Rossdeutsch Landry, Schreiner R Paul, Skinkis Patricia A, Deluc Laurent
Department of Horticulture, Oregon Wine Research Institute, Oregon State University, Corvallis, OR, United States.
USDA-ARS Horticulture Crops Research Unit, Corvallis, OR, United States.
Front Plant Sci. 2021 Jan 18;11:608813. doi: 10.3389/fpls.2020.608813. eCollection 2020.
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，砧木对于应对土壤限制至关重要。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未完全了解。由于氮（N）是葡萄生长的重要驱动因素，与氮吸收和运输相关的砧木特性可能在嫁接葡萄树的生长潜力中起关键作用。我们在盆栽系统中评估了两种葡萄砧木[河岸光辉（RG）和1103保尔森（1103P）]嫁接到黑皮诺（波马尔克隆）接穗上时的氮吸收和运输情况。结合两个氮有效性水平下的硝酸盐诱导和稳态实验结果，我们观察到两种砧木在氮的吸收和利用方面存在不同反应。低活力砧木（RG）在硝酸盐再供应后，根部的硝酸盐吸收能力和硝酸盐同化能力比活力更强的1103P砧木更大。这种行为可能归因于在两个实验中RG砧木中观察到的更高的根部碳水化合物状态。然而，无论氮有效性如何，1103P砧木向地上部的氮转运速率更高。这些不同的砧木行为导致在氮限制条件下根和地上部之间的生物量分配存在显著差异，尽管葡萄树的总体生物量没有差异。在充足的氮供应下，砧木之间的差异减小，但1103P砧木在根部储存了更多的氮，这可能有利于后续生长季节的生长。总体而言，嫁接到1103P砧木上的葡萄树蒸腾作用更强，导致向地上部的氮转运更高，这可以部分解释其在低氮和高氮有效性条件下对接穗已知的促生长作用，而RG砧木通常赋予接穗的低活力可能是由于向地上部的氮转运较低以及在氮含量低时生物量更多地分配到根部共同作用的结果。
