CONGRUENCE OF CHLOROPLAST DNA RESTRICTION SITE CHARACTERS WITH MORPHOLOGICAL AND ISOZYME DATA IN SOLANUM SECT LASIOCARPA

Chloroplast DNA restriction site characters were analyzed cladisticall y in species of Solanum sect. Lasiocarpa (subg. Leptostemonum), and re sults were compared with previously published analyses of morphologica l and isozyme characters. Cladistic analysis of the chloroplast DNA re striction site characters resulted in a single tree in which two main clades were detected: one comprised three morphologically distinct low land Amazonian species, and the other included the Andean and the two Asian species. Character congruence among the three data sets was asse ssed with a previously described index and with a permutation test der ived from this index. Taxonomic congruence was evaluated with a measur e modified from that of another researcher. The three assessments of c ongruence indicate that the chloroplast DNA and isozyme analyses are t he most incongruent, but they differ as to their evaluation of relativ e (in)congruence for the other comparisons. Combining the three data s ets resulted in two most parsimonious trees whose topologies incorpora te elements from each of the separate analyses. The combined chloropla st DNA and morphological analyses support a previously proposed hypoth esis that the two Asian species are sister taxa and of a single origin , rather than having originated separately from two distinct South Ame rican groups.