Genetic basis of fungicidal Carboxin resistance in Aspergillus amstelodami

ABSTRACT<br /> A Sample of 63 mutants resistant to the fungicide carboxin (Vitavax) was isolated in the parental strains A76 (bwA nicA, brown conidia, nicotinic acid-requiring) and AZG131 (wA lysA azgA131, white conidia, lysine-requiring and resistant to 8-azaguanine) of the ascomycetous fungus Aspergillus amstelodami. All mutants were normal in their morphology and recessive to their respective wild type alleles. Complementation tests in heterokaryons among the mutants put them all in a single gene designated carA (for resistance to carboxin) as the first gene of its kind to be identified in A. amstelodami. Haploidization analysis has shown that carA is not linked in any of the chromosomes I, II, III, IV or VII, but its linkage relation to the other groups (V, VI, VIII or IX) recognized in this fungus was not determined.