Sexual fertility of fortyFusarium strains from the EuropeanFusarium sambucinum project

Abstract
Fungus strains designated asFusarium sambucinum, F. torulosum, orFusarium sp. nov. were crossed withMAT1-1 andMAT1–2 tester strains ofGibberella pulicaris. Of the 40 field strains that were crossed with the tester strains, 13 strains produced fertile crosses and 27 strains did not produce fertile crosses. One strain designated asF. torulosum was fertile with a tester strain ofG. pulicaris, suggesting that this is an intraspecies cross and that the strain isG. pulicaris, and, consequently,F. sambucinum rather thanF. torulosum. The lack of fertile crosses between tester strains and 27 of the 40 field strains suggests that these strains are notG. pulicaris. Although the ability to form a fully fertile cross with a tester strain can determine the species of a fertile strain, it is more problematic to exclude a strain only because it is infertile.