Variation in inter-simple sequence repeat (ISSR) in mangrove and non-mangrove populations of Heritiera littoralis (Sterculiaceae) from China and Australia

Genetic diversity within and among 10 mangrove and non-mangrove populations of Heritiera littoralis from three sites in China and one site in Australia was determined using inter-simple sequence repeats (ISSR). Eleven primers produced 173 hands across a total of 166 individuals. At the species level, genetic diversity was high (P = 93.1%, He = 0.24, and I = 0.37). Higher genetic diversity was observed in Australian populations compared to Chinese populations, which can be explained by either ecogeographic variation or evolutionary history. A significant correlation between genetic and geographic distances was detected among the 10 populations, but no Such correlation was found among either Chinese or Australian populations. AMOVA indicated that 41.7% of the total genetic variation was explained by differences between China and Australia. As for Chinese populations, 22.5% of the genetic variation Was accounted for by geographical effects with 5.3% for differentiation between habitats. We Suggest that geographic distance is the primary cause of genetic differentiation between China and Australia at the regional scale, whereas, the strongly divergent habitats (marine versus terrestrial) also play an important role in within region differentiation at the local scale. An understanding of the genetic Structure of H. littoralis provides insight for the conservation and the management of these species. (C) 2004 Published by Elsevier B.V.