ELECTROPHORETIC KARYOTYPE ANALYSIS OF BOTRYTIS-CINEREA

The karyotypes of five strains of Botrytis cinerea were analysed by pu lsed field gel electrophoresis (PFGE). None of the five chromosome pat terns were identical and all five strains contained one or several min ichromosomes of variable length. Considering that some of the chromoso mal bands represent unresolved doublets, the total genome size of the five strains was estimated to vary between at least 33.9 and 39.7 mega basepairs (Mbp). Hybridization of blots of pulsed field gels with rDNA and beta-tubulin probes revealed that these hybridize with the same c hromosomal band. Chromosome-specific probes were isolated hybridizing to chromosomal bands 9 and 11 of strain SAS56. The latter two probes h ybridized to only two of the five strains tested. The results are disc ussed in relation to the genome plasticity and variability of filament ous fungi.