GENETIC-ANALYSIS OF COCHLIOBOLUS-HETEROSTROPHUS BEIGE MUTANT

A new class of colour mutant of Cochliobolus heterostrophus was isolated. The colony colour was beige (greyish yellow to greyish orange) and could be distinguished from previously reported colour mutants. In crosses of mutant with wild type strains, four classes of offspring were obtained. Two classes were parental types, and the other two were unlike either parent. The four types were present in a I:I:I:I ratio, implying that two unlinked genes were involved in phenotypic alteration. One gene was involved in a yellow-brownish grey pigmentation of mycelia, and was designated as Ybg1. The second gene was involved in melanin-deficiency, and was an allele of Alb3.