Hybridization between two biotypes of Gremmeniella abietina var. abietina in artificial pairings

Summary The ability of the European biotypes A and B of Gremmeniella abietina var. abietina to hybridize in artificial pairings was tested. Using three types of molecular markers progenies with parental markers mixed indicating that the two biotypes can hybridize were observed. However, the resulting progeny had a low rate of successful germination, grew poorly on artificial medium and one was most probably a partial diploid or heterokaryon. Thus, both biotypes are genetically distinct populations and should be described as separate species as soon as sufficient discriminating information is available.