efficiency of different lettuce (lactuca sativa l.) emasculation methods for hybrid seed production

producing hybrid lettuce is prevented by flower structure and usually lead to selfing. based on it, this experiment was carried out to evaluate the performance of different physical and chemical emasculation methods for producing lettuce hybrid seed. a numbers of cultivars with dominant and recessive traits were used as male and female parents, respectively. in the first experiment, physical emasculation methods including washing, forceps and combination of them together with a control treatment were compared. in the second experiment, the effects of gibberellin concentrations of 50, 100, 200 ppm and control were evaluated. the results of analysis of variance in the first experiment showed that method of emasculation had significant effect on the percentage of produced hybrid seeds, while the effect of parent pollen was not significant. however, the mean comparison results showed no significant difference among emasculation treatments. in the second experiment, different concentrations of gibberellin had significant effects on the percentage of produced hybrid seeds and non-fertile pollens. the highest percentage of hybrid seeds (about 85 percent) and non-infertile pollens (about 80 percent) were obtained by using 200 ppm gibberellin.