红豆树优树子代遗传多样性及与生长相关性分析

目的]研究红豆树优树自由授粉子代遗传多样性及其对生长的影响,比较天然居群子代和孤立木子代遗传多样性差异,揭示子代遗传多样性的变化规律及天然居群在子代遗传多样性维持中的作用,为红豆树遗传保育和优异种质挖掘提供科学依据。方法]以来自浙、闽、赣、川等26个红豆树优树自由授粉家系为研究对象,利用11对SSR引物对765个子代群体进行遗传多样性评价,同时分析子代遗传多样性参数与种子、生长性状的相关性。结果](1)红豆树优树子代群体具有较高的遗传多样性,有效等位基因数为7.766个,观测杂合度(H_O)和期望杂合度(H_E)分别为0.469和0.865。(2)除SSR8外,其余位点的观测杂合度均小于期望杂合度,表明子代群体绝大多数位点处于杂合子缺失状态。(3)红豆树不同家系的遗传多样性存在明显差异,12号家系的遗传多样性水平最高,8号家系则最低。(4)比较发现,天然居群子代的遗传多样性显著或极显著地高于孤立木子代。(5)F统计量和分子方差分析(AMOVA)均表明,红豆树优树子代群体的遗传变异主要存在于家系内,家系间的遗传分化相对较小。(6)相关性分析发现,子代遗传多样性参数与种子性状、子代年高生长量呈显著正相关(r=0.378~0.527)。结论]较大的红豆树天然居群在维持其子代较高遗传多样性中发挥了重要作用,子代遗传多样性显著影响苗木生长,这为红豆树遗传保育和优良家系选择提供了理论依据。

Analysis of Genetic Diversity Among Progenies from Plus Trees of Ormosia hosiei and Its Correlation with Growth

Objective] To assess the genetic diversity of open-pollinated progenies of Ormosia hosiei and its effect on the growth, and compare the genetic differences of progenies derived from populations and isolate trees, to reveal the change of progenies of O. hosiei plus tree and the role of natural populations in maintenance of genetic diversity, so as to provide references for the genetic conservation and excavation of excellent germplasm resources.Method] Eleven polymorphic SSR loci were used to evaluated the genetic diversity of 765 progenies of 26 plus trees coming from Zhejiang, Fujian, Jiangxi and Sichuan provinces and the correlation of genetic diversity parameters with seed and growth traits, meanwhile, the correlation of genetic diversity parameters with seed and growth traits was analyzed.Result] (1) The genetic diversity of offspring was rich with the number of 7.766 of effective alleles, the values of observed heterozygosity (H_O) and expected heterozygosity (H_E) were 0.469 and 0.865 respectively. (2) The H_O among loci were less than the H_E except SSR8, indicating that the majority locus of offspring was in heterozygous deletion state. (3) The genetic diversity of different families was also different significantly, with the highest appeared in the family 12, and the lowest in the family 8. (4) The genetic diversity of population progeny was significantly higher than that of the isolates. (5) The genetic variation of offspring population mainly existed within family rather than among the families based on the F statistic and analysis of molecular variance (AMOVA). (6) The genetic diversity of offspring was positively correlated with the seed traits and annual increment of seedling height (r=0.378-0.527).Conclusion] Higher genetic diversity in the offspring of natural populations of O. hosiei plus tree that played an important role in the maintenance of genetic diversity could significantly promote the growth of seedling. These findings could provide references for the selection of superior family.