Eco-geographic survey of wild species of Vigna in Sri Lanka

Abstract

The ceo-geographic survey of plant genetic resources is essential for effective in situ and ex situconservation of plant genetic resources. Results of eco-geographic survey could be used to predictnew areas for survey and to assist in the formulation of collection and conservation priorities. An ecogeographicsurvey was conducted in Sri Lanka during August 2005 to February 2006 in some protectedareas and other target areas of Sri Lanka to locate wild species of Vigna, map their localities, identifythreatened areas and find out suitable locations for in-situ conservation.

Habitats and taxonomic characteristics data were recorded. Locations of wild spices of Vigna werenoted by using Global Positioning System (GPS). The distribution of six wild species of Vigna occurringin Sri Lanka is depicted in the maps. GPS data were analyzed by Flora map distribution modelling andprobable localities of Vigna wild species were mapped. Six species of Vigna recorded by the surveyare distributed from 0 MSL to 1630 m MSL. However, V stipulacea, V trilobata and V aridicolawere found only lower latitudes (0 to 130 m MSL) and V dalzilliana and V trinervia are limited tohigher elevation (790m to 1630m MSL). Vigna radiata var. sublobata was found only in one locationDambana in Badulla district. V stipulacea, and V trilobata are mostly found near sea shore and Varidicola is found in inland dry areas. Difference in leaf shape of V trilobata is observed in differentpopulations. The probable areas that were identified using flora map modelling are located in Puttalam,Polonnaruwa, Ampara, Kurunagala and Batticola districts. Surveys in these areas are needed toidentify new populations ofwild Vigna species.