Assessment of population genetic diversity of Derris elliptica (Fabaceae) in China using microsatellite markers

• Derris elliptica is an important source of the insecticide rotenone.
• The genetic variation of 14 populations in China was examined using 25 SSR markers.
• D. elliptica has a high level of variation and inter-population differentiation.
• Multiple sources of introduction and vegetative reproduction mode play main roles.

Derris elliptica (Fabaceae) is one of the most important sources of the insecticide rotenone. This plant was first introduced from different Southeast Asian countries to China in the early decades of last century. The purpose of this study is to assess genetic diversity of D. elliptica in China for the conservation of its germplasm resources and for future breeding programs. Genetic diversity and population structure of 14 cultivated populations of D. elliptica in China were detected using 25 microsatellite markers. A moderate level of genetic diversity was found across the whole sample (expected heterozygosity, He = 0.529), indicating a history of multiple sources of introduction and a broad genetic base for the crop cultivated by cuttings. The genetic diversity at the population level (Mean He = 0.31) was relatively lower. Repeated bottlenecks or founder effects in its short cultivated history and also its vegetative reproduction mode may explain the results. FST (Wright F-statistic) values and AMOVA (analysis of the molecular variance) indicated large genetic differentiation among populations (FST = 0.461; 44.1%, AMOVA), while the cluster analysis showed that the collections belong to two major groups of genotypes. The initial difference in the introduced germplasm from the primary center of origin and the limited gene flows among populations may have played important roles in shaping the genetic variation pattern in D. elliptica of China.