Rootstock regulation of scion phenotypes: the relationship between rootstock parentage and petiole mineral concentration
Rootstocks not only provide tolerance to Phylloxera, but also ensure the supply of water and mineral nutrients to the whole plant. Rootstocks are an important way of adapting to environmental conditions while conserving the typical features of scion varieties. We can exploit the large diversity of rootstocks used worldwide to aid this adaptation. The aim of this study was to characterise rootstock regulation of scion mineral status and its relation with scion development.
Vitis vinifera cvs. Cabernet-Sauvignon, Pinot noir, Syrah, and Ugni blanc were grafted onto 55 different rootstock genotypes and planted as three replicates of five plants in sandy gravelly soil near Bordeaux, France (GreffAdapt plot). In 2020 and 2021, petiolar concentrations of 13 mineral elements were determined at veraison. Winter pruning weight, vigour, leaf chlorophyll content, fertility and yield were measured. Mg deficiency severity was visually scored for each plant. Rootstocks were grouped according to their parentage when at least 50 % of a Vitis species was present in order to determine whether the petiole mineral composition could be related to the genetic parentage.
Scion, rootstock, and their interactions had a significant influence on petiole mineral content and explained the same proportion of phenotypic variance for most mineral elements. Rootstock effect explained from 8 % for Al to 42 % for S of the variance and an important part for Mg with 35 %. The genetic background V. riparia increased the probability of low P and Mg contents. The differences in mineral status conferred by rootstocks were not significantly correlated with vigour or fertility.
This unique experimental design has shown that the rootstock effect is higher than the scion effect on the petiole concentration of most mineral elements. The evaluation of Mg levels by petiole analysis and intensities of deficiency symptoms showed, for the first time, the variability of the thresholds of satisfactory mineral nutrition. Therefore, fertilization management has to take the rootstock into account.
Issue: ICGWS 2023
1 EGFV, University of Bordeaux, Bordeaux Sciences Agro, INRAE, ISVV
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Vitis, climate change, plant material, mineral status, genetic background, rootstock x scion interaction