广西野生杨梅资源遗传多样性的ISSR分析

广西杨梅资源十分丰富。为了准确了解和掌握广西野生杨梅资源类型,利用ISSR技术对广西野生杨梅资源的分类和遗传多样性进行了探讨。从116条ISSR引物中筛选出12条引物,对40份杨梅样品进行ISSR-PCR分析。结果显示,共扩增出154条DNA条带,其中多态性条带113条,占73.38%,表明广西杨梅资源遗传多样性非常丰富。用NTYS-PC2.1软件进行UPGMA聚类分析,可将供试杨梅样品分为4大类:它们分别代表杨梅、大叶青杨梅、毛杨梅、青杨梅,其中大叶青杨梅的形态分类和ISSR分子分类存在很大的差异。     

平菇ISSR遗传多样性分析

以53个平菇菌种为试材,采用ISSR标记技术,对采自多地的平菇材料进行遗传多样性检测,以期为平菇优良品种选育和亲缘关系的研究提供分子生物学依据。结果表明:从27个ISSR引物中共筛选出14个多态性明显的引物;在53份供试材料中共扩增出189条谱带,其中多态性条带189条,多态性为100%;材料间遗传相似系数范围在0.44~0.99,聚类分析结果显示,在0.62水平上53株菌株分为8组,多数菌株之间遗传相似性较低。这表明供试菌株在DNA水平上存在比较显著的遗传变异和丰富的遗传多样性;同时发现供试材料间的聚类与地域无明显相关性。     

椰子ISSR遗传多样性分析

应用ISSR技术分析了来自多个国家的30份椰子品种或类型的遗传多样性。用29条多态性较好的引物共扩增出了157条条带,其中多态性条带110条,多态性比率70%;用NTSYS软件计算出这30份材料的DICE相似系数在0.548～0.962,平均值为0.788。其中相似系数最高的是红矮(14号)和杂交种(16号)为0.962,最低的是海南高种(29号)和斐济高种(5号)仅0.548。用UPGMA方法构建聚类树,所有材料在相似系数0.79处被划分为三大类(类群A,B,C)。A类群包括所有引进的高种、矮种和杂交种,B类群包含了除雄树以外的所有特殊变异类型椰子,而来自海南的所有高种单独聚为C类。综合研究结果表明我国海南的椰子种质资源多样性水平不高,需要进一步引进国外优良种质。     

地木耳遗传多样性的ISSR分析

采用ISSR分子标记技术对7个居群的地木耳进行了遗传多样性研究。结果表明:8条ISSR引物共检测到41条清晰的谱带,其中,多态性条带40条;地木耳在物种水平上遗传多样性较高,其PPB为97.56%、He为0.411 4、I为0.598 1;在居群水平上遗传多样性相对较低,其PPB为43.90%、He为0.165 4、I为0.246 3;居群间遗传变异较高,其中,Gst为0.597 3,PHIst为0.613 4,(Hsp-Hpop)/Hsp为0.588 2;聚类分析发现,以遗传一致度0.72为标准,7个地木耳居群可分为4类。地木耳物种水平遗传多样性大于居群水平,居群间遗传变异大于居群内。     

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。     

菠萝蜜遗传多样性的ISSR分析

用ISSR标记方法对76份菠萝蜜(Artocarpus heterophyllus Lam.)种质资源DNA的遗传多样性进行了检测,24个引物共检测到477条带,其中427条具多态性(占89.52%),平均PIC为0.23,24个引物能把76份种质完全区分开来。遗传距离分析结果显示供试种质的遗传多样性较低,在DNA水平上的遗传相似系数为0.626～0.945,平均为0.775。聚类分析表明,76份菠萝蜜材料在遗传距离系数为0.752处可分为4大类,其中热带植物园的种质WJ2和GSYWJ1与其他种质的遗传距离相对较大,干胞和湿类型不能独立聚类。另外各地区的种质与雷州半岛种质明显分开聚类,而雷州半岛各地区的种质混杂聚类在一起,不能按地区单独聚类。     

