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
The study was conducted to assess intraspecific variation/interrelationships and to determine the association of geographical distribution and phenotypic diversity in the Jatropha curcas accessions studied. Ex situ mo...The study was conducted to assess intraspecific variation/interrelationships and to determine the association of geographical distribution and phenotypic diversity in the Jatropha curcas accessions studied. Ex situ morphological characterization of 13 Jatropha curcas genotypes from various sources was undertaken using 21 quantitative traits. The generated data was subjected to two phenetic analysis methods （principal components analysis and cluster analysis）. Principal Components Analysis （PCA） reduced the collected data to 5 principal components that cumulatively explained 88.81% of total variance. PCA also subdivided the Jatropha provenances into distinct groups on the basis of height. The two clustering mechanisms, Average Linkage-Unweighted Pair Group Method with Arithmetic Mean （UPGMA） and Centroid Method （UPGMC）, divided the provenances into two major groups and revealed the divergence of Tubao-Philbio from the rest of the provenances. However, the study failed to adequately establish a relationship between spatial dispersal and phenotypic divergence in the Jatropha genotypes implying possible genetic homogeneity for the accessions studied. Screening for more quantitative traits and the use of more advanced molecular marker technologies are therefore recommended for a more accurate estimation of genetic diversity in Jatropha.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
基金国家自然科学基金(61640020)江苏省农业自主创新项目(CX(13)3054+5 种基金CX(16)1006)江苏省重点研发计划(BE2016368-1)江苏省科技重点及面上项目(SBE2018310371)弹总装线***技术研究(JCKY2017***)Postgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX17_0107)北京市教育委员会科技计划面上项目(KM201510028019)
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.
文摘The study was conducted to assess intraspecific variation/interrelationships and to determine the association of geographical distribution and phenotypic diversity in the Jatropha curcas accessions studied. Ex situ morphological characterization of 13 Jatropha curcas genotypes from various sources was undertaken using 21 quantitative traits. The generated data was subjected to two phenetic analysis methods （principal components analysis and cluster analysis）. Principal Components Analysis （PCA） reduced the collected data to 5 principal components that cumulatively explained 88.81% of total variance. PCA also subdivided the Jatropha provenances into distinct groups on the basis of height. The two clustering mechanisms, Average Linkage-Unweighted Pair Group Method with Arithmetic Mean （UPGMA） and Centroid Method （UPGMC）, divided the provenances into two major groups and revealed the divergence of Tubao-Philbio from the rest of the provenances. However, the study failed to adequately establish a relationship between spatial dispersal and phenotypic divergence in the Jatropha genotypes implying possible genetic homogeneity for the accessions studied. Screening for more quantitative traits and the use of more advanced molecular marker technologies are therefore recommended for a more accurate estimation of genetic diversity in Jatropha.
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.
