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

Abstract

Agro-morphological variation in the taro germplasm of Papua New Guinea was estimated using 18 polymorphicdescriptor states to aid in the selection of a core sample for the formation of a regional core collection currentlybeing assembled under the Taro Network for Southeast Asia and Oceania. A total of 276 accessions were strati-fied into five homogenous groups by using a hierarchical approach according to botanical variety (dasheen oreddoe), altitude (high or low) and stolon formation (present or absent). In selecting the core sample, the eddoegroup were directly included because of their rarity in the germplasm collection. While, a ten per cent samplefraction within each group of the dasheen types were selected based on principal component scores. A total of 31accessions 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 predominantcharacters that should be useful to breeders. The results obtained in this study provide useful backgroundinformation for further development of a national core collection.