Concentration of dominant fertility genes-restorers in populations of o. p. large-seeded sunflower varieties

Seven OP sunflower varieties for restoring ability of pollen fertility in progenies from crossing with CMS on the base of Нelianthus petiolaris were studied. Borodinsky, Lakomka and Krepysh OP varieties had 20.4; 19.5 and 18.6 % fertile plants in F1, respectively in spite of SPK, Oreshek and Kulundinsky 1 had only 1.5; 2.4 and 2.6 % of such plants. As a result of reproduction OP variety Krepysh during 2000-2006 the percentage of plants with restoring ability was decreasing from 51.1 to 18.6 %. For this reason it is necessary to use such character as additional one for OP varieties structure control during reproduction process.