In vitro embryo rescue plant regeneration and genetic transformation studies in grapevine

Abstract

Grape is an important commercial fruit crop worldwide, owing to its wide adaptability under temperate, sub-tropical and tropical climatic conditions. Taxonomically, grapes are divided into two sub-genera, Euvitis Planch. (2n=38) and Muscadinia Planch. (2n=40) (Einset and Pratt, 1975). Most commercial cultivars of grape belong to Vitis vinifera. In the year 2005, the world production of grapes was to the tune of 66 million tonnes. In India, grape is grown on an area of 60,000 ha with a production of about 1.6 million tonnes (FAO STAT, 2005), which comprises mainly of table grapes. Thompson Seedless and Flame Seedless (V. vinifera L.), developed at Davis, California, USA are two important commercial table grape varieties in the world. Though the pinnacle of fruit quality, most commercial table grape varieties lack resistance to biotic and abiotic stresses. Though seedlessness is one of the most important marketable traits of table grapes, it limits the use of these varieties for grape improvement programmes by conventional methods because these can only be used as male parents with seeded varieties as female parents. In contrast to conventional breeding methods, biotechnological approaches like in ovulo embryo rescue and genetic transformation have opened new vistas in grapevine breeding and offer attractive alternatives to supplement ongoing research efforts of developing cultivars with enhanced characteristics. By using a suitable plant regeneration system, Agrobacterium tumefaciens-mediated plant transformation offers the potential to introduce foreign DNA into the existing genome to obtain plantlets with specific traits, which have been difficult, particularly in V. vinifera.