Studies on the inheritance of leaf blast resistance in rice

Abstract

Studies on the inheritance of leaf blast resistance in seven differential varieties of rice tested against two Indian isolates of the international races IA-11 add ID-1 of Pyricularia oryzae Cav. under standardized experimental conditions revealed the presence of three dominant genes, one each in Zenith. Tetep and Ginga conferring resistance to IA-11 and two, one each in Zenith and Tetep, to the race ID-1. The genes of Zenith were independent of those of Tetep. C.l. 5309 possessed inhibitory genes inhibiting the resistance of Zenith but not of Telep. Mode of segregation of resistance o Norin 20 to the race IA-11 was found to be anamolous. Studies on the crosses among susecptible varieties showed the existence of dominant genes conferring susceptibility, two each in P.I. 180061 and Yakeiko. This is a new feature of the present studies and its utility in evolving homozygous recessive resistant varieties have been pointed out.