Morphological characterization of cultivated and wild yam (Dioscorea spp) in Malawi Msowoya-Mkwaila Wezi E.*, Changadeya Wisdom J.*, Ambali Aggrey J. D.** *Department of Biological Sciences, University of Malawi, Chancellor College, Zomba, Malawi **NEPAD African Biosciences Initiative, Policy Alignment and Programme Development Directorate, NEPAD Agency, c/o CSIR Building 10F, Meiring Naude Road, Brummeria, Pretoria, Republic of South Africa # Corresponding author: Wisdom Changadeya
Online published on 21 November, 2013. Abstract Root and tuber crops are an important source of food and cash worldwide. In Malawi, the potential of yams in crop diversification to achieve food security has long been identified. Collections of cultivated yams have been made and conserved ex-situ but the accessions have not been fully characterized. This study used IPGRI(1997) yam descriptors and a key by Hanon et al., (1995) to characterize cultivated and wild yams (Dioscorea spp) collections in order to generate morphological profiles of the yams which can be used in the domestication and enhancement of the species. A total of 80 wild and 43 cultivated yam accessions were collected and assessed. Initial assessment of the yam collections showed that there is a considerable species diversity of yams in the wild and cultivated yams are well established though at small scale in the farms. Principal Component Analysis produced eight distinct groups of the yams with one group constituting all cultivated yams and the other seven groups representing different wild yams. Cluster Analysis revealed that the cultivated yams are highly similar (70%) but they are not duplicates except accession MSYC18 and MSYC 23. All the cultivated yam accessions in the study were identified as belonging to the species D. alata, the winged yam. The cultivated species classified earlier as D. rotundata and D. bulbifera were therefore misidentified. The yams were thus morphologically diverse with wide spectrum of characters that can be exploited by plant breeders. Top Keywords Cultivated yams, wild yams, morphological characterization, descriptors. Top |