Studies on the Fragmented Shoot Apex of Grapevine

Abstract

The hormonal and nutritional requirements for the culture of fragmented shoot apices of grapevine were examined. Benzyladenine at 10 μM added to the full strength Murashige and Skoog basal medium was found to be optimal for both the initial growth of apical fragments to individual leaves, and the subsequent capacity of these leaves to produce adventitious shoots. Serial sectioning of the site of shoot proliferation on the leaves revealed meristematic areas at the surface of the basal swellings with vascular connections to the underlying tissue. Using the same culture conditions, adventitious shoots could be induced from a range of grapevine cultivars incorporating several major Vitis species. Variations in the responses of the cultivars Cabernet Sauvignon and Sultana to the culture conditions are described. The growth habits of plantlets derived from fragmented shoot apices during culture and on subsequent transfer to the glasshouse are compared and discussed.