Allozyme variation of the endangered endemic plant Myricaria laxiflora Implications for conservation

Myricaria laxiflora a riparian plant that naturally occurs in the riverbanks of the Yangtze River Valley has become extinct across its entire geographical distribution range in the wild due to the construction of the Three Gorges Dam The allozyme variation of M lax(flora populations was investigated in the present study Mean number of alleles per locus (A) was 2 35 and the observed heterozygosity (H-o) and expected heterozygosity (H-e) were 0 35 and 0 30 respectively Six populations showed significant excesses of heterozygotes based on the examination of a multilocus fixation index (F-IS) The population genetic divergence of M laxiflora is high (G(ST) = 0 144 and theta(B) = 0 131) and the analysis of molecular variance analysis shows that 19 71% of the total genetic variation is caused by the difference between populations Based on the obtained genetic information six management units have been identified all of which are expected to enhance the effective management of the remaining and transplanted individuals of this endangered species in the future (C) 2010 Elsevier Ltd All rights reserved