Creation and evaluation of the varietal-linear hybrids of onion in Kazakhstan

The experiments were conducted in 2015-2017 on the experimental fields of the Kazakh Research Institute of Potato and Vegetable Growing located on the northern slope of the Zailiysky Alatau, 40 km to the west of the city of Almaty, under irrigation conditions. The aim of the research was a comprehensive field assessment of selective onion samples with sterile cytoplasm from onion Galantum and their derivatives - varietal-linear hybrids obtained by pollination with domestic cultivars. Visual assessment, which was conducted on the background of natural disease infection, showed that 20 accessions of onions had a very weak susceptibility to peronosporosis (1-10% of leaves); 63 - weak susceptibility (11-25% of the leaves); 91 - average susceptibility (2650% of leaves); 118 - severe susceptibility (more than 51% of the leaves). As the results of the research showed, onion accessions differed significantly in terms of productivity: the gross yield varied from 13,3 to 83,6 t/ha, the commodity yields ranged from 10,6 to 78,3 t/ha, and the marketability ranged from 65,4 up to 98,8%. Yield level above 70 t/ha had breeding accessions with sterile cytoplasm from onion Galanthum: ON518, ON533, ON519 and ON516, amounting to 83,6; 75,3; 74,2 and 73,4 t/ha, respectively. Very high marketability of bulbs had breeding accessions ON171 - 98,8%, ON439 - 97,6% and ON158 - 96,8%. The value of storage losses varied depending on the genotype of the selected onion breeding material. The greatest physiological reduction in weight was observed in the accessions ON517 -32,1%, ON516 - 26,5%, ON533 - 24.2% and ON336 - 17,7%, and the lowest - in the accessions ON431 - 4,6%, ON486 - 4,0% and ON327 - 3,4%. The correlation analysis showed a weak relationship between the parameters of the onion yield and its storabilioty (R = -0,10-0,24). Storability was mainly due to the physiological reduction in weight (R = -0,59), bulb soft rot (R = -0,59) and bulb sprouting (R = -0,69).