Some mechanisms of winter resistance in apricot flower buds in the period of ecodormancy
Laboratory of Molecular Genetic Selection of Fruit Crops, Federal State Budgetary Scientific Institution "Federal Agrarian Scientific Center of Agriculture of The South-East" (FSBSI "FASCA South-East". 7 Tulaikov Str., RU410010 Saratov, Russia
The accelerated development of flower buds during the thaw in apricots and almonds during the ecodormancy period leads to significant damage to the flower elements during return frosts and loss of future crops. The aim of the research was to identify the mechanisms of delay in the rate of development of flower buds during the ecodormancy period, their relationship with the degree of frost resistance and the timing of flowering in apricots. The following indicators of flower buds were analyzed: the degree of exit from endodormancy, frost resistance at temperatures of -18 °C and -31 °C, the degree of morphological development of flower elements, the activity of α-amylases at temperatures of +15 °C and + 60 °C, total content water, phenolcarboxylic acids, flavonoids and free proline. A significant positive correlation was revealed between the percentage of death of flower buds at a temperature of -18 °C and the percentage of buds emerging from endogenous dormancy (0.64*), the percentage of death of buds at a temperature of -31 °C and the degree of development of flower elements (0.70*), water content and the degree of development of flower elements (0.76**), amylase activity at +60 °C and amylase activity at +15 °C (0.76**), the content of phenolcarboxylic acids in the bark of shoots and flower buds (0.61*). For the first time, psychrophilic forms of α-amylases have been discovered in apricot flower buds.