Abelmasov O. Adaptation of source material, allied with plasma Iodent in selecting early-season hybrids of corn for steppe zone of Ukraine

The dissertation the features of manifestation of breeding signs of the source lines, sister hybrids and self-pollinated families of plasma Iodent are investigated. An estimation of the initial material on the basic economic-valuable features has been carried out. The best families of this plasma have been allocated for use in breeding work when creating high-yielding early- season maize hybrids. The correlation between productivity and other selection characteristics in the investigated material is determined. The results of estimation of outgoing lines, sister hybrids and self-pollinated families for resistance to growing conditions are presented. The general and specific combining ability of the source material and the self-pollinated S1-6 families created on their basis in relation to the basic economic indicators has been established. The best samples with high and stable over the years are the effects of GCA and SCA variants on the main selection criteria. For the economic evaluation of test-cross hybrids, the definition of the yield index was established for the ratio of grain yield to its harvest humidity. In the best test-cross hybrids, it ranged from 0,44 to 0,68 at it’s value in the standard hybrids of 0,34–0,45. The following hybrids of corn entered in the State Register of Plant Varieties have been proposed for growing in farms of all ownership forms of the Steppe and Forest-steppe zones: early-season: DB Lada (FAO 190), DN Patriot (FAO 190); middle-aged – DN Zoryana (FAO 210); DN Fiesta (FAO 260); middle – DN Julia (FAO 340), DK Burshtyn (FAO 350), DN Vesta (FAO 370). They provide an increase in grain yields of 3–5 % compared with the corresponding hybrid standards at a lower level by 1,2–2,3 % of the harvest moisture content.