[Genetic diversity and genetic structure evaluation of cultivated Chinese wolfberry (Lycium barbarum) based on microsatellite population genetics].

A total of 178 Chinese wolfberry individuals from 17 populations were detected by 7 pairs of SSR primers to evaluate genetic diversity and structure, using software GenALEx 6.5,NTSYS,STRUCTURE, the effects of cultivation on genetic diversity and structure were clarified aiming to find the strategies for genetic management and sustainable use. The results showed that the genetic diversity of cultivated Chinese wolfberry was low. The average number of alleles N_A, expected heterozygosity H_E, observed heterozygosity H_O, and Shannon's information index H' was 3.9, 0.443 7, 0.556 6, 0.788 1, respectively. STRUCTURE, UPGMA clustering and PCA test indicated that Chinese wolfberry varieties were severely intermixed but no differentiation among varieties. Mantel test showed no significant correlation between genetic distance and geographic distance. AMOVA analysis showed that genetic variation mainly occurred among individuals within the population(84.58%, P<0.001), and there was almost no genetic differentiation between varieties(3.63%, P<0.001) and between populations(11.79%, P<0.001). The cultivation has caused a significant decline in the genetic diversity of Chinese wolfberry, which may cause inbreeding decline. New germplasm resources should be sought from the wild to improve the existing cultivars. On the other hand, there are obvious homogenization and germplasm intermixing between cultivated varieties and populations. Meanwhile, Chinese wolfberry cultivars should be purified and prevented from flowing into the wild population, in case of causing pollution of the wild germplasm.