METHOD FOR SELECTION OF HIGH PERFORMANCE HEAT-AND DROUGHT-RESISTANT LINES OF PUMPKIN MACROCARPOUS

摘要

The method for selection of highly heat- and drought-tolerant lines of pumpkin macrocarpous plants includes laboratory evaluation of heat resistance in the early stages of ontogeny, and in the collection nursery the seeds are sowed, on the fifth day of the seedlings the length of cotyledons is measured, which is linked to plant productivity (correlation coefficient r = 0,53), in the flowering stage five developed leaves of each accessions are taken using a microscope eyepiece micrometer, with an increase in x15 and x40 eyepiece lens by counting the number of stomata on the underside of the leaf in the field of view of the microscope, determining the degree of heat resistance grade in the average number of stomata on the 5-9 points (correlation coefficient r = 0,74), simultaneously, during the flowering stage, using a pyrometer it is defined the upper leaf surface temperature of five plants at 12:00 hours of the day, by determining the degree of drought resistance that is associated with the temperature of the leaf, the lower the temperature of the leaf, the greater drought resistance (correlation coefficient r = 0,68), per totality of indicators of the heat resistance performance, drought resistance and productivity the elite plants are selected under field conditions.