Developing an appropriate strategy to assess genetic variability in plant germplasm collections

The value of molecular biology for monitoring the genetic status of germpla sm collections is subject to practical limitations. The large number and va riability of accessions held usually dictates the approach that can be empl oyed. A quick, simple but reliable molecular protocol must be combined with an appropriate strategy for handling large sample sizes. In this study, IS SR-PCR was used to reveal genetic variability within and between accessions held in a collection of lupin germplasm. Pooling of DNA from individuals w ithin accessions was found to be the most appropriate strategy for assessin g large quantities of plant material. Band profiles generated from pools co ntaining five individuals were fully representative of all constituent indi viduals used in the mix. Pools comprising 10 or 20 individuals, however, so metimes failed to contain minor bands that had been present only in the pro file of one individual. Variation was observed between pools containing fiv e different genotypes from the same accession. Routine large-scale screens are required to assess the genetic diversity and homogeneity of the lupin g ermplasm collection held in Reading. It is concluded that 2-3 pools of five genotypes may be sufficient to represent the genetic variability within an d between accessions in the lupin and similar collections.