Gamma Radiation as A Mutagenic Agent for Salinity Tolerance Improvement in Some Sweet Sorghum, (Sorghum bicolor L.) Genotypes

Document Type : Original Article

Authors

1 Department of Breeding and Genetics - Sugar Crops Research Institute-Agricultural Research Center, Giza, Egypt.

2 Agricultural Botany Department, Faculty of Agriculture Saba Basha, Alexandria University, Alexandria, Egypt.

3 Sugar Crops Research Institute - Agricultural Research Center, Giza, Egypt.

Abstract

Salinity is the most common abiotic stress against cultivated crops in the world. Therefore, there are several ways to find out a possible solution to this problem. Mutation breeding approach is one of these ways to elicit salinity tolerant varieties through the induction of beneficial mutations by applying mutagenic agents, either chemically or by radiation. The current study was conducted to apply gamma radiation as a mutagenic agent to induce genetic variation in sorghum plants which can produce different genotypes and give the opportunity to initiate some salinity tolerant genotypes. To proceed with such an experiment, the seeds of four genotypes of sweet sorghum namely., GK Ahron, Brands, Tracy, and Rex were grown under four salt concentrations (control, 3000, 4000, and 5000 ppm) after irradiation by 300 Gy of gamma rays compared with untreated ones at differentdevelopmental stages morphologically, biochemically, and by molecular genetic analysis. The results showed that the genotypes GK Ahron, Brands, and Rex had a positive response to salinity tolerance accompanied by improvement in some studied characteristics. Non-Radiated Tracy has died at a salt concentration of 5000 ppm. From the present investigation, it could be recognized that Rex a halophyte plant because of is tolerant to salinity and had the highest quality and yield assessments. On the other hand, Tracy was a glycophytic one that had the lowest ones. All of the examined parameters decreased with increasing salt concentrations, except for proline. Rex genotypewas the most responsive to radiation and salinity. The radiated genotypes and non-radiated genotypes have different banding patterns.Therefore, in this study, the possibility of creating beneficial salinity tolerance mutations on sweet sorghum crops occurred by using gamma rays as well as other crops which could be helpful in the salinity breeding program in sweet sorghum

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