Osmotic stress resistance of different sorghum species affected by NaСl

Introduction. One of the most urgent issue of plant production which attracts the attention of many researchers and farmers, is salt tolerance of plants. Salinity has a negative effect, caused by the disruption of an osmotic balance of a cell that negatively affects water regime of plants. At the same time, plants experience growth inhibition and reduce their yield.The purpose of the study was to estimate resistance of different sorghum species to chloride salinity and to identify the most resistant genotypes.Methods. The study was carried out in the laboratory for plant physiology in 2018–2021. For the current study there has been carries out a modelling of a salt stress by a pure salt solution (concentration of 13 atm.) according to a conventional methodology, the control was distilled water.Results. There has been established the salinity stress effect on seed germination of different sorghum species. The values of germination energy and laboratory germination of grain sorghum were 53.1% and 62.0%; of sweet sorghum — 39.1% and 43.1; the values of Sudan grass — 30.1 and 33.5%, respectively. In the first and second groups — of highly resistant and resistant species (seed germination affected by salinity ranged from 61 to 100%) — were are 61% of grain sorghum genotypes, 56% of sugar sorghum genotypes and 6% of Sudan grass genotypes. There has been established a resistance degree and identified some features of the development of varieties with different degrees of resistance to this stress (length of sprouts and primary roots). Grain sorghum was found less susceptible to salinity stress of all studied species. Among grain sorghum samples, 9 genotypes have demonstrated the highest salinity resistance with a germination rate from 87.5 (Uch. 22/20) to 95.9% (Uch. 29/20). The maximum values were shown by the samples of Uch. 29/20 (95.95%), Uch. 20/20 (93.9%), Uch. 21/20 (93.8%), Jetta x Uch. 45/20 (91.5%) and Uch. 7/20 (90.8%), which indicated the ability to tolerate severe salinity concentration. 