Genetic Analysis of Tropical Orchid Hybrids (Dendrobium) with Fluorescence Amplified Fragment-length Polymorphism (AFLP)

Abstract

Intensive breeding activities of tropical orchids have given rise to many hybrids, among which genetic relationships are difficult to evaluate due to free interbreeding of different species in the same genus or even from different genera, the use of hybrids for further breeding, use of abbreviated or trade names and sometimes intentional non-disclosure of parentage for commercial considerations. We have subjected 43 popular commercial Dendrobium hybrids to fluorescence amplified length polymorphism (AFLP) analysis and their genetic relationship was estimated. The hybrids bearing flowers of similar shapes and colors were clustered into five groups. Each hybrid tested had a distinct AFLP fingerprint profile except the tissue culture mutants. Sibling hybrids were closely clustered (with genetic distance <0.09) followed by those sharing one parent. These results suggest that AFLP fingerprint profiling gives accurate and objective estimation of genetic relationship of the Dendrobium hybrids tested. Our study also found that the AFLP fingerprint profiles were uniform in different parts of tested plants, stable among individuals in vegetatively propagated populations throughout different growth periods. We conclude that AFLP fingerprint profiling has the potential to be an integral part of current new plant varieties protection sytems.