Growth and Fruit Quality of ‘Kyoho’ Grapevines Grafted on Autotetraploid Rootstocks

Abstract

The growth of ‘Kyoho’ (Vitis × labruscana Bailey × V. vinifera L.) grapevines grafted on colchicine-induced autotetraploids of two grape rootstocks, ‘Riparia Gloire de Montpellier’ (‘Gloire’, V. riparia Michx.), and ‘Couderc 3309’ (‘3309’, V. riparia × V. rupestris), was compared with the original diploids. Micro-propagated rootstock and ‘Kyoho’ grapevines were grafted in vitro and rooted. During the rooting and acclimating stage, ‘Kyoho’ grapevines grafted on tetraploids had much shorter shoots and internodes than those grafted on the counterpart diploids. In the nursery period in pots, ‘Kyoho’ grapevines grafted on each tetraploid rootstock also showed weaker growth than those grafted on the corresponding diploid rootstock. After planting in the vineyard, lateral shoot growth after primary shoot-tipping, the trunk cross-sectional area and pruned cane weight of ‘Kyoho’ grapevines grafted on each tetraploid rootstock were also smaller than those grafted on the corresponding diploid rootstock. The berries of ‘Kyoho’ grapevines grafted on tetraploids showed much deeper skin coloration than those of vines grafted on diploid rootstocks.