[Patch diversity and spatial structure of wild Thymus quinquecostatus]

With the combination of ISSR (inter-simple sequence repeats), SRAP (sequence-related amplified polymorphism) and spatial autocorrelation, the genetic diversity and spatial structure per unit patch of three Huaiyuan populations of Thymus quinquecostatus in southeast China were analyzed. The results showed that there existed higher levels of genetic and clonal diversity among the patches within the wild T. quinquecostatus populations, with the percentage of polymorphic loc being 75.75%, Nei's gene diversity being 0.2537, Shannon's information index being 0.3811, percent of genetype (G/N) being 0.61, Simpson index (D) being 0.96, and Fager index (E) being 0.91. Analysis of molecular variance (AMOVA) showed that only 9.65% of genetic variation resided among the populations, while 90.35% of it resided among the individuals within the populations. No genotype patches in common were observed among the three populations. The spatial distribution of the same patches showed a concentrated distribution about 0-25 m, and that of different patches showed an inlaid distribution. Except for some locations that showed par correlations in the Huaiyuan populations of T. quinquecostatus, most locations lacked in spatial structure according to spatial autocorrelation analysis. The possible mechanism causing the establishment of the patches of T. quinquecostatus populations was due to seed dispersing, and the following clonal reproduction played important roles in patch development and population expanding.