Morphological evaluation of some indigenous cultivars of greater yam (Dioscorea alata L.) of North East India

Abstract

Twenty seven accessions of greater yam (Dioscorea alata L.) were collected throughout North East India. The accessions were being maintained in the Experimental Farm of Department of Horticulture, Assam Agricultural University, Jorhat, under AICRP on Tuber Crops. The accessions were evaluated for different morphological characters during 2020-21 and 2021-22, following International Plant Genetic Resources Institute’s (IPGRI) descriptors for yam. A wide range of variation was observed for morphological characters of both young and mature stem viz. stem colour, absence/presence of wings, wing colour, absence/presence of spines of young stem, colour and absence/presence of ridges of mature stem. Leaf characters viz. leaf lobation, colour, leaf vein colour, leaf margin colour, waxiness, leaf shape, leaf apex shape, distance between lobes, petiole colour, petiole wing colour of matured leaf exhibited a wide variation. Variations were not found for stem cross section at the base and position of leaf. For underground tubers, variations were observed in most of the morphological characters. Variation in morphological characters of greater yam cultivars could be used as an index in varietal identification of greater yam for developing high yielding cultivars.