Inheritance of resistance to blast(Pyricularia grisea Sacc.) in Korean weedy rice(Oryza sativa L.)

The blast resistance of 24 accessions of Korean weedy rice was evaluated using eleven Korean blast fungus races. Three accessions which showed resistant to all the blast races tested were crossed with Nagdongbyeo which showed susceptible to blast and late heading. Inheritance of resistance to blast and linkage relationship between blast resistance and heading time were studied using KJ-101, KJ-301, KI-197 and KI-409 races in F₂ and BC₁F₁ populations. Geumleungaengmi 33, Kanghwaaengmi 11 and Ssalsharei of short grain Korean weedy rice were resistant to all eleven blast races used. Geochangaengmi 12 of short grain type and Guryeaengmi 9 of long grain type were resistant to ten blast races. The resistance to four blast fungus races was found to be controlled by two dominant genes in Geumleungaengmi 33, four dominant genes in Geochangaengmi 12, and one dominant gene in Ssalsharei. The linkage relationship was found between the resistance gene of Geumleungaengmi 33 to KJ-101 race and the late heading with recombination value of 23.0±.4.0%.