Leaf morphology and genetic diversity of Aquilaria sinensis in Dongguan and its surrounding areas

The population genetic diversity and differentiation of Aquilaria sinensis were analyzed by using ISSR. A total of 105 loci were generated by using 9 primers for 221 samples of 4 A. sinensis population. A toal of 104 loci were polymorphic and the percentage of polymorphic bands (PPB%) was 99.05%. Observed number of alleles (Na) and effective number of alleles (Ne) were 1.9905 and 1.5854 respectively. Effective number of alleles (H) and Shannon爷s information index (I) were 0.3390 and 0.5054 respectively. These results indicated that there was a high level of genetic diversity in A . sinensis at the species level. Total gene diversity (Ht) was 0.3236 among 4 populations of A. sinensis. Gene diversity within population (Hs) is 0.2500. The Nei爷s coefficient differentiations (Gst) was 0.2274. The estimate of gene flow (Nm) was 1.6983. The results of UPGMA revealed that the samples of Dianbai population clustered with Dalingshan population firstly, then clustered with Qingxi population. The samples of Guangxi population didn爷t cluster with the other populations which showed that it had large genetic divergence form them. The results of UPGMA of individual samples revealed that between the first and second generations of Dianbai population, there was larger divergence in the large-leaved subgroup than that of small -leaved one. The small -leaved subgroup of Dalingshan population had close relation with the first generation subgroup of Dianbai one. The large-leaved subgroup of Dalingshan population had close relation with the Qingxi population. These results revealed that part of Dalingshan population might come from Qingxi population, and the rest of Dalingshan population might have the same origins with Dianbai population.