Vakulenko P. Productivity of sugar beet hybrids on sterile basis depending on the structure of the female component

The thesis deals with results of complex studies on breeding-genetic system of the use of CMS lines and single-cross hybrids as a female component of sugar beet hybrids on sterile basis. The influence of the structure of a female component on agronomic characteristics and productivity of hybrids on sterile basis and advantage of the use of single cross sterile hybrids as a female component over CMS lines were established. Single-cross hybrids were developed through hybridization of CMS lines of different origins with nonrelated maintainers. Biological features of single-cross hybrids were studied in comparison with CMS lines. Experimental hybrids on the basis of CMS lines and single-cross sterile hybrids were developed; they were compared as to their agronomical characteristics and productivity. On the basis of the results obtained for combining abilities of the components of experimental hybrids, the best six single-cross sterile hybrids were selected. New single-cross sterile hybrids CMS1 x Ot2, CMS5x Ot3 undergo ecological tests in the "Betaintercross" program. Key words: sugar beet, female component, CMS lines, sterility maintainer (O-type), single-cross sterile hybrids, experimental hybrids, combining ability