Abstract
Mature ascospores of the pear scab fungus Venturia nashicola were produced when mycelial suspensions of two compatible isolates were mixed on the culture media employed and incubated at 5C in the dark for about six months. The inheritance of resistance to thiophanate-methyl, benomyl and MBC was demonstrated experimentally using a technique developed for the production of ascospores. Progeny segregation of the cross between the resistant isolate and the sensitive one fitted a 1:1 ratio, indicating that resistance is under control of a major gene. Additional crosses among resistant isolates suggest the involvement of multiple major genes for different degrees of resistance.
