AFLP, ISSR and RAPD markers reveal high levels of genetic diversity among Lupinus spp.

The Lupinus genus includes a number of important crop species. The use of defined nucleotide sequences for the analysis of genetic diversity among these species has revealed modest levels of diversity. The aim of this study was to access AFLP, ISSR and RAPD markers to evaluate the genetic diversity among L. albus, L. angustifolius, L. cosentinii, L. hispanicus, L. luteus, L. mutabilis, L. pilosus and L. polyphyllus. Unexpectedly, low levels of genetic similarity were found (ranging from 0.205 to 0.432), regardless of the type of molecular marker used. Nevertheless, these techniques consistently showed a greater genetic similarity between L. pilosus and L. cosentinii, L. mutabilis and L. polyphyllus and among L. luteus, L. hispanicus and L. angustifolius, clearly separating the Old World from the New World species. Such low genetic similarity among Lupinus spp. is most unlikely to be due to differences in coding sequences but could be the result of a long diverging process concerning non‐coding regions, which would represent a very important proportion of these genomes.     

我国不同生态类型桑树地方品种遗传多样性的ISSR分析

利用ISSR分子标记评价了我国不同生态类型的66个桑树地方品种的遗传多样性。12个ISSR引物总扩增条带数为83条,其中50条为多态性条带,多态性比例为60.24%,平均PIC值为0.146 9;平均遗传相似系数为0.845 6,8个生态群体间的遗传相似系数变异范围为0.844 1~0.964 0,不同地方品种间的遗传多样性存在差异。根据ISSR标记遗传相似系数,按UPGMA法对66个地方桑树品种进行聚类分析,聚类结果与生态型有一定相关性。研究结果提示:保护不同生态类型的桑树群体,对丰富桑树种质资源具有重要意义。     

24个白桑(Morus alba L.)地方品种的遗传多样性分析

采用ISSR分子标记技术对山东、河北地区的24个白桑(Morus alba L.)地方品种资源进行了遗传多态性分析。筛选的13条ISSR引物共扩增86条扩增带,其中多态性条带63条,多态性比率为73.25%,ISSR标记遗传相似系数范围在0.6706~0.9529。通过类平均聚类(UPGMA)法分析,24份材料聚分为2大类。     

A comparative analysis of the genetic diversity between inbred lines of Zinnia elegans using morphological traits and RAPD and ISSR markers

Genetic diversity within Zinnia elegans is key to the genetic improvement of this important ornamental species. Here, morphological traits and RAPD and ISSR molecular markers were used to assess levels of polymorphism across 20 inbred lines. Thirty-four morphological traits were scored and also 147 RAPD marker-fragments, as amplified by 12 arbitrary primers, and 128 ISSR marker-fragments as generated by 9 primers. The number of polymorphic loci, the percentage of polymorphic loci, Shannon's Information index (I) and the effective number of alleles (Ne) were calculated from the RAPD data as 100, 68.03%, 0.3559 and 1.4169, respectively. From the ISSR data, these respective statistics were calculated as 97, 76.38%, 0.4013 and 1.4728. Thus, ISSR markers were considered slightly superior to RAPD markers for assessing genetic diversity between the accessions; however, Mantel's test indicated significant correlation (R = 0.733) of the RAPD and ISSR results. By contrast, the morphological matrix showed low correlation with both RAPD and ISSR data matrices (R = 0.3814 and 0.3765, respectively). Cluster analysis showed that groupings of the accessions according to all three methods correlated well with their geographic region of origin, but flower color was not strongly associated with the genetic classification of these inbred lines of Z. elegans.     

Genetic diversity and relationships of lotus (Nelumbo) cultivars based on allozyme and ISSR markers

