红棕杜鹃不同海拔种群的表型多样性研究

摘要

In order to reveal the phenotypic diversity and variation pattern of Alpine Rhododendron species, we measured 12 phenotypic traits of Rhododendron rubiginosum natural populations at five different alti-tudes in Jiaozi Mountain National Natural Reserve of Yunnan Province and studied the levels of phenotypic diversity by using ANOVA analysis,correlation analysis and cluster analysis.The results indicated that:(1)there were significant differences in phenotypic variations among and within populations.Coefficient of variation (CV)of these traits ranged from 8.51% to 34.32%,and RHL (R′)ranged from 38.04% to 100%.High phenotypic variations were occurred in the relative low elevation populations (P1 and P2), while low degree of variations occurred in the moderate and high elevation populations (P3、P4 and P5). (2)Based on the Shannon-Weaver diversity index (H′)analysis,the mean phenotypic diversities index of 5 sample elevation populations was 2.4534,and the mean phenotypic diversity index of 12 phenotypic traits was 4.0763.It indicated that there were richness phenotypic diversity in R.rubiginosum popula-tions.(3 )The correlation analysis showed that there were significant correlations among these traits. There were significant negative correlations between elevation and FSL and IW.However,there was no significant correlation between elevation and other traits.(4)The 5 sampled populations of R.rubiginosum could be divided into two groups according to the UPGMA cluster analysis.Therefore,the trait variations of natural populations at different altitudes were affected mainly by micro-environmental heterogeneity of different R.rubiginosum populations.%为了揭示高山杜鹃群体在不同海拔梯度上的表型变异程度和变异规律,以云南轿子山国家级自然保护区天然分布的5个海拔梯度红棕杜鹃种群为研究对象,通过对其12个性状的测量,分析不同海拔梯度下红棕杜鹃种群的表型多样性.结果表明:(1)调查的12个性状中5个存在显著差异,占总表型性状的41.67%;各性状变异系数(CV)的大小分布在8.51%~34.32%之间;相对极差(R′)分布在38.04%~100%之间,低海拔种群(P1和P2)的表型性状变异丰富、极端变异高,而中、高海拔种群(P3、P4、P5)的表型性状变异和极端变异程度较低.(2)Shan-non-Weaver多样性指数分析表明,轿子山红棕杜鹃不同海拔种群存在丰富的表型多样性,5个海拔种群的平均表型多样性指数为2.4534,12个表型性状的平均多样性指数为4.0763.(3)相关性分析表明,花序宽和花柄长与海拔呈显著负相关,其它性状与海拔相关性并不显著.(4)聚类分析表明,红棕杜鹃不同海拔种群可以聚为明显的2支.研究认为,轿子山自然保护区红棕杜鹃不同海拔种群的环境异质性是影响其表型变异的主要因素.