Genetic and phenotypic variations among F1 progenies of Arthroderma benhamiae.

The genotypes and phenotypes of 77 isolates derived from ascospores produced from two genetically different Arthroderma benhamiae were studied. Specifically, mitochondrial DNA (mtDNA) type, nuclear DNA (nDNA) type, mating type, colony texture, growth rate, urease activity, red pigmentation and hair perforation were examined. The nDNA types based on the restriction fragment length polymorphism (RFLP) in the internal transcribed spacer (ITS) region of ribosomal RNA (rRNA) genes and mating types were inherited from parents independently. mtDNA type was inherited from only one parent. All the phenotypes, except hair perforation and mating type, showed great variations. Those seemed not to be a conclusive factor for species identification. Additionally, these characteristics appeared in variable combinations suggesting that they are not interrelated. The intensity of red pigmentation varied even within a colony, implying that it is not a strain-specific characteristic. Hair perforation was observed in isolates of all but one atypical strain, and therefore could be one characteristic of this species.