Abstract:

Siraitia grosvenorii, a liana species of the Cucurbitaceae endemic to southern China, is an important economic plant. The genetic diversity of 130 individuals from seven Siraitia grosvenorii populations from Guangxi and Guangdong provinces was estimated using inter-simple sequence repeat (ISSR) markers. The fifteen primers employed produced a total of 111 scorable amplified fragments, of which 91 (82.0%) are polymorphic. Genetic diversity analysis showed that Nei′s gene diversity (H_e) was 0.248 and Shannon′s genetic diversity index (I) was 0.354. Genetic differentiation mainly occurred among populations (G_st=0.569). The correlation between genetic distance and geographic distance among the populations was not significant （r = 0.369, P=0.115）. UPGMA cluster analysis showed that the 130 individuals were clustered into seven clusters corresponding to the seven populations.

Key words: coadaptation, outbreeding depression, genetic assimilation, heterosis, introgression