Ecological and Genetic Features of Protein Content Control in Spring Barley Varieties in the Conditions of the Northern Steppe of Ukraine

The results of the application of the chlorophyll fluorescence and proline content (PC) methods for assessing the drought tolerance of oilseed radish varieties are presented. The interval of Relative humidity of soil (RHS) 60.8% - 35.6% with raising air temperature (0.8°C day-1) and decrease leaf RWC (6.7% day-1) was investigated. An increase F0 and Fst of 1.11 and 0.42 relative fluorescence units (RFU) per 1% decrease in RHS, 2.33 and 0.88 RFU per 1°C increase in air temperature, and 0.35 and 0.13 RFU per 1% decrease in leaf RWC was showed. A decrease Fpl, Fm at 6.57 and 50.1 RFU per 1% decrease RHS, 13.8 and 105.2 RFU per 1°C increase temperature and 2.1 and 15.7 RFU per 1% decrease leaf RWC was determined. An increase PC of 0.20 and 0.07 nmol gDW-1 per RFU increase F0 and Fst and 1.14 and 8.73 nmol gDW-1 per RFU decrease Fpl and Fm was noted. An increase PC of 5.74 nmol gDW-1 per 1% decrease in RHS and 12.05 nmol gDW-1 per 1°C increase in air temperature was proved.