Abstract:

Sunflower (Helianthus annuus L.) is one of four main oil crops in the world and its hybrid production depends on three lines (sterile line, maintainer line and restoring line). That is why cytoplasmic male sterility (CMS) in sunflower is the research focus through years. The sterility mechanism of PET1, the single source of hybrid breeding of sunflower, is the occurrence of chimeric genes resulting from the intramolecular recombination in mitochondrial genome. As a result, the chimeric gene encoded a new polypeptide which impair the development of male gamete. The physiological mechanisms by which the products of these genes interfere with the formation of male gametophytes are still the subject of intense research. Variable germplasm of CMS would decrease the crisis of single source for hybrid production, and make lots of sense in ornamental sunflower as well.

Key words: Sunflower, CMS, mtDNA