Authors: Nilgün YENİCE, Orhan ARSLAN
Abstract: This research was carried out to determine the hybrid vigour (heterosis) with respect to yield and yield components between synthetic variety of sunflower (Helianthus annuus L.) and selfed lines forming this variety during the years 1993-1994 at the experimental field of the Field Crops Department of Faculty of Agriculture of Ankara University. In the first year, the synthetic variety was obtained by open-pollination from three broomrape resistant self-lines. In the second year, synthetic varitey, the mixture of the lines and control Vniimk-8931 and Ekiz 1 varieties were sown as randomized block desing with four replications in irrigated and non-irrigated experimental conditions. According to the results of the research, the hybrid vigour of synthetic variety in irrigated experiments was calculated as % 92.62 for oil yield, % 77.90 for seed yield, % 48.24 for diameter of seedless center of the head, %. 8.87 for per thousand seed weight, % -7.57 for husk percentage, % 5.51 for oil percentage and % -4.90 for stalk yield. Heterosis was not found for plant height and head diameter in this experiment. The hybrid vigour of syntetic variety in non-irrgated experiment was determined as; % 67.95 for oil yield, % 54.03 for seed yield, % 11.89 for plant height, % 11.49 for head diameter, % 7.79 for oil percentage %-6.16 for diameter of seedless center of the head, % 4.92 for stalk yield and % -4.80 for husk percentage. Heterosis was not found for weight per thousand seeds in non-irrigated experiment.