Induction of Useful Variability for Grain Color and Bacterial Blight Resistance in PAU 201, A Top High Yielding Variety of Rice

PAU 201, a very high yielding (10 Ton/Ha at farmers’ field) rice variety was released for cultivation in Punjab, India in 2007. Within two years of its release, it occupied 25% of the total area (2.8 mha) under rice. Despite its very high yield potential, it had two major defects i.e. red aleurone color and susceptibility to some of the pathotypes of bacterial blight (BB) pathogen (Xanthomonas oryzae pv. oryzae), leading to its withdrawal from cultivation in 2010. Due to its high popularity among the farmers, PAU 201 was an ideal choice for identifying mutational variants for grain colour.  Seeds of PAU 201 were treated with EMS mutagen at three concentrations viz. 0.6, 0.8 and 1%. About 850 M₁ panicles were harvested and planted as panicle to progeny M₂ rows. Sixty eight variants morphologically similar to PAU 201 but with white aleurone colour were bulked in M₅/M₆ generation and were evaluated for yield and its components, grain quality and reaction to different pathotypes of BB pathogen prevalent in the state. The mutant designated as RYT 3207 has desirable white aleurone layer, high grain yield and early maturity (by one week from PAU 201). Further, it is resistant to all the 10 pathotypes of BB pathogen compared to PAU 201, which shows resistance against nine pathotypes only. The mutant is being evaluated in multilocation replicated yield trials. Molecular analysis of the mutant RYT 3207 and PAU 201 to identify the diverse/mutated regions is under progress.

*The author is thankful to the rice research team (Rupinder Kaur, Jagjit Singh Lore, Jagdeep Singh Sandhu, Naveen Singh, Tajinder Singh Bharaj, Navjot Kaur, Renu Khanna, Kuldeep Singh and Darshan Singh Brar) of PAU, Ludhiana for the valuable support).