Rhizoctonia solani AG5 and Its Offspring – Morphology and Sensitivity to Fungicides

These studies aimed to identify differences and similarities within the progeny of <i>Rhizoctonia solani</i> AG5, which arose from basidiospores produced by maternal strain ID23. The following characteristics were analyzed: appearance mycelium (color, structure, zonation, presence sclerotia), growth rate (at 10°C, 20°C, 30°C), fungicide sensitivity, hyphal structure. mycelial color <i>R. AG5 ranged white/cream light dark brown. structure may be compacted or flattened with visible zoning fluffy brown sclerotia on colony surface. Homokaryons heterokaryons derived homokaryons analyzed constructing a phylogenetic tree using morphological data. Single basidiospore-grown isolates formed separate subclade, most grouped isolate; however, them created subclade. In addition, grown in germinated at low temperatures their own group, but some exceptions. This shows divergence parameters subsequent generations generations. optimal temperature for was found between 20°C 30°C. exceptions strains obtained that refrigerated temperatures. For these samples, 10°C temperature. hyphae characterized branching an almost right angle septum site constriction branch itself. mean diameter 2.93–15.60 μm, depending age hyphae. fungicidal compounds concentration 10 ppm had no significant effect activity tested strains, whereas tenfold increase dose reduced ability isolates. fungicides containing azoxystrobin, thiuram, thiophanate-methyl resulted reduction only case azoxystrobin cases, it completely inhibited (thiophanate-methyl).