基于AFLP分子标记的不同类型野生桂花种群遗传结构分析

桂花Osmanthus fragrans具有极高的经济价值和观赏价值。研究野生桂花种群的遗传多样性有利于为新品种的选育以及野生桂花资源的保护提供重要的依据。利用扩增片段长度多态性(AFLP)技术对江西全南(衰退型)和福建长汀(稳定型)这2个桂花自然种群96个个体进行了遗传多样性评估。7对引物组合共检测到330个清晰位点,其中多态位点276个,占83.64%。在物种水平,桂花的Shannon多态性信息指数(I)为0.428 3,Nei’s基因多样性(He)为0.285 6,表明桂花具有丰富的遗传多样性;在种群水平,福建长汀种群的多态性指数均高于江西全南种群,表明包含不同世代、具有较好自然更新能力的长汀种群携带更丰富的遗传信息;分子方差分析(AMOVA)表明:桂花的遗传变异主要存在于种群内(71%),种群间的遗传变异只占29%;2个种群间存在一定的遗传分化(Gst=0.161 6),种群间基因流较小(Nm=2.594 9)。

Genetic structure of different natural Osmanthus fragrans populations based on AFLP method

Osmanthus fragrans is being concerned in recent years due to its high economic value and ornamental value. It can provide significant evidences for breeding of new cultivars and protecting of natural populations with studying on the genetic diversity of natural populations of O. fragrans. The genetic diversity of 96 O. fragrans individuals of two natural populations from Quannan County of Jiangxi Province and Changting County of Fujian Province was estimated using amplified fragment length polymorphism （AFLP） method. A total number of 330 reproducible bands were amplified using seven AFLP primer combinations, and 276 bands were polymorphic with a proportion of 83.64%. At the species level, Shannon’s information index （I） was 0.428 3, the Nei’s genetic diversity （H_e） was 0.285 6, which indicated the genetic diversity of O. fragrans was rich; at the population level, Shannon’s information index and Nei’s genetic diversity of Fujian population was higher 1.5 than Jiangxi population, that showed Fujian population owned much rich genetic resource. Moreover, AMOVA indicated the most total genetic variation was within populations with a proportion of 71% and the less was among the populations with a proportion of 29%. Meanwhile, a certain extent level of genetic differentiation （G_st=0.161 6） was detected among the populations and genetic flow was 2.594 9.  ［Ch, 2 fig. 4 tab. 23 ref.］