广西马尾松三个优良种源的遗传多样性及生长性状变异分析

【目的】以25年生马尾松种源、地点、林分3水平子代试验林为研究材料,从表型、遗传变异两方面开展研究,以期为马尾松遗传育种策略的制定提供有价值参考。【方法】采用SSR分子标记进行遗传结构分析,使用Arlequin 3.5软件依据线性模型估算各层次变异的相对分量。以SAS分析软件依据线性模型对林分生长量数据进行统计分析,以4因素嵌套模型估算各层次变异的相对分量。【结果】遗传多样性分析结果表明,种源间及种源内无明显的遗传分化。分子方差分析结果表明,种源间的遗传变异仅占总变异的2.56%,种源内不同地点间的变异占1.66%,地点内个体间的遗传变异则占总变异的95.78%。生长表型数据分析结果同样显示胸径与材积性状在种源间、种源内地点间、同一地点的优良林分与普通林分间均无显著差异。【结论】分子方差分析与生长性状表型数据方差分析的结果均表明,广西马尾松的主要遗传变异存在于林分内个体间。因此在优良种源中开展优良单株选择可以获得更好的改良效果。该结论对于马尾松遗传育种策略的制定具有重要的参考价值。

Analysis of genetic diversity and variation of growth traits of three superior provenances of Pinus massoniana (masson pine) in Guangxi

【Objective】This paper describes the study of a test plantation of 25-year-old Pinus massoniana (masson pine) trees, in which gene expression and DNA variation were examined on three levels: provenance, location and stand. The purpose was to provide a valuable reference from which genetic breeding strategies can be developed.【Method】The SSR molecular marker was used to perform genetic structure analysis, and the Arlequin 3.5 software was used to estimate the relative weight of each level of variation according to the linear model. The stand growth data were analyzed statistically by the SAS analysis software based on a linear model, and the relative weight of each level of variation was estimated by the four-factor nested model.【Result】Genetic diversity analysis showed that there was no obvious difference between provenances or within the same provenance. The results of molecular ANOVA analysis showed that the genetic variation between provenances accounted for only 2.56% of the total variation, and different locations within a provenance accounted for 1.66%. Alternatively, differences between individuals among those locations tested accounted for 95.78% of the total variation. Analysis of the growth phenotype data also showed no significant difference in diameter at breast height (DBH) and volume character between provenances, between locations within a provenance, or between superior and normal stands within a location. 【Conclusion】ANOVA analyses of molecular and growth phenotype data revealed that the major genetic variation of masson pine in Guangxi exists among individuals within a stand. Therefore, it is better to develop superior individual plant selection criteria in a superior provenance. This conclusion provides valuable information that can be used in the formulation of genetic breeding strategies for masson pine.