Влияние осмотического стресса на прорастание семян Helianthus annuus L.: сахароза как осмотический регулятор

Abstract

Orenburg region belongs to the zone of risky agriculture, which is characterized by droughts alternating with dry and hot winds. Helianthus annuus L., variety ‘Poseidon 625’ is an important food crop cultivated in the region, therefore it is important to identify the influence of climatic drought already at the earliest stages of its ontogenesis. The aim of this study is to investigate the effect of different concentrations of osmotic substance (sucrose) on the germination and further growth of seedlings of H. annuus ‘Poseidon 625’. The laboratory germination was carried out in a vegetative chamber according to GOST 12038–84. The method of N.N. Kozhushko recommended by FRC VIR was used for evaluation of seed germination in physiological drought conditions. There are six variants of experiments on germination of seeds in sucrose solutions with concentrations of 1.4% (P = 1 atm), 4.4% (P = 3 atm), 7.4% (P = 5 atm), 10.5% (P = 8 atm), and 16.6% (P = 12 atm) and distilled water as a control. The study showed that the effect of osmotic pressure equal to 1 atm has no significant effect on germination, but has an early stress effect on seeds, reducing their germination energy even in conditions of minimal soil moisture deficiency. By means of a dispersion analysis, a significant decrease (p <<0.05) in both germination and growth processes of seedlings of H. annuus ‘Poseidon 625’ was found with increasing concentration of the osmotic solution by variants of the experiment. Thus, according to the reaction to the lack of moisture in the early stages of ontogenesis the studied variety can be assigned to the group of medium drought resistant.