Published online by Cambridge University Press: 01 April 2008
A total of 1968 accessions of cultivated eggplants, belonging to Solanum melongena and Solanum aethiopicum and procured from the IVC/JAAS (Nanjing) and IVC/ZAAS (Hangzhou), China, were examined for 23 morphological traits, such as characteristics of plant, stems, leaves, flowers, fruits and original geographic information. A comprehensive numerical classification methodology, including two types of genetic distance, viz. Mahalanobis (Ma) distance and Euclidean (Eu) distance; four clustering methods, viz. unweighted pair group average (UPGA), Ward's (W), complete linkage (CL) and single linkage (SL) methods; three sampling strategies, viz. random (R), preferred (P) and deviation (D); and four sampling sizes (10, 15, 20 and 30% of initial collection), was used to divide all accessions into main groups and subgroups for the establishment of candidate collections. The evaluation of these candidate collections showed that a combination of Eu distance, UPGA clustering method, and R or P sampling strategy with sampling size at 15–20% was suitable for establishing the core collection, providing an adequate and representative genetic diversity of the initial collection of the cultivated eggplants.