茶条槭自然种群种子和果实表型多样性研究

Phenotypic diversity of seeds and fruits in natural populations of Acer ginnala in China

关键词:  茶条槭, 种群, 种子和果实性状, 表型多样性, 变异, 地理生态因子

Key words:  Acer ginnala, population, fruit and seed traits, phenotypic diversity, variation, geographical ecologial factors

摘要:

为探析茶条槭(Acer ginnala)种子和果实表型差异程度及变异规律,该研究采用巢式方差分析、主成分分析、聚类分析等方法,对茶条槭主要分布区内7个种群种子和果实的12个表型性状进行比较研究,分析茶条槭种群间和种群内的表型多样性以及与地理生态因子的关系。 结果表明:除种子长/宽(SLW)外,其它11个表型性状在茶条槭种群间和种群内均具有显著差异; 各性状平均变异系数(CV)为13.90%,变异幅度为8.14%～32.08%; 种群间翅果性状的平均变异系数(15.63%)高于种子性状的平均变异系数(8.71%),表明种子性状的稳定性高于果实性状。主成份分析中,果实形态特征对茶条槭种群表型的贡献率大于种子贡献率。种群间表型分化系数为35.47%,说明种群内变异(64.53%)大于种群间变异(35.47%),暗示变异主要来源于种群内变异。茶条槭种子和果实表型性状受地理生态因子影响较小,主要受自身遗传因素的影响。基于种群间欧式距离的聚类分析将茶条槭7个种群分为2大支,没有严格按照地理距离而聚类,表明茶条槭种群表型性状变异的不连续性。茶条槭不同种群种子和果实具有较高的表型多样性,与其分布范围和生物学特性有关。

Abstract:

Nested variation, coefficient of variation, principal component analysis and UPGMA cluster analysis were used to analyze phenotypic traits of seeds and fruits among populations for determining the phenotypic traits variations of Acer ginnala populations and its relationship with geographical ecological factors. We made a comparative study on twelve phenotypic traits of fruits and seeds in seven natural populations of Acer ginnala from seven provinces. The results showed that there were abundant variations in phenotypic traits of fruits and seeds among and within populations of A. ginnala. And there were eleven phenotypic traits except for seed length/seed width(SLW)occurring extremely significant differences among populations and within population. Coefficient of variance(CV)of the twelve phenotypic traits was 8.14%-32.08%, with an average of 13.90%. And the variance coefficient of seeds among populations(8.17%)was lower than that of wing fruits(15.63%), which indicated that the seeds had higher stability than the fruits. Principal component analysis(PCA)showed that the contribution of morphological characteristics of fruits to the phenotypic traits of A. ginnala populations was higher than that of seeds, which indicated that the main variation source of A. ginnala came from the fruits. Mean coefficient of phenotypic differentiation between populations was 35.47%, which was lower than that within populations(64.53%), indicating that the variance within population was the main source of the phenotypic variation for A. ginnala. Twelve phenotypic of seed and fruit traits of A. ginnala were less affected by the geographical ecological factors, which were mainly affected by their own genetic factors. All seven studied populations could be clustered into two groups by UPGMA, but were not strictly classified according to the geography distance, indicating the discontinuity in the variation of twelve phenotypic traits. A. ginnala possessed a high level of phenotypic diversity, which might result from its biological characteristics and large geographical distribution ranges. The multiple variations among and within populations would provide insights and guidelines for the genetic conservation and utilization of A. ginnala resources. At the same time, it is of great significance for further study of genetic diversity, conservation of germplasm resources, rational development of natural forests and cultivation of plantations.