Evaluation of Different Rice Varieties for Their Resistance Level against Rice Tungro Disease

Abstract

Rice tungro disease is a major viral disease that constrains rice production, especially when infection occurs during early crop growth. The present study evaluated the phenotypic reaction of 24 rice varieties, along with TN1 as the susceptible check and Vikramarya as the resistant check, against rice tungro disease under controlled glasshouse conditions at the Pathology glasshouse, ICAR-Indian Institute of Rice Research, Rajendranagar, Hyderabad, during 2023–24. Screening was conducted using the Standard Seedbox Screening Test with viruliferous green leafhoppers as vectors. Seedlings were inoculated at 15 days after sowing and evaluated 21 days after inoculation using the Standard Evaluation System (IRRI, 2013) disease-scoring scale. Disease index values were used to classify entries as resistant, moderately resistant or susceptible. The susceptible check TN1 showed high disease expression, confirming effective disease pressure during screening. Among the evaluated entries, Utri Rajapan, Utri Merah, ARC11554, Pankhari 203, TKM-6, Kataribhog, Tjempo Kijik recorded disease index values of 3.0, comparable with the resistant check Vikramarya, and were classified as resistant. Several entries, including ARC 12596, MTU 1010, ASD-8, Prasanna, IR-8, IR-22, Tampha Phou, Hassany, Barah, KNM 118 and JGL24423 has showed moderately resistant. The rice cultivars Pusa Basmati, Tapaswini, , DR29, RJNRH-10, RNR15048 and KNM 1638 were classified as susceptible. The results identify potential resistant donor entries that may be useful in rice breeding programmes, although further validation under field and molecular screening conditions is required.