VIEW ARTICLE

Genetic Control of Basidiospore Formation by Isolates of Lenzites trabea. Terry L. Amburgey, Former Graduate Research Assistant, Department of Plant Pathology, North Carolina State University, Raleigh 27607, now Pathologist, Forest and Wood Products Disease Laboratory, Southern Forest Experiment Station, U.S. Forest Service, Gulfport, Mississippi 39501. Phytopathology 60:951-954. Accepted for publication 14 January 1970. DOI: 10.1094/Phyto-60-951.

A model is proposed to account for the formation of fertile basidiocarps by monobasidiospore isolates of Lenzites trabea. It involves two assumptions. (i) Such isolates are derived from binucleate basidiospores whose nuclei are homozygous for sexual incompatibility but heterozygous at other loci. They do not produce clamp-connections even though they are heterokaryotic. (ii) Fusion of dissimilar nuclei in the basidia is followed by meiosis, giving rise to recombinant nuclei and hence variation in such traits as capacity to cause decay. Variation in capacity to cause decay of wood and to produce cellulolytic enzymes among selected monobasidiospore and mono-oidial isolates indicate that (i) fruiting monobasidiospore isolates have two nuclear types that are homozygous at the locus governing sexual incompatibility but are heterozygous at other loci; and (ii) genetically controlled variation among the secondary and tertiary homokaryons obtained from a given source appears to result both from mutations and genetic recombination during formation of basidiospores.