Evaluation of F5 Breeding Lines Derived from Pranahitha for Bacterial Leaf Blight Resistance and Yield Performance

Abstract

Rice is the second most important crop in the world. There is a need to increase the production and productivity of rice to meet the demand of a growing population at an alarming rate. Biotic and abiotic stresses are the major constraints for achieving the required yield. Bacterial leaf blight represents one of the most significant biotic constraints limiting rice productivity across major rice-growing regions. The present study was undertaken to assess the phenotypic response of fifty breeding lines derived from the cross (Pranahitha//ISM/MTU1010 NIL) against this disease. The experiment was carried out under controlled glasshouse conditions at the Regional Agricultural Research Station (RARS), Polasa, Jagtial. During the Kharif season of 2021, the breeding lines were artificially inoculated with a bacterial leaf blight isolate (DX-020) using the leaf clipping technique. Among the fifty F₅ breeding lines evaluated, twenty-seven lines exhibited a resistant reaction, each recording a disease score of 1. A further eight lines were categorised as moderately resistant, with a disease score of 3. Notably, the twenty-seven resistant lines also demonstrated superior grain yield performance. Consequently, these lines were selected for advancement to subsequent generations. The findings of this investigation indicate that phenotypic selection under glasshouse conditions is an effective approach for identifying bacterial leaf blight-resistant genotypes. Moreover, the high-yielding lines identified in this study are anticipated to perform favourably in field evaluations and, ultimately, under farmers’ cultivation conditions, while maintaining a satisfactory level of resistance to bacterial leaf blight.