Determination of Sugar Composition in Grapevine Rootstock Cuttings Used for Propagation

¹ Chemistry Department, Postgraduate Food Science Program, The University of Auckland, PB 92019, Auckland, New Zealand.

email: cj.oconnor{at}auckland.ac.nz

Rootstock cuttings used for propagation of grafted grapevines were sampled in two climatically different regions of New Zealand. The sugar profile of rootstock cuttings was determined during several months prior to grafting. Rootstock cuttings of the North American hybrid Vitis riparia x Vitis rupestris cv. 101-14 were taken from intact mother vines in a single vineyard from the Marlborough region and from three in Auckland. There was no significant difference in sugar content among rootstock cuttings from the Auckland vineyards. During the winter, sugar content of Marlborough cuttings was consistently higher than that of Auckland cuttings. A minimum sample size of five cuttings from each vineyard was validated using precision calculations. No significant difference in sugar content was found in tissues along the length of a single cane of an intact mother vine. Total sugar content of dormant cuttings was significantly lower when analyzed by HPLC than when using anthrone reagent.

Note:
Acknowledgments: We thank the University of Auckland Research Committee for grants toward purchase of instruments. We are indebted to J.A. Corban & Sons and nursery staff for supplying rootstock cuttings and for ongoing support. A.R. is grateful to the Auckland Branch, New Zealand Federation of Graduate Women and the New Zealand Foundation for Research, Science and Technology for financial support.

Key words: Vitis riparia x Vitis rupestris, sugar content, grapevine rootstock, precision graphs