Genetic analysis of rainforest vines has seldom been undertaken. Thus the genetic implications of habitat fragmentation are largely unknown, making guidance for conservation, recovery and translocations of threatened rainforest vines unpredictable. The threatened rainforest vine Marsdenia longiloba (Apocynaceae) has potentially been impacted by development and habitat fragmentation. This Australian species has rarely been observed to reproduce sexually leading to ambiguity in field identification and it was thought populations may be largely clonal. Genetic analysis was undertaken to clarify field identification, examine patterns of genetic variability and related aspects of its breeding system and identify patterns of genetic variation within and between populations of M. longiloba across the range of the species. Genetic variability was examined at fine, medium and broad geographical scales. The combination of DNA barcoding and microsatellite analysis has resolved potential species misidentifications in the field collections. Genetic analysis indicated that M. longiloba is not genetically depauperate and that larger populations contain more genetic diversity than smaller ones. Populations were not primarily composed of clones, although partial clonal structuring was detected especially in the southern part of its distribution. There was evidence of genetic clustering of plants at a medium landscape scale, but little evidence of broad regional genetic differences.
Botanical Journal of the Linnean Society / Vol. 183, No. 1, pp.106-123