Rice (Oryza sativa L.) is a crucial food crop, but its productivity is greatly affected by insect pests, particularly the yellow stem borer, Scirpophaga incertulas (Walker). This study evaluated rice cultivars for resistance to this pest under natural field conditions during the Rabi 2025-26 season at the Regional Agricultural Research Station (RARS), Warangal, Professor Jayashankar Telangana Agricultural University (PJTAU). Thirty rice cultivars, together with seven resistant and susceptible checks, were evaluated in a randomised block design (RBD) with two replications. Yellow stem borer (YSB) damage was recorded at the vegetative stage at 30 and 50 days after transplanting (DAT) and at the reproductive stage. Based on dead-heart incidence, five cultivars were classified as highly resistant, seven as resistant, ten as moderately resistant, seven as moderately susceptible, and one as susceptible. Based on white-ear incidence, five cultivars were highly resistant, seven were resistant, nine were moderately resistant, seven were moderately susceptible, and two were susceptible. WGL-1957 recorded the lowest dead-heart incidence and the highest grain yield, whereas IET 29877 recorded the lowest white-ear incidence and the second-highest grain yield. These resistant cultivars may serve as donors in breeding programmes for yellow-stem-borer resistance and may support integrated pest management strategies.
Akkireddy Sahithi, A. Reddy, R. Kumar et al.· Uttar Pradesh Journal of Zoo...· 0 citations
Bacterial leaf blight, caused by Xanthomonas oryzae pv. oryzae, is an important disease of rice that can substantially reduce crop performance under favourable disease conditions. The present study was conducted to identify elite rice lines resistant to bacterial leaf blight using phenotypic evaluation supported by molecular marker analysis. Thirty elite rice lines, together with the resistant check Improved Samba Mahsuri and the susceptible check TN-1, were evaluated under field conditions at the Regional Agricultural Research Station, Warangal, during Kharif, 2025. Artificial inoculation was performed using the leaf-clipping method, and disease reaction was recorded 15 days after inoculation according to the IRRI Standard Evaluation System. Molecular screening was performed using the pTa248 marker linked to the Xa21 resistance gene and the xa13 promoter marker linked to the xa13 resistance gene. Phenotypic screening showed that three lines, WG-GP-375, WG-GP-377 and WG-GP-378, exhibited a highly resistant reaction, while WG-GP-376 showed a resistant reaction. Eight lines were moderately susceptible, fifteen were susceptible and three were highly susceptible. Molecular analysis detected the Xa21 resistance allele in all four phenotypically resistant lines, whereas the xa13 resistance allele was detected in WG-GP-375, WG-GP-377 and WG-GP-378. The combined phenotypic and molecular assessment identified WG-GP-375, WG-GP-376, WG-GP-377 and WG-GP-378 as useful sources of bacterial leaf blight resistance. These lines may be considered for further validation and use in rice breeding programmes aimed at improving resistance to bacterial leaf blight.
A. Mahveen, A. Srijan, G. Seshu et al.· Journal of Advances in Biolo...· 0 citations