Variability studies in rice ( Oryza sativa L.) using induced mutation

Abstract

Rice (Oryza sativa L. 2n=24) is the most important cereal crop cultivated widely in many parts of the world. Creation of genetic variability is the basic step in any crop improvement programme. Mutation breeding has been a controversial issue for many years. In recent times, many successful results have been reported and a number of mutants have been released as cultivars. The material consisted of rice variety PY-5 whose M2 generation was studied with four sets of well dried 200 seeds were selected for treating with ethyl methane sulfonate. The concentrations of the mutagens used for four sets were 0.2, 0.4, 0.6 and 0.8 percent. In M2 generation, the bulked seeds of Ml were sown treatment wise along with control (non-treated). In M2 generation, observations we taken for six important yield component characters viz., plant height, number of productive tillers per plant, length of the primary panicle, length of boot leaf, 100 grain weight and grain yield per plant. Statistical parameters like mean, variance, co-efficient of variation(CV), heritability and genetic advance as percent of mean were computed for all traits studied adopting the standard statistical method. In the current investigation, mean for different traits shifted both in the positive and negative directions due to mutagenic treatments. The mean value recorded the positive shift for characters such as length of boot leaf, number of productive tillers per plant, panicle length and grain yield per plant in M2 generation. Both positive and negative shift was found in plant height and 100 grain weight. In the present investigation, significant variation has been observed in the mutant populations for the traits, number of productive tillers per plant, panicle length and grain yield per plant. Mutants having significantly high number of productive tillers, panicle length and grain yield per plant were selected from the plants treated with 0.8 percent.