THE DROUGHT EFFECT ON PRODUCTIVITY OF DIFFERENT SPRING BARLEY GENOTYPES

Drought stress is one of the most serious environmental stresses that occur in nature and is markedly reflected in the growth and development of plants. The main purpose was to quantify reactions of spring barley (Hordeum vulgare L.) to soil drought during flowering period and to identify differences among four genotypes that differ in their origin. Characteristics of water atributes like relative amount of water in plant (RWC), water, osmotic and pressure potentials were measured. We quantified drought influence on four genotypes of barley. Water potential as estimation of water status, is very useful for fixing water transport in the system soil-plant-atmosphere. Gradual dehydration of the original substrate in laboratory conditions led to a gradual loss of water (RWC) from assimilatory organs and loss of turgor, which ended in plant wilting. With the gradual dehydration decreased also osmotic and water potential and loss of turgor was observed as well. Limitation of physiological processes in the case of drought during flowering period, when mechanisms of automatic compensation are broken, is the cause for a decrease in the amount of grains. We analyzed differences among genotypes in harvest reduction with statistical tools.