带叶兜兰5个野生居群表型多样性分析

Phenotypic DiversityAnalysis of Five Wild Paphiopedilum hirsutissimum Populations

以云南、广西、贵州的5个带叶兜兰主要野生居群分布区为研究对象,采用巢式方差分析、表型分化系数、主成分分析、相关分析、聚类分析等分析方法,对带叶兜兰的18个性状的表型多样性进行分析。结果显示:带叶兜兰表型性状在居群间表现出显著或极显著差异,居群内变异较少。带叶兜兰平均表型分化系数为75.18%,居群间的变异是居群多样性的主要来源;18个表型性状变异系数平均值的变化范围为6.36%~18.51%,离散程度较高。主成分分析表明,造成带叶兜兰表型变异的主要来源是株高、子房长、花茎高、最大叶长、花横径和合萼片长6个性状。Pearson相关分析表明,株高、合萼片宽和中萼片宽等与大部分性状均呈显著或极显著正相关;18个性状中只有合萼片长与地理因子极显著相关。聚类分析结果表明,5个居群大致依据地理距离聚为3个类群。本研究发现,带叶兜兰居群遗传多样性较高,居群间的变异远高于居群内的变异,因此,应尽可能保护更多的野生居群,在原地保护的基础上建立种质资源保存圃、库,进行人工繁殖和育种,以利用促保护。

In this study,we investigated the phenotypic diversity of 18 characters on five main natural populations of Paphiopedilum hirsutissimum(Lindl. ex Hook. f.) Stein that were collected from three provinces Yunnan,Guangxi and Guizhou in China. The statistical methods used included nested variance analysis,coefficient of variation,correlation analysis,principal component analysis(PCA) and cluster analysis. The results revealed significant difference at most phenotypic traits among populations if compared to that within populations. The mean phenotypic differentiation coefficient(VST) was 75.18%,indicating that the population diversity was largely contributed by the variation among populations. The average variation coefficient of the 18 phenotypic traits was variable from 6.36%–18.51%,with a higher degree of dispersion. PCA showed that plant height,length of ovary,scape height,length of maximum leaf,diameter of flower and length of synsepal were the main sources of phenotypic variation. Pearson correlation analysis showed that plant height,width of synsepal and width of dorsal sepal were significantly or extremely significantly positively correlated with the majority of plant traits,whereas only the length of synsepal was extremely significantly correlated with geographic factors. Cluster analysis revealed three groups from the five populations,which could be explained by the geographic distribution. This study found that populations of Paphiopedilum hirsutissimum(Lindl. ex Hook. f.) Stein have high genetic diversity,and the variation between populations is much higher than that within the population. The phenotypic diversity indicates that wild Paphiopedilum hirsutissimum(Lindl. ex Hook. f.) Stein populations should be protected as much as possible. Moreover,it is recommended that germplasm is preserved in nurseries and libraries in addition to in-situ conservation,and that an artificial reproduction system is established enhance our conservation efficiency.