Distant hybridization in grapes through embryo rescue for desirable traits- A review

Abstract

Grape is the one of the most important fruit crop grown all over the world. Wide-hybridization is an important tool in the hands of the plant breeder and a cytogeneticist. It is the first step to transfer genes of the wild species into the cultivated ones. Distant Hybridization involves parents belong to the different species of the same genus (Interspecific hybridization) or of different genera (Intergeneric hybridization). In order to introgress desired traits viz., seedlessness, triploidy, into genotypes having other important attributes, viz., stress-resistance (biotic and abiotic stresses). Hybridization between distantly related Vitissp is often used by breeders. Breeding efficiency of hybridization between distantly related species is low, mainly due to differences in chromosome numbers between different subgenera, which often lead to cross incompatibility and embryo abortion. However, this problem can be addressed by in ovulo embryo rescue and the technique has been extensively applied to rescue inherently weak, immature or hybrid embryos to breed seedless and triploid grapes for the hybridization of distantly related Vitis sp. It is likely that the breeding of seedless grapes will still be a major application in the future and more cultivars of different Vitis sp. such as V. rotundifolia, V. labrusca and wild Chinese Vitis sp. (V. amurensis, V yenshanensis, V quinlingenesis, V hancockii, V romanetti), which are resistant to various biotic and abiotic stresses, are still encouraged to be used as male parents in hybridizations with V. vinifera cultivars in order to obtain stress resistant and high quality seedless grapes. In present review of literaturean effort has been made with an objective to understand how the combination of distant hybridization with the help of embryo rescue technique together will be a promising approach to breed novel seedless grape cultivars.