Variation in the enzyme esterase within and between Tulipa species; usefulness for the analysis of genetic relationships at different taxonomical levels

Intra- and interspecific variation in bulb scale esterases of Tulipa species were investigated to determine the usefulness of this marker for the assessment of genetic variation within the genus Tulipa. At the population level, esterases appeared to be suitable markers. Different bulbs of a population, which were analyzed for polymorphisms in their esterases using native PAGE next to other accessions from the same species, generally formed a separate group after cluster analysis. In some of these cases, genetically related accessions clustered within the population cluster. Within section Tulipa, which consists of relatively closely related species, esterases also proved to be useful for analysis of genetic variation at the species level, since the accessions from each species formed separate clusters. However, within section Biflores, which consists of more distantly related species, cluster analysis on the basis of esterases did not reveal clustering of all species. Clustering of the accessions within both sections on the basis of bulb scale esterases was compared with relationships found using morphological data. The species of section Tulipa did not form separate clusters after analysis of the morphological data, which is in contrast to the results from esterase analysis. However, all accessions of section Biflores clustered together per species based on the morphological variation. (C) 1998 Elsevier Science Ltd. All rights reserved.