Disease-resistant grape hybrid development through embryo rescue techniques
摘要
Development of disease resistant grape hybrids is one of the primary objectives in viticulture industry to mitigate the yield losses due to fungal diseases. Embryo rescue is a promising technology which holds the potential in development of cultivars with enhanced disease resistance. Therefore, the study was designed to crossbreed different grape genotypes followed by utilization of embryo rescue to overcome post fertilization barriers and for successful development of hybrid plants. Conventional hybridization procedure was employed to crossbreed known disease resistant and susceptible genotypes. Results showed considerable variations among the cross combinations in response to embryo rescue. Two weeks after culturing, callus induction and organogenesis were observed in all cross combinations except for White Perlette × NARC Black and Flame Seedless × NARC Black. The regenerated plantlets were initially transplanted into pots containing peat moss and subsequently moved to green house for further growth. Among the regenerated plantlets, only the White Perlette × King’s Ruby and Flame Seedless × King’s Ruby crosses survived. To determine resistance of F1 hybrids to anthracnose and downy mildew, screening was done by artificial inoculation method as well as molecular markers linked to disease resistance. SCAR markers were used for screening against anthracnose while SSR markers linked to Rpv3 loci were used for screening against downy mildew. It was concluded from the results that among the hybrid plants developed through embryo rescue techniques, some exhibited resistance to anthracnose and downy mildew and showed reduced disease symptoms. These resistant plants carrying specific resistant alleles serve as a baseline for the future development of disease-resistant grapevine cultivars.