Assessment of diversity using agro-morphological traits for selecting a core sample of Papua New Guinea taro (Colocasia esculenta (L.) Schott) collection

Agro-morphological variation in the taro germplasm of Papua New Guinea was estimated using 18 polymorphic descriptor states to aid in the selection of a core sample for the formation of a regional core collection currently being assembled under the Taro Network for Southeast Asia and Oceania. A total of 276 accessions were stratified into five homogenous groups by using a hierarchical approach according to botanical variety (dasheen or eddoe), altitude ( high or low) and stolon formation ( present or absent). In selecting the core sample, the eddoe group were directly included because of their rarity in the germplasm collection. While, a ten per cent sample fraction within each group of the dasheen types were selected based on principal component scores. A total of 31 accessions were selected for the core sample. Multivariate analysis of the core sample revealed wide variation, which was mainly influenced by botanical variety, plant height, lamina colour and variegation, petiole colour, corm shape, corm weight and palatability. Cluster analysis identified two homogeneous clusters based on predominant characters that should be useful to breeders. The results obtained in this study provide useful background information for further development of a national core collection.