Seedless grape breeding for disease resistance by using embryo rescue

Abstract

An efficient system of seedless grape breeding for disease resistance through embryo rescue was developed by using an interspecific hybrid 'Beichun' of V. vinifera × V. amurensis as the pollen donor. Genotype and medium were confirmed to play important roles in this system, when a combined culture phase of solid plus liquid was used. 'Emerald Seedless' showed the highest percentage of plant development (19.6 %) in EMERSHAD and RAMMING (1994) medium (ER) among the females, suggesting it is more sensitive to ovule culture. To further improve the breeding efficiency, different amino acids were tested by using ovules from 'Emerald Seedless' × 'Beichun'. The addition of asparagine, glycine, arginine and glutamine (2.0 mmol·l^-1 respectively) yielded a higher plant development rate than the basal medium. The best result was obtained from asparagine supplemented medium, with 55.0 % ovules generated plants. The field performance to downy mildew [Plasmopara viticola (Berk. and Curtis) Berl. and de Toni] and anthracnose [Elsinoë ampelina (de Bary) Shear] of the parents and progenies was also evaluated. Disease resistance in F1 generation demonstrates continuous variation, with some resistant progenies, accounted for 5.7 % from offsprings, beyond the range observed in the parents. No correlation was observed between the resistance to the two pathogens in this research.