Genetics of resistance for bacterial leaf blight in high yielding popular Indica rice (Oryza sativa L.) cultivar of Eastern Uttar Pradesh

An experiment was conducted to examine the inheritance of bacterial leaf blight disease resistance in rice cultivars TN-1 (used as susceptible check), HUR 4-3, RP BIO-226 and their six populations of cross HUR 4-3 × RP BIO-226 against the strain BX043 (wild type) of pathogen Xanthomonas oryzae pv. oryzae. The resistant cultivar RP BIO-226 showed 3.76 % disease severity, while susceptible cultivar HUR 4-3 showed 54.79% disease severity and susceptible check TN-1 showed 75.17% disease severity against the pathogen Xanthomonas oryzae pv. oryzae. The area under disease progress curve (AUDPC) of resistance cultivar was 59.57, which was significantly less than the susceptible cultivar (638.28) and check (885.85). The F1 hybrid populations were observed to be resistant with average disease severity 9.03% and AUDPC 126.60. The F2 (segregating) and back-cross (B1 and B2) populations were phenotypically classified into three distinct classes as highly resistant or resistant, moderately resistant, and moderately susceptible or susceptible in the ratio 13:3, 1:1 and 1:0 (non-segregating type), respectively which is mainly due to cumulative effects of three resistant genes Xa21, xa13, and xa5 and their chi square value was 4.09 and 1.34 indicating that observed data are in accordance with expected ratio and followed the inhibitory gene action and Mendelian pattern of inheritance of resistance for bacterial leaf blight in rice.