CHROMOSOMAL-ABNORMALITIES ASSOCIATED WITH STRAIN DEGENERATION IN THE CULTIVATED MUSHROOM, AGARICUS-BISPORUS

Commercially grown strains of the button mushroom, Agaricus bisporus, on occasion produce sectors that display undesirable phenotypes, Such sectors show altered compost colonization, have reduced yield, and pro duce inferior quality mushrooms, The current study compared isolates o f eight irreversible sectors to the original cultivator (U1) from whic h they arose, Gene-specific and anonymous DNA probes were used to iden tify RFLPs and chromosomal differences (CHEF analyses) between the U1 sectors and the normal U1 cultivar. A number of differences were noted including loss of heterozygosity at specific loci, deheterokaryotizat ion, somatic recombination, chromosomal loss, chromosomal length polym orphisms, possible chromosomal translocations, and changes in copy num ber of the ribosomal DNA repeat. (C) 1996 Academic Press, Inc.