Physiological-biochemical characteristics of diploid and triploid varieties Malus domestika L., differ in ploidy level

The aim of this work was to study the comparative characteristics of physiological and biochemical activity of apple cultivars differing in ploidy based on gibberellic acid, the intensity of processes of lipid peroxidation, activity of components of the antioxidant system, protein-carbohydrate complex and respiration. Objects of study were the group of diploid and triploid apple varieties of All-Russian Research Institute of Horticulture breeding. According to the research results, triploid apple varieties in comparison with diploids have a sufficiently high level of metabolic processes. In the group of triploid varieties on the background of significant content gibberellic acid 15.23-33.74 g/g vs 8.57-of 18.78 mg/g of diploids, in the bark of shoots, the activity of amylases increased by 31.85% and high sugar content of 3.54-5.12% compared with the diploid varieties - 2.96-4.48% are determined. In addition, triploids have more intense level of respiratory 0.77-1.21 ml СО2/g·h compared to diploid varieties - 0.64-0.77 ml СО2/g·h, and activation of redox processes. In the group of triploid varieties in the bark of annual shoots high activity of superoxide dismutase (SOD) 103.35-139.40 c.u. and peroxidase - 1.20-2.69 c.u., against 75.46-125.65 c.u. and 0.95-2.04 c.u., accordingly, the diploids was observed. Triploid apple cultivars were characterized by malondialdehyde (MDA) content increased by 54%, which may be associated with increased level of oxygen active forms formation due to the high intensity of respiration and activity of SOD. Determination of free proline does not reveal differences between the study groups. However, the determination of total protein showed that the group of triploid apple varieties were characterized by high content in the bark of total protein of 4.70 to 6.20 mg/g vs of 3.70-4.00 mg/g of diploids. The comparative analysis showed that triploid apple varieties in comparison with diploids have sufficiently high level of metabolic processes.