EFFECTS OF GAMMA RADIATION ON GERMINATION AND PHYSIOLOGICAL PARAMETERS IN BREAD WHEAT (TRITICUM AESTIVUM L.) GENOTYPES

This research was carried out to determine the effects of gamma radiation on germination and physiological characteristics of bread wheat genotypes. Eight bread wheat genotypes were irradiated with 175, 200, 250 Gy gamma-ray. Physiological parameters were recorded in the M1 population for flag leaf area, days of heading, some stomata, chlorophyll content at three growth stages, and biomass (NDVI) at five growth stages. The results showed that flag leaf area (cm2), biomass (NDVI), chlorophyll content (SPAD) decreased with increasing gamma irradiation doses but days of heading increased. The data showed that in comparison with the control population germination in mutagen-treated population was less than over the control population. NDVI was taken in the control treatment and M1 mutant lines at five growth stages and NDVI in the mutagen treated population was less than over the control population. Flag leaf area varies widely as a consequence of its interaction with the genotypes of treatment factors. The highest flag leaf area was determined in the control treatment (21.85 cm2) and increasing in gamma irradiation level lowered flag leaf area (15.70 cm2) in M250 Gy gamma irradiation. Control treatment had higher chlorophyll content and an increase in the dose of gamma rays reduced the chlorophyll content of genotypes scaled at Z30, Z45, and Z55 growth stages. It can be seen that days of heading increased with an increasing dose of mutagen treatments. Days of heading in the control treatment were 145.12 days and 154.75 days in mutagen 250 Gy gamma dosses. Based on mean value genotypes BBVD7-2014 had a higher flag leaf area (22.98 cm2), followed by BBVD22-2016. The highest chlorophyll content was determined in BBVD22-2016 and Saban. Cultivars Anafarta and Abide had higher biomass (NDVI). In conclusion, gamma radiation could be useful for the alteration of physiological characters. Mutation breeding (gamma irradiation) is also a significant breeding tool that has been used successfully in several crops for breeding physiological and morphological traits.