.     

Molecular characterization and genetic relationship among almond cultivars assessed by RAPD and SSR markers

RAPDs and SSRs were used to study the genetic diversity of Iranian almond cultivars and their relationship to important foreign cultivars and three related species. Eight unidentified almond Shahrodi cultivars and three wild almonds (Prunus communis, Prunus orientalis and Prunus scoparia) were also included. Of the primers tested, 42 (out of 80) RAPD and 18 (out of 26) SSR primers were selected for their reproducibility and high polymorphism. A total of 664 polymorphic RAPD bands were detected out of 729 bands. The number of presumed alleles revealed by the SSR analysis ranged from 3 to 10 alleles per locus with a mean value of 6.64 alleles per locus. Both techniques discriminated the genotypes very effectively, but only RAPDs were able to discriminate the cultivars Monagha and Sefied. Results demonstrated an extensive genetic variability within the tested cultivars as well as the value of SSR markers developed in peach for characterization of almond and related species of Prunus. Dice similarity coefficient was calculated for all pair wise comparisons and was used to construct a UPGMA dendrogram. For both markers a high similarity in dendrogram topologies was obtained although some differences were observed. All dendrograms, including that obtained by the combined use of both the marker data, depicted the phenetic relationships among the cultivars and species, depending upon their geographic region and/or pedigree information. Almond cultivars clustered with accession of P. communis showing their close relationship. P. orientalis and P. scoparia were clustered out of the rest of P. dulcis.