Protocols for Micropropagation of Woody Trees and Fruits

CHAPTER 23
MICROGRAFTING IN GRAPEVINE (VITIS spp.)
M. MHATRE AND V.A. BAPAT
Nuclear Agriculture & Biotechnology Division, Bhabha Atomic Research Centre,
Trombay, Mumbai 400 085, India. E-mail: mmhatre@barc.gov.in
1. INTRODUCTION
Grapes are sought after fruit grown for its high nutritional quality and taste and its
use in the wine industry. Grapes are mainly cultivated in the temperate regions but
some cultivars that are tolerant to high temperatures have been introduced to tropical
and subtropical countries. Commercial production of grapes is approximately 60.9
metric tonnes (FAOSTAT, 2004). Over the past decade substantial increases in
grapevine plantings have been driven by increasing wine exports (Pathirana &
McKenzie, 2005). Amongst the genus Vitis, V. vinifera and its selections are the
commercially popular table varieties as well as used in wine making.
Most commercial plantations utilize direct planting of selected varieties. However,
cultivated varieties of grape are susceptible to microbes, mites, insects, nematodes
and more importantly to Phylloxera leading to decline in total crop productivity.
Therefore it is necessary that the planting material obtained for the establishment of
new vineyards must be free from diseases, especially viral. Since once a vineyard is
established, minimizing losses caused by viral infection is difficult to achieve (Martelli,
1993) numerous attempts have been made at generating resistant varieties but have
met with limited success. To overcome this, several methods have been developed to
index the disease status of vines such as, (a) serological (Monis & Bestwick, 1996),
(b) molecular (Goszczynski & Jooste, 2003), (c) woody grafting (Martelli et al., 1993)
and (d) immunosorbent electron microscopy, sequential poly-acrylamide gel electrophoresis
for viroids, dsRNA analysis and nucleic acid hybridization (Macquaire
et al., 1993; Martelli et al., 1993). During this period, the idea has emerged ‘to graft
fruit-bearing scions onto resistant rootstocks to get infection free vines’.
Conventionally, grapes are mainly propagated by cuttings, layering and grafting.
Sprouts that arise during vegetative propagation serve as the base material for further
clonal multiplication and propagation. In some grape varieties and some rootstocks,
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S.M. Jain and H. Häggman (eds.), Protocols for Micropropagation of Woody Trees and Fruits, 249–258.
© 2007 Springer.