Problems and Prospects of Rhizoctonia Diseases and Their Control in Japan

Abstract

Rhizoctonia solani in Japan is diveded into 8 anstomosis groups (AGs), and some of them include subgroups. The genetical homogenicity in the isolates of respective AGs has been studies by DNA-DNA reassociation kinetics. Plant pathogenic Rhizoctonias belong to AG 1-5, and they are isolated from the plants and soils in cultivated and uncultivated areas in Hokkaido. 日本產Rhizoctonia solani可分為8個菌絲融合羣 (anastomosis group, AGs)，部分融合羣並具有亞羣 (subgroups)。各AGs之菌株是以DNA-DNA再配對動力學 (DNA-DNA reassociation kinetics) 之方法研究其遺傳純一性 (genetical homogenicity)。具植物病原性的Rhizoctonias屬於AG 1-5，這些菌株均由北海道的耕地及未耕地的植物及土壞中分離而得。