我国肉苁蓉寄主梭梭种质资源多样性的AFLP分析

该研究主要采用AFLP技术结合PopGene32和NTSYSpc2.1软件分析了我国西北地区5省14地103份梭梭的遗传多样性。结果表明：梭梭群体总的多态位点百分率为94.13%，5个省居群平均Nei’s基因多样性指数（H）为0.308 0，Shannon’s多态性信息指数（I）为0.467 6，说明梭梭种群内遗传多样性较高。基因分化系数（G_st）为0.313 8，即68.62%的遗传变异来自省内，31.38%的遗传变异来自省间。5个省间的基因流（N_m）为1.093 5，其基因流属于风媒异交植物的特征。AMOVA分析表明，梭梭89.34%的遗传变异出现在省内，仅有10.66%的遗传变异发生在省与省之间，进一步分析得知省内的遗传变异主要发生在各采样点居群间（84.80%）。依据Nei’s遗传距离对不同居群进行UPGMA聚类分析，得知新疆和青海的梭梭样品和其他各省相比其遗传关系较远且各自聚为一支，而甘肃、内蒙古和宁夏产区的样品遗传关系较近聚为一支。总之，我国梭梭种群遗传多样性较高，各地区之间的遗传分化较小，现阶段该物种的种内丰度较高。因此，加强不同地区的梭梭种质繁育和人工种植推广可以有效的保护野生梭梭资源并实现可持续利用。

AFLP analysis on genetic diversity of Haloxylon ammodendron in China

To determine the genetic diversity of Haloxylon ammodendron collected from 14 sites in 5 provinces,103 H. ammodendron samples of 12 wild populations and 2 cultivated which collected from 14 sites in 5 provinces were analyzed by amplified fragment length polymorphism (AFLP) DNA markers. PopGen32 and NTSYSpc2.1 was applied to evaluate genetic diversity of H. ammodendron populations. The average percentage of polymorphic loci (PPL) of total H. ammodendron populations was 94.13%, the average Nei's gene diversity index (H_e) from 14 populations was 0.308 0, and the Shannon's genetic diversity index (I) was 0.467 6. The results indicated that the genetic diversity of H. ammodendron populations was high. Genetic differentiation index (G_st) was 0.313 8, and the gene flow (N_m) was 1.093 5 at the population level. The level of gene flow of H. ammodendron showed it possessed the feature of wind-pollinated outcrossing plants. AMOVA analysis indicated that genetic variation of H. ammodendron was much higher within groups (89.34%) than that among groups (10.66%), moreover genetic variation within groups mainly occurred among populations in different producing areas (84.80%). Cluster analysis (UPGMA) was applied to generate dendrogram based on Nei's genetic distances of 14 populations. Samples from Xinjiang and Qinghai were clustered respectively as a clade for their distant genetic relationship, while Samples from Gansu, Inner Mongolia and Ningxia were clustered together for their close genetic relationship. Genetic diversity of H. ammodendron populations is high in China, and genetic differentiation among regions is small, thus abundance within this specie is high at this stage. Therefore, wild nursery and artificial cultivating in different areas are effective measures for the conservation and sustainable utilization of H. ammodendron resources.