Correlation between heterosis and genetic distance based on SSR markers in sunflower (Helianthus annuus L.)

Abstract

The objective of this study was to determine the correlation between SSR based genetic distance (GD) of new NS sunflower inbred lines and heterosis for six agronomic traits. Twenty three sunflower inbred lines (20 restorer lines and three female lines used as testers) and their hybrids were examined for plant height, head diameter, thousand seed mass, oil content, seed yield per plant and oil yield per plant. Significant heterosis was observed in hybrid combinations for all examined traits except oil content. Genetic distance between pairs of tested sunflower inbred lines ranged from 0.13 to 0.8. There was no significant positive correlation between genetic distance and mid- and better-parent heterosis, specific combining ability and mean value in any of the examined traits for all 60 hybrids. A highly significant negative correlation was found between GD and mean oil percentage (r=-0.33 p lt 0.01). Although GD was generally a poor predictor of heterosis, better results are obtained if hybrid combinations for each tester and each trait are analyzed separately.

Cilj rada je utvrdjivanje odnosa između genetske udaljenosti (GD) koja je određena SSR markerima (mikrosatelitima) kod novih inbred linija suncokreta i heterozisa za šest agronomskih svojstava. Ispitano je dvadeset tri inbred linije (dvadeset restorer linija i tri tester linije majki) i njihovi F1 hibridi za sledeća svojstva: visina biljke, prečnik glave, masa 1000 semena, sadržaj ulja u semenu, prinos semena i ulja po biljci. Zapažen je značajan heterozis kod hibridnih kombinacija za sva ispitivana svojstva sem za sadržaj ulja. Genetska udaljenost između parova ispitivanih inbred linija je bila od 0,13 do 0,8. Između genetske udaljenosti i heterozisa, posebnih kombinacionih sposobnosti i srednjih vrednosti svih ispitivanih svojstava, nije bilo značajne pozitivne korelacije. Jedina značajna vrednost, ali negativna, bila je u odnosu srednje vrednosti ulja i genetske udaljenosti (r=- 0.33 p lt 0.01). Iako se genetskom udaljenosti slabo može predvideti heterozis, bolji će se rezultati dobiti ako se analiziraju hibridne kombinacije za svaki tester i svako svojstvo pojedinačno.