Genetic Differentiation in Isolated Populations of Hakea carinata (Proteaceae)

G. J. Starr and S. M. Carthew

Abstract

Fragmentation of the landscape by human activity has created small, isolated plant populations. Hakea carinata F. Muell. ex Meissner, a sclerophyllous shrub, is common in isolated fragments of vegetation in South Australia. This study investigated whether habitat fragmentation has caused restrictions to gene flow between populations. Gene diversity (H_T = 0.317) is average for similar species but little is held within populations (H_S = 0.168) and 46.9% of gene diversity is accounted for between populations. Estimates of gene flow are N_M = 0.270 (based on F_ST) and N_M = 0.129 (based on private alleles). Populations are substantially selfing (t = 0.111). Small isolated populations appears to be a long-term evolutionary condition in this species rather than a consequence of habitat fragmentation; however, population extinctions are occurring. Conservation will require the reservation of many populations to represent the genetic variation present in the species.

Australian Journal of Botany 46(6) 671 - 682 (1998) doi:10.1071/BT97123