Phenotypic variation of the mangrove species Avicennia marina (Forssk.) Vierh. from seven provenances around Australia

Avicennia marina is the most widely distributed of all mangrove species. This study examined phenotypic characteristics of seedlings raised from seven provenances of the species widely spread around the Australian coast from tropical to temperate regions. Seedlings were grown together for 18 months in a glasshouse at Lismore in sub-tropical eastern Australia. The provenances displayed differences in propagule and seedling size and seedling leaf characteristics that could be related to geographic occurrence but showed no distinct geographical cline. Consistent with other phenotypic and genetic studies of A. marina, phenotypic variation was mainly between provenances and between individuals across the entire population, rather than between individuals within any one provenance. The results suggested that provenance populations may have developed individually, separated by geographical barriers. If it can be assumed that characteristics observed in the present trial are likely to expressed by provenances when grown away from their natural environment, the present work has identified provenances that might be explored to find desirable individuals with phenotypes that might have value in mangrove planting or breeding programmes.