基于种实性状的无患子天然群体表型多样性研究

无患子(Sapindus mukorossi Gaertn.)是我国长江以南地区传统的重要绿化树种,其果皮富含皂苷,种仁富含油脂,是国家林业局审定的新型木本油料树种之一。为揭示无患子群体间和群体内种实表型性状变异式样,采用单因素方差分析、巢式方差分析、相关分析和主成分分析等方法,对无患子13个天然群体的10个种实表型性状进行比较分析,研究其群体间和群体内种实表型多样性以及表型变异与地理生态因子间的相关性。结果表明:无患子种实表型性状变异系数平均为7.34%,在群体间和群体内均存在丰富的表型变异。表型性状分化系数平均为62.21%,群体间变异(39.93%)大于群体内(27.46%),是无患子种实表型性状变异的主要来源。多数性状在群体间差异显著,不同程度的表现出边缘群体易于分化的特点,但地理变化规律不连续,而在群体内不同性状的差异性亦不一致。种子形态受群体地理生态的影响较果实形态大,西北部群体种子趋于椭圆形,东部、南部则趋于圆球形;地理纬度、年平均气温与多数种实性状间呈显著相关,是无患子种实表型性状变异的主要地理生态影响因子。可见,无患子种实表型性状在群体间、群体内变异都较为丰富,这些变异是由遗传和环境因素共同作用的结果。群体间和群体内多层次的变异为无患子优良种质资源保育和利用提供了物质基础。

Phenotypic diversity in natural populationsof Sapindus mukorossi based on fruit and seed traits

Sapindus mukorossi Gaertn is a traditional and important virescencetree species in the south part of China with rich saponins in peel and rich oil in seed. This tree specie is one of the newly-developed woody oil species that were approved by the State Forestry Administration of China. The objectives of the present study were investigating phenotypic variation of 10 fruit and seed traits among 13 natural populations of S. mukorossi and disclosing the relationship between phenotypic variation and geographical factors. Variance analysis, multiple comparison, correlation analysis and principal component analysis were used to examine morphological diversity among and within populations based on data of 10 phenotypic traits. Results showed significant variation in fruit and seed traits within and among populations. The degree of variation in the 10 traits was significantly higher among populations than that within populations. The averaged coefficient of variation (CV) for the 10 traits was 7.34%. The mean phenotypic differentiation coefficient for the 10 traits was 62.21%, and the variation within populations (27.46%) was lower than that among populations (39.93%), indicating that variance among populations was the main source of the phenotypic variation in S. mukorossi. There were significant difference in most traits among populations, and most traits exhibited larger degree of differentiation in the marginal populations. Geographically continuous variation was not detected, and the differentiation of most traits were not consistent within the populations. Seed morphology was largely influenced by ecological factors of populations. The seed morphology in northwest area is near oval, whereas the seed morphology in eastern and southern area is near sphericity. Altitude and annual average temperature were significantly corelated with major traits of fruit and seed, idicating that altitude and annual average temperaturethe were the main genographical and ecological factors and they interactively contribute to variations of fruit and seed phenotypic traits among populations and within populations. The multiple variations among and within populations provided insights and guidelines for genetic conservation and utilization of S. mukorossi germplasm resources.