鱼腥草种质资源群体表型遗传多样性研究

本试验通过观测湖南怀化市不同地域鱼腥草居群,以揭示其变异规律和检测种质资源的遗传多样性状况,为其保护和利用提供依据.以湖南省怀化市的16份鱼腥草种质资源为材料,观测了其群体表型性状特征,并分析了这些表型性状的变异系数、遗传参数和遗传多样性.结果表明,鱼腥草种质资源的不同表型质量性状的频率不同,以绿色地上茎、白色地下茎和心形叶最具代表性.居群问各表型数量性状以地上茎的分枝数和鲜质量、地下茎的节间数、4-甲基-1-异丙基-3-环己烯-1-醇和2,4-甲基-3-环己烯基异丙醇变异较大,根的直径变异最小;而居群内以地上茎分枝数的变异系数最大(39.8%),甲基正壬酮含量最低(13.4%).居群内各表型数量性状多样性指数为0.182～0.710,而居群间为0.213～0.804;不同地域类群间表型多样性指数存在一定差异,黄岩地区最高(1.024),鸡公界地区最低(0.574).群体问的平均表型变异约占总变异的1/2而群体内的约占1/3,说明群体问变异是表型变异的主要来源;群体间表型分化最大的是地上茎的分枝数(77.04%),最小的是根的直径(51.88%).在5%的选择强度下数量性状的绝对遗传进度都较小(RGS%<40%)但遗传力均较大(h~2>50%).当遗传距离分别为2.0和1.5时,材料被聚为2类和3类,而且聚类首先是按地上部分的茎色,其次是按叶型,再次是以海拔高度,最后是以地域而划分的.群体表型变异丰富而且具有遗传分化程度较高.

Genetic Diversity of Populations in Germplasm Resources of Houttuynia cordata Thunb

The test wanted to post variation law and genetic diversity by studying different regional populations of Houttuynia cordata Thunb germplasm resources in Huaihua city of Hunan province, and supplied farther evidences for protection and utilization of resources. The differentiation coefficients and genetic parameter and diversity index analysis was applied on the population phenotypic traits of 16 germplasm resources of Houttuynia cordata Thunb from Huaihua city of Hunan Provinces. The frequency is different in the three quality traits which green overground stem,white underground stem and cordiform leaf were representative phenotypic quality traits. The variation coefficients of branch number and fresh weightiness of overground stem,the node number of underground stem,4-methyl-1-cypropyl-3-cyclohexoally-1-alcoholy and 2,4-methyl-3-cyclohexoallic cypropyl alcoholy between populations were the higher,whereas the variation coefficient of root diameter was the lowest ;but those of undecanone and branch number of overground stem per plant were lowest(13.4%)and highest respectively(39.8%)on the phenotypic traits within populations. The phenotypic diversity index between populations(0. 213 -0. 804)was relatively higher than that of within populations(0. 182 -0.710), the lowest in root number and the highest in underground fresh weightness ;the phenotypic diversity index of different geographic population was 0. 574 -1. 024 with the highest in Huangyan prefecture and the lowest in Jigongjie prefecture. The mean variation coefficients of between population accounted 1/2 whereas that of within population was 1/3 which the variations between populations were main variation source. The largest phenotypic differentiation coefficient between populations was the branch number of overground (77.04 %)whereas the smallest was root diameter(51.88 %). The absolute genetic advances were smaller (RGS% < 40%) but the heritabilitys were larger(h~2 > 50%)to the most quantity traits under 5% selection intensity. Cluster analysis based on morphological traits showed that the populations could be divided into two and three groups in genetic distance 2.0 and 1.5 respectively Which cluster in same kind was according as firstly color of overground stem, leaf shape next,altitude heigh again, region last. The differentiation coefficients were rich and the differentiation degree were high in populations.