Genetic diversity and genetic relationships of lotus (Nelumbo Adanson) cultivars were evaluated using allozyme and ISSR markers. The samples used covered 11 accessions of possible hybrids between Nelumbo nucifera and Nelumbo lutea and 92 accessions of N. nucifera including 69 flower lotus, 13 rhizome lotus, 5 seed lotus and 5 wild lotus. For allozyme studies, a total of 31 alleles at 23 loci of 18 enzyme systems were detected of which 5 (21.7%) loci Aat, Idh, Mdh-2, Pgd, Sod were polymorphic. The loci of Aat and Idh included two alleles, Mdh-2, Pgd and Sod included three alleles. Eighteen genotypes were detected with the 13 alleles of the 5 polymorphic loci. The parameters of average allele number, observed heterozygosity, expected heterozygosity and Shannon information index of 92 N. nucifera samples were 1.35 ± 0.71, 0.06 ± 0.21, 0.05 ± 0.14, 0.10 ± 023, respectively. Thirteen ISSR primers generated 93 loci, of which 37.63% were polymorphic across all samples. The percentage of polymorphic loci, average allele number, expected heterozygosity and Shannon information index of 92 N. nucifera samples were 26.67%, 1.30 ± 0.46, 0.10 ± 0.18 and 0.15 ± 0.25, respectively for the ISSR data. The ‘Bottleneck effect’ and rapid propagation of clones after the ice ages may explain the low genetic diversity of lotus. The dendrograms based on ISSR and allozymes were not congruent. Based on the ISSR data, the 103 samples were divided into the N. nucifera group (Group I), and the group containing inter-specific hybrids between N. nucifera and N. lutea (Group II). The flower lotus, rhizome lotus, and seed lotus each has multiple sources of origin. Plant size, a criterion commonly used in the classification of cultivars of lotus, is not correlated with genetic variation. Flower color is correlated with the cultivar classification to some degree, but its variation is complex in the hybrids.     

茉莉花ISSR-PCR反应体系的建立

以茉莉花为材料,研究了PCR反应体系的主要成分及退火温度对茉莉花ISSR扩增结果的影响.结果表明:在20μL的反应体中,Mg2 的用量为1.2～1.6 mmol/L,dNTPs 浓度为0.15 mmol/L,引物的浓度为0.5μmol/L,Taq DNA 聚合酶的用量为1U,模板DNA的用量为40～70 ng,在48～50℃的退火温度下40个循环,能得到清晰、多态性高的ISSR带谱.     

木菠萝ISSR反应体系的建立和优化

以木菠萝为材料,研究了模板DNA、Taq DNA聚合酶、引物、Mg2+ 及dNTPs浓度对ISSR-PCR扩增结果的影响,得出木菠萝ISSR的较佳反应体系为:在20μI反应体系中DNA模板1.6 ng·μI-1,Taq DNA聚合酶1.25 U·(20μl)-1,引物0.24 μmol·L-1,dNTPs 0.2 mmol-1 ,Mg2+ 2 mmol· L-1,10×PCR缓冲液2.0μl.     

Molecular characterisation of coconut (Cocos nucifera L.) varieties using ISSR and SSR markers

The present study was carried out to standardise a DNA isolation protocol for coconut and to characterize five coconut varieties using 18 inter-simple sequence repeat (ISSR) and 14 simple sequence repeat (SSR) markers. DNA was extracted from tender young leaf samples collected from the fronds of five different trees of each coconut variety. A protocol using 0.095 g ml^?1 glucose, 0.025 g ml^?1 polyvinylpyrrolidone, 0.0045 g ml^?1 sodium bisulphite, 0.0055 g ml^?1 sodium dodecyl sulphate, and 50 µl ml^?1 sarcosine produced good quality DNA. The average polymorphism percentages revealed using ISSR or SSR markers between the five varieties were 31.9% or 92.9%, respectively. Using ISSR markers, the overall similarity between all five varieties ranged from 0.657 to 0.775, whereas it was 0.037–0.304 using SSR markers. The levels of polymorphism detected using ISSR markers among the five samples each of ‘Banawali’, ‘Gangabondum Green Dwarf’, ‘Pratap’, ‘Konkan Bhatye Coconut Hybrid-I’, and ‘East Coast Tall’ were 23.2%, 24.2%, 25.6%, 27.1%, and 21.2%, respectively. The levels of polymorphism detected using SSR markers among the five samples of the same five varieties were 85.7%, 86.9%, 85.7%, 100%, and 92.9%, respectively. This study indicated that genetic variation existed both between and within samples of each of the five varieties of coconut. SSR markers were superior to ISSR markers. The extent of genetic variation obtained within a variety was not expected, so it is essential to maintain seed purity via artificial pollination.     

凤尾桑及其芽变品系间遗传变异的ISSR分析

利用ISSR引物,从分子水平分析了凤尾桑及其芽变株系的遗传变异。从8个ISSR引物扩增结果来看,3个引物的扩增产物在株系间无差异,从变异株系扩增条带来看,凤尾芽变变异最大。本结果从分子水平证明了芽变株系的遗传结构差异。     

莲雾种质资源遗传多样性的ISSR分析

 对12份莲雾资源和2个莲雾近缘种进行了ISSR分析, 18条引物共扩增出459个位点, 其中多态性位点435个(94.77% ) 。利用UPGMA聚类分析表明: 蒲桃、马六甲蒲桃与莲雾分属于3个不同的组; 12个莲雾品种和品系又分成4个亚组, 这与传统分类学上按照果实成熟期的划分结果基本一致。