Response of Rice Genotypes Carrying Gall Midge Resistance Genes against Asian Rice Gall Midge, Orseolia oryzae (Wood-Mason), in Mahabubabad, Telangana, India
Rice gall midge, Orseolia oryzae (Wood-Mason), is a major pest of rice that causes significant yield losses in India. The present study was conducted during Kharif 2023 at Krishi Vigyan Kendra, Malyal, Mahabubabad district, Telangana, to evaluate four rice genotypes carrying genes conferring resistance to gall midge (WGL-1119, IBT-WGL-2, Abhaya, and Aganni), together with TN-1 as a susceptible check, against the local gall midge population under natural infestation conditions. The experiment was laid out in a randomized block design with four replications. Gall midge incidence was assessed at 30, 50, and 75 days after transplanting (DAT) based on the percentages of plant damage and silver shoot damage, and the observations recorded at 50 DAT were used to score the genotypes according to the standard procedure. Significant differences were observed among the genotypes. Aganni, IBT-WGL-2, and WGL-1119 exhibited resistant reactions with low levels of infestation. At 50 DAT, Aganni recorded the lowest damage (2.50% plant damage and 0.52% silver shoots), followed by WGL-1119 (6.25% plant damage and 0.86% silver shoots) and IBT-WGL-2 (7.50% plant damage and 0.71% silver shoots). Abhaya showed moderate susceptibility, whereas the susceptible check, TN-1, recorded the highest infestation. Aganni and IBT-WGL-2 maintained stable resistance up to 75 DAT, whereas WGL-1119 showed a slight increase in plant damage but remained resistant based on silver shoot damage. Aganni and the pyramided lines IBT-WGL-2 (Gm4+Gm8) and WGL-1119 (Gm1+Gm4) were identified as promising sources of resistance to gall midge and as suitable resistant donors for breeding programmes. This is the first report on the response of these resistant genotypes to the gall midge population prevailing in Mahabubabad district, Telangana, India.