ISSR analysis reveals high intraspecific variation in Rauvolfia serpentina L. – A high value medicinal plant

Rauvolfia serpentina L. is a high value medicinal plant having wide distribution in the tropics as well as other parts of the world. Thirteen accessions of Rauvolfia collected from different locations in the Western Ghat region of the peninsular India were analyzed for genetic variation using 15 ISSR primers. The 91 polymorphic amplicons generated were statistically analyzed using WinDist and PopGene software to calculate various diversity indices. Contrary to the general concept of low genetic variation associated with inbreeders, R. serpentina exhibits high genetic diversity as the similarity index value based on Nei and Li’s similarity coefficient ranges from 0.44 to 0.92 with mean value of 0.70. This is supported by other diversity parameters like Degree of genetic differentiation (Gst), Gene flow (Nm), Nei’s gene diversity (h) and Shannon index of genetic diversity (I). Cluster analysis showed characteristic grouping which is not in accordance with their geographical affiliation. The result indicates that ISSR markers are sufficiently informative in assessing genetic diversity across wild accessions of R. serpentina. The high genetic diversity observed in this otherwise self-pollinated plant entails the need for evolving effective ex-situ strategy for long-term conservation of this medicinal herb.

► Though widely distributed, Rauvolfia serpentina is in IUCN red list.
► The plant shows high genetic diversity despite being an inbreeder.
► Cluster analysis did not reflect geographical affiliation of the accessions.
► The high genetic diversity may be due to its broad genetic base.
► Ex-situ conservation and homestead cultivation recommended for conservation.