不同产地幼龄秀丽四照花生长和形质性状家系变异分析

Variation of Growth and Form-quality Traits of Cornus hongkongensis Family from Different Seed Sources

[目的]对来自不同产地幼龄秀丽四照花优树家系进行测定,以揭示其生长和形质性状的家系遗传变异规律,为秀丽四照花种质资源利用和遗传改良提供科学依据。[方法]利用2016年设置在浙江龙泉的3年生来自不同产地的秀丽四照花优树家系试验林,分析生长和形质性状在产地间和产地内家系间的遗传变异以及性状间的相关性,基于9个性状对秀丽四照花进行主成分和聚类分析。[结果]秀丽四照花家系各性状在产地间和产地内家系间均呈极显著差异,在9个表型性状中,最大分枝长变异最大(38.78%),树高变异最小(21.53%),生长性状的变异系数为21.53%~26.66%,生长性状的变异系数普遍小于形质性状,各性状在产地内家系间变异(26.61%)大于产地间变异(18.86%)。高径生长量及冠幅较大的秀丽四照花其分枝数较多、分枝较粗,树干分枝数较多、分枝角度较大;冠幅较小的秀丽四照花,其树干通直度较高。9个性状综合成3个主成分,其累计贡献率可达82.636%,树高、最大分枝长和树干通直度分别是生长、形质性状的主要区别性状。92个秀丽四照花家系被聚为2类,类型Ⅰ包括江西广丰、江西上犹、江西龙南、福建大田、福建武平和湖北兴山6个产地内的56个家系;类型Ⅱ包括浙江龙泉、湖南南岳、江西袁州、江西分宜和福建延平5个产地内的36个家系。[结论]秀丽四照花产地间及产地内家系间各性状变异幅度较大,其变异主要存在于产地内家系间。树高、冠幅、最大分枝长和树干通直度等是主要的变异因子。速生家系具有分枝数较多和分枝较粗的特点。参试的秀丽四照花家系被分为2类,类型Ⅰ家系产地在地理位置上大部分偏南部,主要特征为树形高大,株型紧凑,分枝较粗,速生性较好;类型Ⅱ家系产地则大部分偏北部,主要特征为树枝开展,树干通直度较高,速生性较差。

[Objective] Young elite families of Cornus hongkongensis were tested, in order to reveal the genetic variation of the growth and form-quality traits of C. hongkongensis families from different seed sources, and provide a theoretical basis for the exploration and utilization of C. hongkongensis germplasm resources. [Method] 3-year-old C. hongkongensis elite families from different seed sources were used to study the genetic variation of growth and form-quality traits among the seed sources and the families from the same seed source. In addition, the correlation between traits was studied, the principal component analysis and cluster analysis were performed based on 9 traits.The experimental forest was established in 2016 at Longquan of Zhejiang Province. [Result] Significant differences were observed in traits of C. hongkongensis families among the seed sources and the families from the same seed source. Among them, the traits with the largest and smallest coefficient of variation were maxi-branch length(38.78%) and tree height(21.53%), respectively. The variation coefficient of growth traits range was between 21.53%and 26.66%, and the variation coefficient of growth traits was generally lower than that of form-quality traits. The variation of traits within the families from the same seed source(26.61%) was greater than the variation among seed sources(18.86%). The C. hongkongensis family with higher height, larger basal diameter and crown width had more branches and thicker branches. The more branches, the larger the branching angle and the smaller the crown width,the higher the straightness of the trunk. The 9 traits were integrated into 3 principal components, and their cumulative contribution rate could reach 82.636%. Tree height, maxi-branch length and stem straightness were the main distinguishing traits of growth and form-quality traits respectively. The 92 C. hongkongensis families tested were grouped into two categories. Type Ⅰ includes 56 families, which from 6 seed sources, i.e. Guangfeng of Jiangxi, Shangyou of Jiangxi, Longnan of Jiangxi, Datian of Fujian, Wuping of Fujian and Xingshan of Hubei. Type Ⅱ includes 36 families, which from 5 seed sources, i.e. Longquan of Zhejiang, Nanyue of Hu’nan, Yuanzhou of Jiangxi, Fenyi of Jiangxi and Yanping of Fujian. [Conclusion] There are significant variation of the traits of C. hongkongensis among the seed sources and families from same seed sources. Tree height, crown width and maxi-branch length, stem straightness, etc., are the major variation factors. Fast-growing families have the characteristics of more branches and thicker branches. The families tested are divided into two categories. The families included in Type Ⅰ are most from the seed sources in the southern geographically, with the main characteristics of tall form, compact plant-type, thick branches and fast-growing. The families included in Type Ⅱ are most from the seed sources in the northern geographically, with the main characteristics of spreading branches, high straightness of stem and slow-growing.