Dissertation Research: Comparison of Genetic Variation and Breeding Systems of Clidemia hirta (Melastomataceae) Between Native and Introduced Populations

Louisiana State University, Baton Rouge LA

Investigators

Abstract

0073246 Blackwell Plant species that are rare where they are native often become abundant and widespread where they are introduced. Field experiments and greenhouse studies have been initiated to determine whether the observed differences in the abundance and habitat distribution of the invasive shrub Clidemia hirta (Melastomataceae) in its native area (Costa Rica) and area of introduction (Hawaii) result from environmental or genetic differences. This research will be enhanced by conducting a broad-scale survey of the genetic structure of native and introduced populations of C. hirta to determine whether those in Hawaii are similar or depauperate in genetic variation to those in the native range. This study will determine whether shifts in the breeding system or genetic structure have occurred that would affect the invasiveness of C. hirta. The historical process of the invasion (numbers of introductions, presence of founder effects, adaptation after introduction) and the resulting distribution of different genotypes among the Hawaiian Islands will also be examined. This study is the first comparison of genetic variation and breeding system of a woody plant between its native and introduced areas. Information about the genetic diversity of this species in Hawaii will be valuable for devising effective biological control programs that match locally adapted genotype-natural enemy pairs.