Vol. 11, Special Issue 6 (2022)

Author(s):
Kavitha G, Reddi Sekhar M, Mohan Reddy D, Reddy VLN, Kalyani MB, Sudhakar P and Senguttuvel P

Abstract:
Drought stress has become more important abiotic factor affecting rice yield under present changing climate conditions. IR58025B is a maintainer line of widely used WA CMS line IR58025A in commercial rice hybrids production in India. Most of the rice hybrids released for the diverse ecosystem conditions using three-line system. Consequently, these derived hybrids suffer drastic yield decline under moisture stress conditions. To facilitate the efficient use of complex polygenic traits in hybrid rice molecular breeding research, we undertook development of introgression lines in background of IR58025B with tolerance to moisture stress by introgression of major QTL qDTY_3.1controlling grain yield under moisture stress. The present study reports the development and evaluation of 230 introgression lines (BC₂F₂) lines in IR58025B background for improvement of grain yield under moisture stress condition. Among 230 ILs, 24 introgression lines were found positive for qDTY_3.1 and negative for rf3. Promising BILs exhibited earliness of 7 days under moisture stress in comparison to the recurrent parent. Grain yield advantage of 8.54g to 10.78g was recorded among selected BILs compared to IR58025B under moisture stress condition. This suggested that the efficacy of introgressed drought tolerant QTL qDTY_3.1 in enhancing grain yield under moisture stress conditions. Further, breeding lines of IR58025B possessing qDTY_3.1 could also serve as good donors for development of tolerant rice hybrids under drought stress.