Characterization of North American Armillaria species by nuclear DNA content and RFLP analysis

Abstract

Twenty-six isolates representing nine North American Armillaria species were investigated with flow cytometry and RFLP (restriction fragment length polymorphism) analyses to determine their nuclear DNA content and RFLP profile. Three putatively diploid isolates of A. ostoyae, A. gemina, A. calvescens, A. sinapina, A. mellea, A. gallica, A. nabsnona, and North American Biological Species (NABS) X were analyzed, and two putatively diploid isolates of NABS XI also were analyzed. Nuclear DNA contents of Armillaria species were 0.11–0.17 pg per nucleus (55–84 X 106 bp/C), depending on species. Among the nine North American Armillaria species tested, A. ostoyae, A. gemina, and A. mellea possessed relatively small nuclear DNA contents (0.11–0.12 pg per nucleus), whereas A. gallica possessed a relatively large nuclear DNA content (0.17 pg per nucleus). A. nabsnona has a slightly larger nuclear DNA content (0.13 pg per nucleus) than A. ostoyae, A. gemina, and A. mellea. Other species (A. calvescens, A. sinapina, NABS X, and NABS XI) possessed moderate nuclear DNA contents (ca 0.15 pg per nucleus). Polymerase chain reaction (PCR) and RFLP of the intergenic spacer region-1 (IGS-1) generated banding patterns for nine Armillaria species. In addition to previously reported banding patterns, new banding patterns are presented for A. gemina, A. calvescens, A. mellea, and A. gallica.