中国板栗9个结果母枝相关表型性状遗传多样性研究

Genetic Diversity Analysis of Several Phenotypic Traits Related to Biennial Bearing Branch in Chinese Chestnut

以中国10个省份(群体)的164份板栗种质为材料(种植在立地条件相同的同一地块,连续3年采用相同的修剪技术和标准修剪),对母枝结果枝数、雄花枝数、纤弱枝数、结果枝长度、果前梢长度、结果枝节间长度、结果枝粗度、结果枝节位数和结果枝结苞数等9个表型性状量化赋值后进行系统分组设计、方差分析和聚类分析。结果显示:结果母枝的9个表型性状值在群体间和群体内差异均达极显著水平,说明这些性状在群体间和群体内均存在丰富变异;9个表型性状平均变异系数为19.4%～64.0%,其中母枝上雄花枝数、纤弱枝数和果枝结苞数的变异系数> 40%,说明这3个性状改良潜力较大;9个表型性状在群体间表型分化系数为65.9%,群体内为34.1%,说明这些表型性状的变异主要来源于群体间;通过系统聚类,依据表型差异可将10个群体划分为4大类群,基本按地理距离而聚类。

For further enriching genetic diversity information of phenotypic traits on Chinese chestnut germplasm resources,9 phenotypic traits related to biennial bearing branch of 164 Chinese chestnut germplasms from 10 provinces(as 10 populations)were designed with hierarchical classification and then were done with analysis of variance and systematic cluster analysis. The results showed that differences among and within populations of 9 phenotypic traits value were highly significant,indicating a wide range of variation existed in these two levels. The average variation coefficient of the 9 phenotypic traits was 19.4%–64.0%,especially,variation coefficient concerning 3 of the 9 traits including the average male flower shoot number/biennial bearing branch,the delicate shoot number/biennial bearing branch and the average bur number/branch,reached > 40%,which suggested that the germplams had a great potential of genetic breeding in the 3 phenotypic traits. The average of phenotypic differentiation coefficient among populations and within populations were 65.9% and 34.1%,respectively,illustrating that the variationamong populations was the leading source of trait variation. The systematic cluster analysis showed that 10 populations can be divided into 4 groups based on the variation of phenotypic traits,which indicated that the phenotypic traits of Chinese chestnut populations were basically clustered according to geographical distance.