为了解决传统不加权算术平均组对方法(unweighted pair group method with arithmetic mean,简称UPG- MA)存在的'tie trees'问题,通过改进UPGMA,提出了不加权算术平均组群方法(unweighted multiple group method with arithmeti...为了解决传统不加权算术平均组对方法(unweighted pair group method with arithmetic mean,简称UPG- MA)存在的'tie trees'问题,通过改进UPGMA,提出了不加权算术平均组群方法(unweighted multiple group method with arithmetic mean,简称UMGMA),从理论和应用上证明了UMGMA能产生唯一的进化树,并且在UPGMA树唯一时,UMGMA树和UPGMA树在不计分支次序时完全相同,解决了UPGMA树的唯一性问题.与UPGMA不同之处在于,UMGMA反复利用极大紧邻子树上的顶点把多个距离最近的种群进行合并,因此在UPGMA产生的二叉树不唯一时,UMGMA能产生一棵具有唯一拓扑结构的多叉树.通过适当选择大于0的容差参数,UMGMA还可以在不同的宏观层次上产生容差进化树,以突出物种较多时进化树的整体脉络.展开更多
目的利用SCoT标记对47份栀子种质资源的亲缘关系及遗传多样性进行了研究。方法采用NTSYS version 2.1软件计算遗传相似性系数,利用UPGMA法构建聚类树状图。结果从36条引物中筛选出20条多态性丰富的引物对供试材料进行PCR扩增,共获得154...目的利用SCoT标记对47份栀子种质资源的亲缘关系及遗传多样性进行了研究。方法采用NTSYS version 2.1软件计算遗传相似性系数,利用UPGMA法构建聚类树状图。结果从36条引物中筛选出20条多态性丰富的引物对供试材料进行PCR扩增,共获得154条谱带,其中多态性条带120条,多态性条带所占的比率(PPL)达78.14%,Nei-Li相似系数(GS)在0.655 8~0.980 5,平均值为0.784 1;聚类结果显示栀子遗传多样性丰富且亲缘关系复杂。结论研究表明SCoT标记技术可以很好地应用于栀子种质资源的遗传多样性分析,研究结果可为栀子育种、分类、保存和利用提供可靠的理论依据。展开更多
In this study, the genetic diversity of 51 cultivars in the primary core collection of peach （Prunus persica （L.） Batsch） was evaluated by using simple sequence repeats （SSRs）. The phylogenetic relationships and...In this study, the genetic diversity of 51 cultivars in the primary core collection of peach （Prunus persica （L.） Batsch） was evaluated by using simple sequence repeats （SSRs）. The phylogenetic relationships and the evolutionary history among different cultivars were determined on the basis of SSR data. Twenty-two polymorphic SSR primer pairs were selected, and a total of 111 alleles were identified in the 51 cultivars, with an average of 5 alleles per locus. According to traditional Chinese classification of peach cultivars, the 51 cultivars in the peach primary core collection belong to six variety groups. The SSR analysis revealed that the levels of the genetic diversity within each variety group were ranked as Sweet peach 〉 Crisp peach 〉 Flat peach 〉 Nectarine 〉 Honey Peach 〉 Yellow fleshed peach. The genetic diversity among the Chinese cultivars was higher than that among the introduced cultivars. Cluster analysis by the unweighted pair group method with arithmetic averaging （UPGMA） placed the 51 cultivars into five linkage clusters. Cultivar members from the same variety group were distributed in different UPGMA clusters and some members from different variety groups were placed under the same cluster. Different variety groups could not be differentiated in accordance with SSR markers. The SSR analysis revealed rich genetic diversity in the peach primary core collection, representative of genetic resources of peach.展开更多
文摘为了解决传统不加权算术平均组对方法(unweighted pair group method with arithmetic mean,简称UPG- MA)存在的'tie trees'问题,通过改进UPGMA,提出了不加权算术平均组群方法(unweighted multiple group method with arithmetic mean,简称UMGMA),从理论和应用上证明了UMGMA能产生唯一的进化树,并且在UPGMA树唯一时,UMGMA树和UPGMA树在不计分支次序时完全相同,解决了UPGMA树的唯一性问题.与UPGMA不同之处在于,UMGMA反复利用极大紧邻子树上的顶点把多个距离最近的种群进行合并,因此在UPGMA产生的二叉树不唯一时,UMGMA能产生一棵具有唯一拓扑结构的多叉树.通过适当选择大于0的容差参数,UMGMA还可以在不同的宏观层次上产生容差进化树,以突出物种较多时进化树的整体脉络.
基金Supported by Beijing Municipal Education Commission Urban Agriculture Disciplines Development Project (XK1001900553)Program for new Century Excellent Talents in University of China (NCET-06-0108).
文摘In this study, the genetic diversity of 51 cultivars in the primary core collection of peach （Prunus persica （L.） Batsch） was evaluated by using simple sequence repeats （SSRs）. The phylogenetic relationships and the evolutionary history among different cultivars were determined on the basis of SSR data. Twenty-two polymorphic SSR primer pairs were selected, and a total of 111 alleles were identified in the 51 cultivars, with an average of 5 alleles per locus. According to traditional Chinese classification of peach cultivars, the 51 cultivars in the peach primary core collection belong to six variety groups. The SSR analysis revealed that the levels of the genetic diversity within each variety group were ranked as Sweet peach 〉 Crisp peach 〉 Flat peach 〉 Nectarine 〉 Honey Peach 〉 Yellow fleshed peach. The genetic diversity among the Chinese cultivars was higher than that among the introduced cultivars. Cluster analysis by the unweighted pair group method with arithmetic averaging （UPGMA） placed the 51 cultivars into five linkage clusters. Cultivar members from the same variety group were distributed in different UPGMA clusters and some members from different variety groups were placed under the same cluster. Different variety groups could not be differentiated in accordance with SSR markers. The SSR analysis revealed rich genetic diversity in the peach primary core collection, representative of genetic resources of peach.
