Exploitation of induced variation for enhancing the biomass production in rice (Oryza sativa L.)

Abstract

A study was undertaken for screening the EMS induced mutants of N22 for identifying high biomass mutants. In a population of 10000 mutants, 280 mutants were selected phenotypically and forwarded in which dry matter production along with 18 other traits including days to fifty per cent flowering, plant height, number of tillers per plant, number of productive tillers per plant, efficient tillering percentage, flag leaf length, flag leaf width, panicle length, number of filled grains per panicle, number of chaffy grains per panicle, spikelet fertility, hundred grain weight, grain length, grain breadth, wet biomass, grain yield , harvest index and vein density were characterized, Physiological traits namely SPAD reading, photosynthetic rate, transpiration rate, stomatal conductance and Ci/Ca ratio were also recorded. A total of 58 per cent had higher grain yield than N22 while a total of 214 mutants recorded with high dry matter production than N22. In terms of physiological efficiency, genotypes with high vein density are associated with high biomass as in the case of any C4 plants. Wild type N22 has 50 minor veins and 8 major veins while 56 mutants possessed more than 50 minor veins and 10 major veins. Two mutants namely PL.No.36 and Pl.No.183 were found to be promising, which recorded high dry matter production with more number of minor veins, had high chlorophyll content and high photosynthetic rate.

Keywords

• mutation
• n22
• biomass
• vein density
• photosynthetic rate
• c1/ca ratio