In vitro plant regeneration and genetic transformation studies in grapevine: Crimson Seedless

Abstract

Grape is the second most widely grown fruit crops of the world. It is grown under varied climatic conditions ranging from temperate to semi tropic and tropics. It is a woody perennial, cultivated in 90 countries, covering an area of about 19 million acres with Europe having the largest share (60%). Taxonomically, grapes are divided into two subgenera, Euvitis Planch. (2n=38) and Muscadinia Planch. (2n=40). Vitis vinifera belongs to the sub-genera Euvitis. The genus Vitis is broadly distributed between 25° and 50° N latitude in eastern Asia, Europe, the Middle East and North America. According to an estimate, 65.5 million tons of grapes were produced world over with a value of 144 billion pounds (FAO, 2005). In India, grape is grown on an area of 60,000 ha with a production of about 1.6 million tonnes (FAO, 2005), which comprises mainly of table grapes. Crimson Seedless, a red, table grape variety was developed by Ramming and Tarailo of the USDA, Fresno, California, USA as a result of cross between Emperor and C33-199 (Dokoozlian et al., 1998). It is mostly grown in California and has recently been introduced in India. The variety is favored due to its good shelf life and excellent eating characteristics like crisp and firm berries. Like most of the seedless cultivars of grapes world over, Crimson Seedless too is susceptible to various fungal diseases like mildews, anthracnose, fruit rot etc. Genetic improvement of seedless grapevine through conventional breeding is a cumbersome and time taking process. By employing appropriate regeneration system and Agrobacterium-mediated plant transformation method, it is possible to introduce foreign DNA into the existing genome to obtain plants with improved disease resistance (Kikkert et al., 2000).