ISSR variation in the endemic and endangered plant Cycas guizhouensis (Cycadaceae)

Background and Aims Cycas guizhouensis (Cycadaceae) is a rare and endangered species endemic to the southwest of China. An investigation was undertaken into the genetic variation of wild populations. Methods ISSR markers were used to determine the genetic variation within and between 12 extant populations of this species. Key Results Low genetic diversity (at population level, P = 14.21 %, HE = 0.0597; at species level, P 35.90 %, H, = 0.1082) and a high degree of differentiation among populations (G(ST) = 0.4321) were detected. Conclusions This genetic structure is considered to be due to the combined effects of slow biochemical evolution, genetic drift, inbreeding and limited gene flow between populations. Based on these findings, strategies are proposed for the genetic conservation and management of the species. (C) 2004 Annals of Botany Company.