Romanyuk L. Features of variability of quantitative characters at soybean hybrids and their use in breeding of early matured varieties

Subject of inquiry - four hybrid F1-F4-hjhulations and six varieties used for their making. The aim of investigations was the discovery of features of the most important economic character variability in soybean hybrids, the improvement of methods of valuable genotype selections, the creation of valuable breeding material and the development of earlyripensng high-yielding cultivar. The research methods are generally accepted. The theoretical results and novelty consist in the discovery of detaills of the most important agronomic character variability in soybean F1-F4 - hybrids, the determination of their breeding value, the improvement of selection methods in hybrid populations, the development of new early-season high-producing variety Ustya. The practical importance of findings consists in the development of breeding practice recommendations which secured raising the efficiency of breeding work in the direction of development and assessments (when using a new index rate-growth index) of the new parental material as well in the creation of new promising breeding lines and new early-ripening Ustya variety put on the Registry of Plant Varieties of Ukraine. The cultivar is cultivated in main crops in the Polissia and Forest-Steppe as well can be used as a forecrop of winter crops in all the regions of Ukraine. It exeeds the national standards on earliness of ripening and on the yield level up to 4 hkg/ha. The sphere of applicathion - agricultural production.