辐射八宝景天ISSR遗传多样性分析

为研究辐射所得八宝景天植株的遗传多样性,采用ISSR分子标记技术对0、30、50 Gy 3个梯度辐射所得的6株八宝景天突变体的亲缘关系进行分析,以确定突变体之间的遗传差异。结果表明:23条ISSR引物能在6个植株间扩增出175条谱带,其中127条是多态性谱带,多态率高达72.57%,表现出了较高的多态性。从聚类树状图中可以看出,6个植株间的相似系数在0.5805~0.7886,平均相似系数为0.6846,对照植株和辐射植株有一定的差异性。随着辐射剂量的增大,遗传距离增大,相似系数减小,相应的变异系数增大。     

镰刀菌属遗传多样性的ISSR分析

对运用分子生物学手段研究镰刀菌属的遗传多样性进展进行了综述,并对ISSR分子标记技术在镰刀菌属遗传多样性方面的应用前景作出了分析与展望。     

野生天门冬遗传多样性的ISSR分析

通过ISSR技术对19个野生天门冬居群共67个个体进行遗传多样性分析.结果表明:用13个随机引物共扩增出125条清晰条带,其中92条具多态性,平均多态性位点比率为73％,建立了不同居群的ISSR标记;Nei's基因多样性指数H=0.19,Shannon,s多样性指数I=0.30,遗传分化指数Gst=0.8206.聚类分析表明,青海、云南和贵州省的5个居群聚为一大支,其它居群为另一大支.野生天门冬种内具有较高的遗传多样性,遗传变异主要存在于居群间;ISSR标记可以作为研究天门冬遗传多样性及居群鉴定的有效标记.     

佛手种质资源遗传多样性的ISSR 分析

 收集佛手（Citrus medica L. var. sarcodactylis Swingle）13 份、枸橙（C. medica var. yunnanensis Ding）1 份及香椽（C. medica L.）6 份,共20 份种质资源,其中14 份成功引种在佛手资源圃。在对其中 14 份资源生物学特性进行描述的基础上,采用ISSR 分子标记技术对20 份样品进行遗传多样性分析。筛 选出的11 条引物共检测到102 条DNA 条带,其中58 条为多态性条带,多态性条带比率为56.9%。各样 品之间的遗传相似性系数在0.608 ~ 0.990 之间。聚类分析结果表明,当遗传系数为0.798 时,可将供试材 料分为枸橙、香橼和佛手3 个类群,新发现的3 个芽变材料是佛手中一个新的类群。     

广西龙虎山自然保护区龙荔种群生命表分析

 以广西龙虎山自然保护区龙荔种群为调查对象,编制其静态生命表,进行种群生存分析。通过绘制亏损率曲线、存活曲线、死亡率曲线、生存函数曲线,分析种群数量及动态变化。结果表明：该龙荔种群存活曲线趋于Deevey-Ⅰ型,种群的存活率呈单调减少,相应的积累死亡率呈单调增加,其下降或增加的幅度是前期大于后期。种群生长过程中在第Ⅳ龄级存在一个死亡高峰。说明在自然保护的情况下龙荔种群的生存状况仍然严峻,需适当进行人为护理并加强资源调查,对优良种质进行异地保护。     

石榴种质资源遗传多样性及亲缘关系的ISSR分析

利用ISSR标记技术对47个石榴品种遗传关系进行了分析。筛选出多态性高的6条ISSR引物,共扩增出120条DNA条带,其中多态性带109条,多态性百分率为90.83%,有效等位基因数(Ne)、Nei’s基因多样(H)、Shan-non信息指数(I)分别为1.294 5±0.309 4、0.189 7±0.161 8、0.309 1±0.219 8,遗传距离(Dg)变异为0.075 0～0.400 0,表明石榴品种间存在比较丰富的遗传多样性。利用UPGMA法构建分子树状图,将47个石榴品种分为5个类群。同时检测到15条特异性条带,可用于供试石榴中的11个品种鉴定的参考性标记。     

