Identification of New Resistant Sources to Rice Gall Midge Biotype 4M under Endemic Situations
S. Malathi *
Regional Agricultural Research Station, Warangal, Professor Jayashankar Telangana Agricultural University, Telangana, India and Agricultural College, Warangal, Professor Jayashankar Telangana Agricultural University, Telangana, India.
R. Shravan Kumar
Regional Agricultural Research Station, Warangal, Professor Jayashankar Telangana Agricultural University, Telangana, India.
A. P. Padmakumari
ICAR–Indian Institute of Rice Research, Rajendranagar, Hyderabad, Telangana, India.
*Author to whom correspondence should be addressed.
Abstract
The Asian rice gall midge, Orseolia oryzae (Wood-Mason), is a major endemic insect pest in the Warangal region of Telangana, India, where it causes substantial yield losses in rice. The present investigation was conducted during the 2020 wet season at the Regional Agricultural Research Station, Warangal, under the auspices of Professor Jayashankar Telangana Agricultural University, Telangana, India. The study aimed to evaluate 68 rice genotypes, together with standard check varieties, for their resistance to gall midge infestation. The entries were screened under natural field conditions using the standard screening method and assessed based on per cent plant damage (PD) and per cent silver shoots (SS). Among the resistant checks, Aganni and RP 2068-18-3-5 recorded moderately resistant reaction (score 3), Abhaya and Kavya showed susceptible reaction (score 7) while W1263 showed moderately susceptible reaction (score 5), based on silver shoot incidence. The resistant checks recorded 20.0-100.0% PD. Among the test genotypes, none of the test genotypes exhibited resistant reaction based on plant damage and silver shoot damage. Only five genotypes - IBT WGL-5, IBT WGL-8, IET 28333, KNM 11593, KNM 11586 with silver shoot damage from 1.0 to 4.7% (score 3) were found moderately resistant against gall midge biotype 4M. Among these, IBT WGL-5 and IBT WGL-8 recorded comparatively lower plant damage (15.0%) and may serve as useful sources for further breeding and validation studies.
Keywords: Asian rice gall midge, GMB 4M, resistance sources, rice genotypes, screening, silver shootdamage, Standard Evaluation System (SES).