Genetic relationships in Chaenomeles (Rosaceae) revealed by isozyme analysis

Genetic relationships were studied among four taxa in the genus Chaenomeles using isozyme analysis. The band patterns obtained with six polymorphic isozyme systems provided 108 reliable markers, which were scored as unordered multistate traits. A cluster analysis as well as a multidimensional scaling analysis grouped the taxa in agreement with previously published results obtained with RAPD (random ampli®ed polymorphic DNA) analysis; C. japonica and C. cathayensis were the most distantly related species, whereas C. speciosa took an intermediate position together with the hybrid taxon C. x superba. Similarity matrices obtained with isozymes and RAPDs, respectively, were closely correlated, r ˆ 0.74. The previously noted low level of RAPD variability in C. cathayensis was indicated also with isozymes. However, the isozyme data were less ef®cient than the RAPD data for intraspeci®c grouping of the genotypes according to the origin of the plant material. # 2000 Elsevier Science B.V. All rights reserved.