我国南方长茄种质资源的ISSR标记分析

从分子水平用ISSR标记法对南方长茄资源的遗传多样性进行分析,从100个ISSR引物中共筛选出12个多态性明显、条带清晰、反应稳定的引物,对57个样品DNA共扩增出116条谱带,平均每个引物扩增出9·67条带,其中多态性位点84个(71%)。品种间遗传相似系数在0·51~0·98之间,表明茄子栽培种内品种间的遗传基础相对较狭窄。利用UPGMA聚类分析,能将57个南方长茄品种划分为6个类群,类群的划分与地方来源没有很大的关系。     

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.     

Genetic structure of mulberry from different ecotypes revealed by ISSRs in China: An implications for conservation of local mulberry varieties

Mulberry is a perennial and economically important plant that has traditionally been used for feeding the silkworm. Evaluating genetic relationship is important for long-term improvement in mulberry yield, quality and resistance, and for germplasm conservation and identification. Population structure and genetic diversity of 8 mulberry populations from different ecotypes in China were analyzed by ISSR markers. Twelve ISSR primers generated a total of 83 amplification products, of which 50 were polymorphic, revealing 60.24% polymorphism among 66 mulberry local varieties, the mean PIC value was 0.1469. The total heterozygosity (H_T), heterozygosity within population (H_S), diversity between populations (D_ST) were 0.1600, 0.0851 and 0.0749, respectively. The coefficient of population differentiation (G_ST) was 0.4683, indicating that the variations among populations and those within populations contributed 46.8% and 53.2% to the total heterozygosity, respectively. The gene flow (N_m) was 0.5678, suggesting that genetic drift between populations can caused local genetic differentiation and therefore, population divergence. The mean genetic similarity coefficient was 0.8456, genetic similarity coefficient among 8 mulberry populations ranged from 0.8441 to 0.9640, indicating that genetic diversity of different populations existed variation. A dendrogram of all 66 local varieties of mulberry based on the genetic similarity using ISSR markers was generated by UPGMA cluster method. In the dendrogram, most varieties from the same ecotype clustered together.     

Genetic diversity and phylogenetic relationships of Prunus microcarpa C.A. Mey. subsp. tortusa analyzed by simple sequence repeats (SSRs)

Prunus microcarpa C.A. Mey. subsp. tortusa is a deciduous shrub well adapted to severe winter and dry-hot summer conditions. As the first step to explore the genetic and horticultural potential of P. microcarpa C.A. Mey. subsp. tortusa, we used SSRs to elucidate the genetic variation within its populations dispersed in upper Mesopotamia. We also investigated its phylogenetic relationship with economically important Prunus species; almond, apricot, sweet cherry, peach and plums. Using 47 amplifying SSR primer pairs, 63 P. microcarpa C.A. Mey. subsp. tortusa genotypes sampled from five locations and 15 cultivars belonging to other Prunus species were assayed. The cross-species transportability of SSRs was 96% indicating a high degree of homology between P. microcarpa C.A. Mey. subsp. tortusa and the other Prunus species. The genetic distance between P. microcarpa C.A. Mey. subsp. tortusa genotypes belonging to a particular geographic site was lower than that between genotypes of different geographic origins. Cluster analysis differentiated P. microcarpa C.A. Mey. subsp. tortusa genotypes according to their geographic sites and separated them from the other Prunus species. P. microcarpa C.A. Mey. subsp. tortusa and sweet cherry, the subgenus Cerasus, were located in the same major cluster, the other Prunus species, belonging to the subgenera Amygdalus and Prunus, were located in another one. The analysis of molecular variance (AMOVA) revealed that genetic variation among individuals within populations (59.10%) was much higher than among Prunus groups (29.28%) and among P. microcarpa C.A. Mey. subsp. tortusa populations of different geographic sites (11.61%). The results indicate a substantial genetic diversity in P. microcarpa C.A. Mey. subsp. tortusa and the need of exploring a wider area to increase the chance of finding a particular genotype.     

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。