马尾松不同改良水平子代群体遗传多样性研究

摘要

该研究以马尾松三个不同改良水平的良种生产群体子代为材料,用天然群体作为对照,采用16对SSR引物对试验群体进行遗传多样性分析,并探究遗传改良对马尾松林分遗传多样性的影响.结果表明:马尾松天然群体、母树林子代、1代种子园子代及1.5代种子园子代的Shannon多样性指数 (I) 分别为0.53、0.53、0.53、0.46;观测杂合度 (Ho) 分别为0.36、0.36、0.39、0.35;期望杂合度 (He) 分别为0.32、0.32、0.33、0.27.在这三项主要遗传多样性指标上,马尾松母树林、1代种子园及1.5代种子园的子代之间无显著差异.由此说明,在广西马尾松的遗传改良进程中,遗传多样性并未因改良选择而受到明显的影响.良种人工林与天然林相比较,马尾松良种人工林在三项主要指标上无明显下降,说明广西三类主要的良种群体都具有较好的群体缓冲能力和个体缓冲能力.该研究结果对于科学制定马尾松育种策略具有重要意义,为马尾松高世代育种研究提供了重要的理论依据.%The effects of genetic improvement on the genetic diversity of Pinus massoniana forest were studied, by using three improved levels of progeny of seed production populations as the research material, and the natural population as the control.The genetic diversity of the experimental groups was analyzed by sixteen pairs of SSR primers.The results were as follows: Shannon's information index (I) of natural populations, progeny of seed production area, offspring of Generation 1 seed orchard and Generation 1.5 seed orchard of P.massoniana were 0.53, 0.53, 0.53 and 0.46;observed heterozygosity (Ho) 0.36, 0.36, 0.39, 0.35 respectively;expected heterozygosity (He) 0.32, 0.32, 0.33, 0.27 respectively.There were no significant difference among the offsprings of seed production areas of Generation 1 and Generation 1.5 seed orchards of P.massoniana on the three main genetic diversity indexes.It showed that the genetic diversity of improved varieties was not affected significantly by the improved selection in the process of genetic improvement of P.massoniana in Guangxi.Compared with the plantations and natural forest, we knew that there was no significant decrease in the three main indexes of the improved varieties, which indicated that the three kinds of main populations in Guangxi had good group buffer capacity and individual buffer capacity.The results of the study have important significance for the scientific development of breeding strategy in P.massoniana, and provide important data support for the research of high generation breeding of P.massoniana.