Heterosis and Inbreeding Estimates in Safflower¹

Estimates of heterosis and inbreeding depression in safflower ( Carthcmus tinctorius L.) were obtained for seven traits: flowering time, plant height, yield, seed weight, percentage of empty seeds, embryo percentage, and oil percentage. Selfed and single‐cross hybrid progenies were compared in two experiments, one involving five varieties and the other seven. In one experiment some of the hybrids were significantly superior to their best parents for height, yield, seed weight, and oil percentage. Inbreeding depression was observed only in about 10% of the cases. In a second experiment significant heterotic effects were observed for flowering time, height, seed weight, and oil percentage. Inbreeding depression was present in about 11% of the cases. Reciprocal effects were not generally significant, suggesting that cytoplasmic effects are not important in safflower.