江南油杉(Keteleeria fortunei)种实性状变异及其与环境因子的关系

Ariation in traits of cone and seed of Keteleeria fortunei var. cyclolepis and its relationship with environmental factors

关键词:  遗传变异， 相关性， 江南油杉， 种实， 表型性状， 地理环境因子

Key words:  genetic variation, correlation, Keteleeria fortunei var. cyclolepis, cone and seed, phenotypic traits, geographical environmental factor

摘要:

该研究以广西低海拔盆地向云贵高原过渡的连续地理区域内江南油杉(Keteleeria fortunei var. cyclolepis)林为对象，采用方差分析、多重比较、相关分析、逐步回归分析等方法，对4省（区）9个江南油杉天然种群的16个种实表型性状进行比较研究，探讨种群间种实表型性状多样性及其与地理环境因子的关系。结果表明：江南油杉种实表型性状在种群间存在丰富变异，16个种实性状在种群间均达到显著或极显著差异；9个种群中望谟种群变异最大（2.54%），16个种实表型性状中种子宽变异最大（9.04%），种群间种子性状的变异高于球果的变异，说明球果性状变异稳定性高；种实部分表型性状间呈显著或极显著相关，其中种子宽、种子厚、种子长宽比、种鳞长宽比、苞鳞长宽比是较为关键的性状，能在一定程度上反映种实质量；种子性状受地理环境因子的影响比球果大，表现为西部种源种子更趋于圆形，饱满，种翅较长，较宽；地理环境因子中，海拔与多数种实性状间呈显著相关性，是种实表型性状变异的主要来源，因此，海拔是影响种实表型性状变异的主要因素。该研究结果对进一步保护、利用江南油杉种质资源具有一定的指导意义。

Abstract:

This study focused on the research of Keteleeria fortunei var. cyclolepis in transitional regions from low lying basin of Guangxi to the Yunnan Guizhou plateau. The purpose was to discuss the diversity in phenotypic traits of cone and seed among populations of K. fortunei var. cyclolepis and its relationship with geographical environmental factors. We made a comparative study on sixteen phenotypic traits of cone and seed in nine natural populations of K. fortunei var. cyclolepis from four provinces. To analyze the experiment data, the main mathematical statistical methods were used including variance analysis, multiple comparison, correlation analysis, and stepwise regression analysis. The results showed that there were abundant variations in phenotypic traits of cone and seed among populations of K. fortunei var. cyclolepis. And there were significant or extremely significant differences in sixteen phenotypic traits of cone and seed among populations. The variation coefficient of natural population in Wangmo was the highest (2.54%) among nine natural populations. The variation coefficient of seed width was the highest (9.04%) among sixteen phenotypic traits. The variation of seed traits was higher than that of cone among populations. It meant that the cone has higher stability. There were significant or extremely significant correlations among part of phenotypic traits of cone and seed. The following phenotypic traits including seed width, seed thickness, seed aspect ratio, seed scale aspect ratio and bract aspect ratio were more important traits. To some extent, they could reflect the quality of cone and seed. Seed traits were more largely influenced by geographical environmental factors compared to cone traits. The seeds in west area were near oval and more satiate. And the seed wings were longer and wider of the seeds in the west than the seeds in other areas. There were significant correlations between elevation and majority traits of cone and seed. Analyzing the outcomes of these experiments, we can draw the conclusion that elevation as a major variation source is the main factor affecting variation in phenotypic traits of cone and seed of K. fortunei var. cyclolepis among geographical environmental factors. These results offer information in protecting and taking advantage of germplasm resources of K. fortunei var. cyclolepis.