Genetic Differentiation in Isolated Populations of Hakea carinata (Proteaceae)

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.