MUTATION SPECTRUM IN THE FUNGUS CONIOCHAETA VELUTINA

Abstract

Auxotrophic, n~orphological, sensitive and suppressor mutant strains of Co7?iocbnetn vel~rti~zn are dcscribed. Of 1 3 3 1 auxotrophic mutants isolated, all but 58 have been characterized as to their specific rcquiren~cnn. T h e mutation spectrum obtained on malt medium differs in several respects from that on complete medium. Arginine, adenine, cysteinc, rnethionine, histidine and pyrimidine requiring mutants were most frequently isolated. Of 1 2 diauxotrophs tested gc~letically, 7 proved to be double mutants, but the remaining 5 behaved genetically as single mutann rvith a double requirement. Four of these required both adenine and histidine for growth and [he other both pl~enylalanine and ryrosine. Cystcine-sensitive murants and hisridinc-sensitive strains are dcscribed. Other mutann isolated included a variety of morphological, conidial and colour variants, UV-sensitive srrains, canavaninc-sensitive srrains and arginine-suppressor murations.

Mutants with Increased Sensitivity to Canavanine in the Fungus Coniochaeta velutina

“…From the above findings and some earlier observations (Tan, 1968;Paterson et al, 1969) a proposed metabolic relationship between the pyrimidine, arginine and proline pathways, with relevant genes and enzymes, has been formulated for Coniochaeta (Fig. 4).…”