VARIETY-SPECIFIC FEATURES OF BARLEY AT DIFFERENT STAGES OF ONTOGENESIS

In modern technologies of growing grain crops, high priority is given to the choice of varieties with significant adaptive potential and the development of ways to increase the resistance of plants to the action of various stresses. The purpose of our research was to identify the specific features of different varieties of barley during critical periods of growth. The studies were carried out in 2020–2021. The objects of research were varieties of spring barley created in the Moscow Research Institute of Agriculture. A series of laboratory and vegetative experiments were conducted, in the course of which we studied the indicators of the physiological status and varietal specificity of the resistance of spring barley to oxidative stress induced by an osmotically active sucrose solution during de-etiolation (laboratory experiments) and caused by soil drought at the VI stage of organogenesis (vegetative experiment, varieties ‘Vladimir’ and ‘Raushan’). The biometric indicators of sprouts and indicators of water status were evaluated. In all experiments, the varieties responded to stress by increasing the content of the oxidative stress marker malondialdehyde (MDA). Weak resistance of vegetative organs was noted in 1) roots – variety ‘Raushan’ (3.8 under stress conditions vs. 0.92 μM/g of raw mass under optimal conditions). ‘Moskovsky 2’ (8.1 vs.2.0), ‘Elf’ (4.5 vs. 1.38); 2) sprouts – ‘Raushan’ (4.6 vs.1.54), ‘Elf’ (5.0 vs. 1.37), ‘Nur’ (6.0 vs. 2.4). Varieties ‘Moskovsky 86’ and ‘Vladimir’ were the most resistant to stress since the accumulation of MDA increased to a lesser extent compared to its base content (‘Moskovsky 86’ – sprouts: 5.5 vs. 2.8; roots: 3.0 vs. 2.2 μM/g of raw mass; ‘Vladimir’ – sprouts: 3.4 vs. 2.9; roots: 3.9 vs.3.2 μM/g). Moreover, the content of chlorophylls a, b and carotenoids in varieties ‘Moskovsky 86’ and ‘Vladimir’ decreased respectively by 5.1; 5,9; 6.7 % and 8.0; 17,4; 6.9 % compared to the control options. Thus, variety ‘Vladimir’ is more stress-resistant than the other ones.