Inheritance of bacterial blight resistance in rice

Abstract

We studied the inheritance and allelic relationships of the genes for resistance to bacterial blight in three rice breeding lines IR1330-3-2, IR944-102, IR1698-241, and in three cultivars, Pelita I/1, Kele, and Chinsurah Boro II. The study of F₁, F₂, F₃, and reciprocal backcross populations of crosses between resistant parents and the susceptible cultivar Taichung Native 1 (TN-1) revealed that resistance in these rices is under monogenic control. The resistance of IR 1330-3-2 and Pelita I/1 is incompletely dominant, whereas that of Kele and Chinsurah Boro II is recessive. The genes that govern resistance in IR944-102 and IR1698-241 show recessive gene action with the method of inoculation used in this study. Evidence from allele tests with known genes for resistance indicates that Xa4 governs resistance in IR1330-3-2 and Pelita I/1, and xa5 in Kele and Chinsurah Boro II. Rice breeding lines IR944-102 and IR1698-241 have the same gene for resistance which is closely linked to Xa4.