UTILIZATION OF GAMMA RAYS TO INDUCE PROMISING RICE (Oryza sativa L.) MUTANTS

doi:10.12816/ejpb.2022.291743

UTILIZATION OF GAMMA RAYS TO INDUCE PROMISING RICE (Oryza sativa L.) MUTANTS

Document Type : Original research

10.12816/ejpb.2022.291743

Abstract

This experiment was conducted at Rice Research and Training Center, Sakha, Kafr Elsheikh, Egypt in 2019, 2020 and 2021 seasons. Six late mature rice genotypes with high yield and excellent grain quality were used. The seeds were treated in 2019 season with three doses of gamma rays (250, 300 and 350 Gy) to study the effect of gamma radiation on morphological, yield and its components and select new promising mutants. The obtained results revealed highly significant variations among studied genotypes due to treatments by the three doses of gamma rays. The hard effect of gamma rays occurred by 350 Gy dose. The earlier genotype was GZ10789-2 for 350 Gy in M3 generation and had the longest panicle in M2 with a dose of 300 Gy. The shortest plant recorded in M3 with 350 Gy for mutant Sakha 108-m, while Sakha Super 300 showed the highest values for panicle weight, panicles plant^-1 and grain yield plant^-1 on M2 with 250 Gy and recorded high seed set % in M3. The highest 100-grain weight was recorded in M1 with 250 Gy for the mutant GZ10789-1. The mutants Sakha Super 300-m and GZ10789-2 were the best new genotypes in M3, which performed short duration and semi-dwarf with keeping high yield potential. High positive correlation coefficient was found between grain yield plant^-1and days to heading, number of panicles plant^-1, panicle weight and 100-grain weight for untreated genotypes with values of 0.347, 0.419, 0.446 and 0.694, respectively. For the mutant genotypes, high positive correlation coefficients were recorded also between grain yield plant^-1 and each of panicle length, panicle weight and plant height with values of 0.652, 0.412 and 0.446, respectively. From presented results related to correlation, we can report that the mutation breeding could break the common correlation between traits, for example the relation between the yield and days to heading which turned from positive correlation under control to negative correlation after the mutated generations using 350 GY dose of gamma rays.

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