In viticulture, rootstocks are essential to cope with edaphic constraints. They can also be used to modulate scion growth and development to help improve berry yield and quality. The rootstock contribution to scion growth is not fully understood. Since nitrogen (N) is a significant driver of grapevine growth, rootstock properties associated with N uptake and transport may play a key role in the growth potential of grafted grapevines. We evaluated N uptake and transport in a potted system using two grapevines rootstocks [Riparia Gloire (RG) and 1103 Paulsen (1103P)] grafted to Pinot noir (Pommard clone) scion. Combining results of nitrate induction and steady-state experiments at two N availability levels, we observed different responses in the uptake and utilization of N between the two rootstocks. The low vigor rootstock (RG) exhibited greater nitrate uptake capacity and nitrate assimilation in roots after nitrate resupply than the more vigorous 1103P rootstock. This behavior may be attributed to a greater root carbohydrate status observed in RG for both experiments. However, 1103P demonstrated a higher N translocation rate to shoots regardless of N availability. These distinct rootstock behaviors resulted in significant differences in biomass allocation between roots and shoots under N-limited conditions, although the overall vine biomass was not different. Under sufficient N supply, differences between rootstocks decreased but 1103P stored more N in roots, which may benefit growth in subsequent growing seasons. Overall, greater transpiration of vines grafted to 1103P rootstock causing higher N translocation to shoots could partially explain its known growth-promoting effect to scions under low and high N availability, whereas the low vigor typically conferred to scions by RG may result from the combination of lower N translocation to shoots and a greater allocation of biomass toward roots when N is low.

在葡萄栽培中，砧木对于应对水土流失是必不可少的。它们还可用于调节接穗的生长和发育，以帮助提高浆果产量和品质。砧木对接穗生长的贡献尚不完全清楚。由于氮（N）是葡萄生长的重要驱动力，因此与氮吸收和运输相关的砧木特性可能在嫁接葡萄的生长潜力中发挥关键作用。我们使用嫁接到黑皮诺（Pommard克隆）接穗的两种葡萄砧木[Riparia Gloire（RG）和1103 Paulsen（1103P）]在盆栽系统中评估了氮素的吸收和运输。结合硝酸盐诱导和稳态试验在两个氮素有效水平下的结果，我们观察到两种砧木之间氮素吸收和利用的响应不同。与充满活力的1103P砧木相比，补充硝酸盐后低活力的砧木（RG）在根部表现出更大的硝酸盐吸收能力和硝酸盐同化作用。此行为可能归因于在两个实验中在RG中观察到的更高的根碳水化合物状态。然而，无论氮的有效性如何，1103P都显示出较高的氮素向芽的转运速率。在氮有限的条件下，这些不同的砧木行为导致了根与芽之间生物量分配的显着差异，尽管整个藤本植物的生物量没有差异。在充足的氮供应下，砧木之间的差异减少了，但1103P在根中存储了更多的氮，这可能有利于随后的生长季节的生长。总体，