AFLP fingerprinting of Kentucky bluegrass (Poa pratensis L.) from undisturbed Dutch grasslands: implications for conservation

摘要

Undisturbed grasslands are considered rich sources of promising genotypes for the development of new varieties of Kentucky bluegrass (Poa pratensis L.). Grasslands that have not been resown with commercial cultivars nor treated with high doses of nitrogen fertilizer have become rare in the Netherlands. In 1998, a survey among farms still in agricultural use revealed the existence of about 50 such grasslands that were designated "old Dutch grasslands". AFLPs were used to study the genetic diversity among 194 plants from 12 old Dutch grasslands in comparison with 81 plants from undisturbed grasslands from 5 Dutch nature reserves and 220 plants from 11 reference cultivars that played an important role in the development of Dutch grasslands. Of the 275samples from undisturbed grasslands, 151 plants (55%) displayed genotypes that could be matched with those of reference cultivars or were observed in multiple grasslands, suggesting a widespread occurrence of different genotypes. Based on the observed extent of overlap in genetic diversity and because grasslands from nature reserves are already under protective measures, no specific in situ conservation measures were recommended for old Dutch grasslands. However, from the group of grassland plants thatcould not be matched with the reference cultivars, 46 genotypes unique to single grasslands and 13 genotypes observed in multiple grasslands were maintained for ex situ conservation in order to extend the small genebank collection of Kentucky blue-grassin the Netherlands.