凤丹栽培群体的表型变异研究

从我国6个凤丹(Paeonia ostii T.Hong et J.X.Zhang)中心产区,选取15个群体共398个单株,对20个表型性状进行调查和分析。结果显示,枝条数、地径、株高、茎长、冠幅长、冠幅宽、成花枝、芽位数、叶长和叶宽等10个表型性状受植株株龄的影响显著,随着株龄增加,除叶长和叶宽的平均值呈递减趋势外,其他8个性状的平均值都呈现递增趋势。凤丹群体间的表型分化系数为0~50.14%,平均值为27.62%,变化幅度最大的是二年生枝长,最小的为心皮数和二年生枝径。对当年生枝长、芽位高、当年生枝径、顶生小叶长、二年生枝径、顶生小叶宽、复叶数、心皮数、二年生枝长和叶柄长等不受株龄影响的10个表型性状进行主成分分析,结果显示前6个性状是影响表型差异的主要性状。各表型性状间存在一定的相关性,聚类分析结果将受株龄影响的10个性状划分为4组。研究结果表明凤丹表型性状在群体间和群体内的变异非常丰富,可为遗传改良和品种选育储备丰富的植物材料。

Phenotypic variation in cultivar populations of Paeonia ostii T. Hong et J. X. Zhang

In the present study, variation in 20 phenotypic traits of 398 samples of Paeonia ostii T. Hong et J. X. Zhang from 15 seedling populations in six provinces were investigated and analyzed. Results showed that 10 traits, including branch number, ground diameter, plant height, stem length, crown length, crown width, flower branch, bud number, leaf length, and leaf width, were significantly affected by plant age. With the increase of plant age, the mean values of leaf length and width showed a decreasing trend, whereas the other eight traits showed an increasing trend. The average phenotypic differentiation coefficients (Vst) between populations were between 0 and 50.14%, with an average value of 27.62%. Annual growth length exhibited the largest variation, whereas number of carpels and annual diameter showed the smallest. Principal component analysis was conducted for the 10 traits affected by plant age, including length of one-year-old branches, bud height, diameter of one-year-old branches, length of terminal leaflets, diameter of two-year-old branches, width of terminal leaflets, leaf number, carpel number, length of two-year-old branches, and petiole length. Results showed that the first six characters were the main traits accounting for the phenotypic differences. There were some correlations between phenotypic traits, with the 10 traits affected by plant age being divided into four groups by cluster analysis. There was great variation among populations and within populations in these provinces, which provides a wealth of material for variety breeding and germplasm innovation for P. ostii.