Evaluation of salt resistance mechanisms of grapevine hybrid rootstocks

The problem of soil salinization is increasing critically in China. The widespread rootstock Beta (V. labrusca×V. riparia) is relatively weak (Du et al., 2015), and the commonly used phylloxera-resistance rootstocks were still unable to satisfy the needs of production as well. F1 hybrids A15 and A17 of V. amurensis Rupr. cv. Zuoshan-1×SO4 (V. berlandieri×V. riparia) had strong salt tolerance were irrigated with 100 mmol·L−1 NaCl to explore the salt resistance mechanisms, the male parent SO4 was used as reference. The result showed that root activity was higher under salinity conditions in A15 and A17, with a more complete chloroplast structure investigated than that of SO4 under the NaCl treatment. Na+ accumulations in leaves and the whole plant of A15 and A17 were lower than SO4, whereas the Na+ retention capacity in roots were higher than SO4. The total amount of Na+ and K+ of roots and aboveground portion of grafted plants A15/SO4, SO4/A15, A17/SO4, and SO4/A17 further confirmed that stronger root Na+ retention capacity and upward transport of K+ of A15 and A17 under NaCl treatment. The non-invasive micro-test technology (NMT) manifested that A15 and A17 had a higher Na+ exclusion ability and a better root K+ retention ability; salt stress significantly up-regulated the relative expression of VvNHXP and VvHKT family genes in roots of A15 and A17.