Allozyme Diversity and Population Structure of Caragana korshinskyi Kom.in China

Caragana korshinskyi Kom. is a long-lived shrub species indigenous to northwestern China, and important in vegetation rehabilitation of widely degraded and degrading semiarid and arid regions because of its high ecological and economic values. Information at molecular level on its genetic diversity, however, is not available. Accordingly, the extent and distribution for genetic diversity and population structure in 11 populations of C. korshinskyi were assessed using polyacrylamide gel electrophoresis for seven enzymes including aminopeptidase, aspartate aminotransferase, glucose-6-phosphate dehydrogenase, malate dehydrogenase, phosphoglucoisomerase, phosphogluconate dehydrogenase, and peroxidase. The seven-enzyme systems produced 11 loci encompassing 19 alleles demonstrating high genetic variation at both species and population levels. A considerable excess of heterozygotes relative to Hardy–Weinberg expectations was detected at the both levels as well. G_ST ranged from 0.0074 for AMP-1 to 0.4646 for PGD with a mean of 0.1517, indicating that approximately 84.8% of the total allozyme variation occurred within populations. An indirect estimate of the number of migrants per generation indicated that gene flow was high among populations of the species.