Genetic diversity of the 'peruvianum-complex' (Lycopersicon peruvianum (L.) Mill. and L-chilense Dun.) revealed by RAPD analysis

For further genetic improvement of the tomato, it is essential to promote efficient collection, classification, preservation and utilization of the wild tomato species. To investigate the genetic diversity of the 'peruvianum-complex' (PC) species of highly polymorphic wild tomato relatives and the genetic relationship between the PC and the 'esculentum-complex' (EC) species including the cultivated, an RAPD analysis was carried out. A total of 435 RAPDs were obtained from 50 accessions of all the nine Lycopersicon species using only 10 random primers. Average genetic distances among the L. peruvianum accessions and among L. chilense accessions were larger than in any species of the 'esculentum-complex' (EC). In addition, the cluster analysis conducted by using the neighbor joining method showed that all the tested accessions were clearly divided into at least four main clusters consisting of the PC, the self-compatible EC, L. pennellii and L. hirsutum. This study demonstrated that the PC species had the largest genetic diversity in the Lycopersicon, and the genetic background of the PC was clearly different from those of the self-compatible EC species including the cultivated tomato. Moreover, it was suggested that the L. peruvianum accessions in northern Peru and the L. chilense accessions in southern Peru might have larger genetic variation in each species. From these results, it was concluded that the PC with such high and different genetic variation would have a potentiality to supply more and useful traits that are unknown at present for further tomato breeding.