Variation in outcrossing rate and genetic structure on six cultivars of Vicia faba L. as affected by geographic location and year

The present study was conducted to evaluate the importance of two environme ntal factors, year and geographic location, on the cultivar outcrossing rat e and genetic structure of Vicia faba L. under natural field conditions. Ou tcrossing rates were estimated for six cultivars using isozyme markers, the mixed mating model and the multilocus method. The genetic structure was de scribed by Wright's fixation index and the inbreeding equilibrium coefficie nt. Faba bean outcrossing rate, as measured by multilocus estimates was rel atively invariable among cultivars within locations. Our results suggest su bstantial variation in outcrossing rate associated with geographic location (Mediterranean subtropical and temperate climates enhancing the cross-poll ination). Year variation was far less important than geographic variation.