Analysis of natural intraspecific variation in rhododendron nilagiricum Zenk of Nilgiris using RAPD

摘要

Rhododendron nilagiricum Zenk is the only paleoendemic species of Rhododendron found at Nilgiris. Random amplified polymorphic DNA (RAPD) analysis was carried out to study the extent of genetic polymorphism in trees collected from five locations at Nilgiris. Of the 15 primers tested, 10 revealed polymorphism. The percentage polymorphism ranged from 40 to 92 with an average of 61.5 polymorphism per primer. Pair wise comparisons were made for the RAPD profiles obtained through the use of 10 primers in the representative samples. Data analysis was done by using the POPGENE statistical package. The similarity matrix and the dendrogram obtained showed that there was close similarity between trees collected from different regions of Nilgiris. The cluster analysis showed positive correspondence between genetic diversity and geographic distance. primer OPZ 13 generated the highest number of bands among the primers, revealed maximum polymorphism and had the greatest capacity for discriminating individuals of R. nilagiricum collected from different regions of Nilgiris.