岷江柏天然种群种实表型变异特征

运用巢式方差分析、变异系数、表型分化系数和聚类分析等多种分析方法,研究了11个岷江柏种群的13个种实表型性状在种群内和种群间的变异及其与环境因子间的关系,并对其进行了类群划分.结果表明: 岷江柏种实表型性状在种群间和种群内均存在显著差异,种群内的变异(49.7%)大于种群间的变异(28.6%),种间平均分化系数为43.4%,分化程度相对较大.球果质量的平均变异系数最高(37.2%),其次是单个球果种子质量,球果长的平均变异系数最小(8.0%),是最稳定的种实性状.康定县的表型多样性最丰富,武都县的最小.在岷江柏的研究区内,最热月的平均气温和生长季的水分条件是其种实表型的主要限制因子.依据13个种实表型性状将11个岷江柏天然种群分为2类3亚类,基本上代表了3个流域的种群分布情况.大渡河流域种群种实表型性状最佳,岷江流域最差.

Phenotypic variations in cones and seeds of natural Cupressus chengiana populations in China

A total of 13 phenotypic traits from 11 natural populations of Cupressus chengiana were investigated by using nested analysis, variation coefficient, phenotypic traits differentiation coefficient, and un-weighted pair-group method by arithmetic averages (UPGMA) cluster analysis. Phenotypic variations among and within populations of C. chengiana were discussed, the relationship among phenotypic traits and that between phenotypic traits and environmental factors were analyzed, and the 11 populations were divided. The results showed that there was significant difference in phenotypic variation both between and within populations. Variation within populations (49.7%) was greater than that between populations (28.6%). The mean coefficient of phenotypic differentiation between populations was 43.4% suggesting the differentiation between populations was relatively larger. The average variation coefficient of cone mass was the highest (37.2%), followed by seed mass in single cone, and that of cone length was the smallest (8.0%) indicating the cone length was the most stable phenotypic trait. The phenotypic diversity was greatest in Kangding County and smallest in Wudu County. The mean annual temperature of the hottest month and mean annual precipitation of growing season were the main environmental factors on phenotypic diversity in cones and seeds of C. chengiana in the study region. According to the 13 phenotypic traits, the 11 populations could be divided into two groups and three subgroups, which showed how C. chengiana distributed in three watersheds. Phenotypic traits in cones and seeds of C. chengiana populations were the best in Daduhe River watershed, and those were the worst in Minjiang River watershed.