Inheritance of the ability for ectomycorrhizal colonization of Pinus strobus by Laccaria bicolor

Abstract

Ectomycorrhizal colonization of Pinus strobus by monokaryotic and dikaryotic progeny of two strains of Laccaria bicolor was studied. The monokaryotic progeny of one strain formed ectomycorrhizae with between 1.5 and 80% of the available short roots. In the other case, the monokaryotic progeny formed ectomycorrhizae with between zero and 22% of the available roots. Percent ectomycorrhizal colonization by the dikaryotic progeny of both strains was continuously distributed from 30 to 84% in one case and from zero to 80% in the other. The results indicate that percent ectomycorrhizal colonization is polygenically controlled. A quantitative analysis of the dikaryotic progeny of one of the strains indicates that the degree of genetic determination, under the conditions of this study, are 19.7 and 4.4%. The interactive genetic component accounted for most of the genetically determined variation in this study.

Key Words:

• fungus
• genetics
• heritability
• symbiosis