Overcoming hybridization barriers in strictly cleistogamous Vicia ervilia (L.) Willd.

Bitter vetch, Vicia ervilia (L.) Willd., is an annual cleistogamous legume originally used for human consumption and over time replaced by other pulses and downgraded to a fodder crop. When coupled with a small degree of cross hybridization, cleistogamy confers evolutive plasticity to the plant species. We set up optimal conditions to overcome the existing cross hybridization barriers between different landraces of V. ervilia. Genotypes of Turkish origin were crossed with Italian counterparts characterized by high seed production. A cyto-histological analysis of flower development was undertaken to determine the optimal stage for emasculation and manual cross. Ninety-eight crosses were carried out and the hybrid nature of the putative F1 progenies was assessed by SSR DNA markers. Fifty-five seeds were obtained of which only five gave rise to hybrid plants. Among these, only three turned out to be fertile and two of which generated a consistent number of F2 seeds whose plants were assessed for seed production and plant growth habit. Most of the evaluated traits showed mean values of the F2 plants intermediate between the two initial parents.