ｒＤＮＡ ＩＴＳ領域の多型によるいもち病菌の類別

Abstract

Using 27 strains of Pyricularia grisea from various hosts, the internal transcribed spacer regions (5.8S plus ITS1 and ITS2) of nuclear ribosomal DNA (rDNA) repetitive units were analyzed by the RFLP (restriction fragment length polymorphism) and/or SSCP (single strand conformation polymorphism) method. The ITS regions of 9 rice strains belonging to 8 races were amplified by the polymerase chain reaction (PCR) and restricted with 9 enzymes (Acc II, Alu I, Hae III, Hha I, Mbo I, Msp I, Rsa I, EcoR I and Hind III). There were no polymorphisms among those strains, suggesting that the rice strains in Japan are in a homogeneous genetic group. This was confirmed with a mitochondrial small rDNA and a mitochondrial large rDNA fragment. On the other hand, the P. grisea from various hosts showed polymorphisms within the ribosomal ITS regions by RFLP and/or SSCP using 6 restriction enzymes (EcoR I, Hae III, Hha I, Mbo I, Msp I and Rsa I). The results divided the P. grisea strains into 4 groups, namely rice group, crab grass group, Manchurian wild rice group and mioga group. The rice group included strains from other host plants: Italian millet, common millet, finger millet, goose grass, Japanese millet, weeping lovegrass, panicum (nukakibi), Italian ryegrass and harding grass.