|Department of Plant Pathology,
College of Agriculture and Research Station, Janjgir, Champa - 495 668, Chhattisgarh, India
*Department of Plant Pathology, Indira Gandhi Krishi Vishwavidyalaya, Raipur - 492 012, Chhattisgarh, India
|In the present studies response of resistance genes identified against BB is studied under Chhattisgarh condition. Twenty nine genotypes, with resistance genes mentioned in parenthesis i e IRBB-1, IRBB-3, IRBB-4, IRBB-5, IRBB-7, IRBB-8, IRBB-10, IRBB-11, IRBB-14, IRBB-50, IRBB-51, IRBB-52, IRBB-53, IRBB-54, IRBB-55, IRBB-56, IRBB-57, IRBB-58, IRBB-59, IRBB-60, IRBB-21, Zenith, BJ-1, IR-20, Jawa-14, Tetep,TKM-6, RP Bio-226 and TN-1 were evaluated under 5 stress conditions [dry, wet/saturated water, alternate wet and dry (24 hours wet and 24 hours dry), low humidity and high humidity conditions] in pot studies during kharif and rabi seasons. After artificial inoculations with the bacterial suspension of Xanthomonas oryzae pv. oryzae, the causal organism of BB, observations for disease development were recorded at 7, 14 and 21st days. The genotypes IR-20 (with Xa 4) and RP- Bio 226 recorded least percent severity in all the stress conditions during the three observations recorded at 7 days intervals. Confirming that the resistance factor in these genotypes are expressive under the stress susceptible TN-1 and Tetep (Xa 1 + Xa 2 + Xa 12); IRBB-10 (Xa 10); IRBB-11(Xa 11); IRBB-14 (Xa 14) and IRBB-50 (Xa 4 + xa 5) showed susceptibility in all the stress conditions after 21st day, the most accepted resistance evaluation period under artificial inoculated conditions. The genotypes IRBB-56 (Xa 4 + xa 5 + xa 13); IRBB-55 (Xa 13 + Xa 21); IRBB-59 (Xa-5 + xa-13 + Xa-21) and IRBB-21 (Xa 21) also showed resistance all the stress conditions. Non significant interaction between the genotype and different stress conditions were recorded for percent disease severity at 7 days observation. However, 14th and 21st day observation there were interactions were significant between the stress condition and genotype clearly indicating the cumulative influence of G x E on resistance expression and percent disease appearance. The genotypes TN-1 and Tetep (Xa 1 + Xa 2 + Xa 12); TKM-6, IRBB-10 (Xa 10); IRBB-11 (Xa 11); IRBB-14 (Xa 14) and IRBB-50 (Xa 4 + xa 5) showed moderately resistance to susceptibility score.