THE CHANGE OF SOLUBLE CARBOHYDRATES IN PEACH LEAVES DURING WILTING

During drought, plants face water deficit, which leads to changes in their physiological processes. One of the main changes is a decrease in the accumulation of soluble sugars during photosynthesis. The aim of the study was to investigate the resistance of peach leaves to wilting conditions and the effect of moisture loss on the amount of soluble sugars in them. Peach leaves of ‘Dzhaminat’ and ‘Dagestansky Zolotoy’ cultivars bred in Dagestan served as an object of study. Water-holding capacity was determined according to the method of A.I. Lishchuk. The content of soluble sugars on the background of changes in the water regime of leaves was studied by paper chromatography. Total water content in leaves of two cultivars amounted to 69.2 % (‘Dzhaminat’) and 58.6 % (‘Dagestansky Zolotoy’). The total water content in leaves of ‘Dzhaminat’ cv. was 11 % higher than that of ‘Dagestansky Zolotoy’ cv. In the process of wilting after 2 hours, moisture loss by its leaves amounted to 3.5 %, which is 3.8 % less than in the leaves of ‘Dagestansky Zolotoy’ cv. (7.0 %). The minimum moisture loss during wilting for 4 hours was also observed in ‘Dzhaminat’ cv. (7.6 %), which is 5.3 % higher than that in ‘Dagestansky Zolotoy’ cv. (12.5 %). The maximum value of recovery of leaf water content was observed in variety ‘Dzhaminat’ сv. (96 %), which is 18 % higher than in ‘Dagestansky Zolotoy’ cv. (78 %). Leaf sucrose content in ‘Dzhaminat’ cv. before wilting was 47.4 % higher than that in ‘Dagestansky Zolotoy’ cv. With prolonged wilting (4 hours) sucrose content increased by 17.2 % (‘Dzhaminat’) and 64 % (‘Dagestansky’). As for the glucose content, there is a decrease in this indicator with prolonged wilting (4 hours) by 13 % (‘Dzhaminat’) and 30.8 % (‘Dagestansky Zolotoy’). The fructose content also increases with longer wilting compared to the control by 18 % (‘Dzhaminat’) and 42 % (‘Dagestansky Zolotoy’). The leaves of ‘Dzhaminat’ cv. accumulate glucose by 19.8 % and fructose by 10.3 % more than those of ‘Dagestansky Zolotoy’ cv. The leaves of ‘Dzhaminat’ cv. stand out with a high degree of resistance to wilting; the total content of soluble sugars in the leaves of this cultivar increases with wilting; sucrose and fructose increase quantitatively, and glucose decreases; ‘Dzhaminat’ cv. is the most resistant to the stress factor and is promising in terms of sugar accumulation and content.