Merli Maria Clara, Gatti Matteo, Galbignani Marco, Bernizzoni Fabio, Magnanini Eugenio, Poni Stefano
Istituto di Frutti-Viticoltura, Università Cattolica del Sacro Cuore, Via Emilia Parmense, 84 - 29122 Piacenza, Italy.
Funct Plant Biol. 2015 Feb;42(2):198-208. doi: 10.1071/FP14112.
Several recent papers have shown that in grapevine (Vitis vinifera L.), interpretation of responses to drought can differ depending upon the parameter chosen to express water use efficiency (WUE). In the present paper, a series of WUE expressions, including physiological and agronomical, were compared in potted grapevines (Vitis vinifera L. cv. Sangiovese) that were either well-watered (WW) or subjected to progressive drought before veraison (WS) by supplying decreasing fractions (i.e. 70%, 50% and 30% of daily vine transpiration (Trd) determined gravimetrically before vines were fully rewatered. Although single-leaf intrinsic and instantaneous WUE increased with water stress severity, seasonal and whole-canopy WUE were similar to that before stress, at 70% Trd and upon rewatering, but dropped during severe water stress. WUE calculated as mass of DW stored in annual biomass (leaves, canes and bunches) per litre of water used did not differ on a seasonal basis, whereas WS plants showed lower must soluble solids at harvest, and unchanged colour and phenolic concentration in spite of smaller berries with higher relative skin growth. Results confirm that whole-canopy WUE is a much better index than any single-leaf based WUE parameter for extrapolation to agronomic WUE and actual grape composition. In our specific case study, it can be recommended that water supply to drought-stressed Sangiovese grapevines before veraison should not be lower than 70% of daily vine water use.
最近的几篇论文表明，在葡萄（Vitis vinifera L.）中，对干旱反应的解读可能因选择用来表达水分利用效率（WUE）的参数而异。在本文中，对一系列包括生理和农艺方面的WUE表达方式进行了比较，这些表达方式来自盆栽葡萄（Vitis vinifera L. cv. Sangiovese），这些盆栽葡萄要么充分浇水（WW），要么在转色期前经历渐进性干旱（WS），通过供应逐渐减少的水分比例（即，在葡萄藤完全重新浇水前通过重量法测定的每日葡萄藤蒸腾量（Trd）的70%、50%和30%）。尽管单叶内在和瞬时WUE随着水分胁迫严重程度的增加而增加，但季节性和全冠层WUE在Trd为70%时以及重新浇水时与胁迫前相似，但在严重水分胁迫期间下降。以每升用水中存储在一年生生物量（叶片、茎和果串）中的干物质质量计算的WUE在季节基础上没有差异，而WS植株在收获时葡萄汁的可溶性固形物含量较低，尽管浆果较小但相对果皮生长较高，颜色和酚类物质浓度没有变化。结果证实，对于外推到农艺WUE和实际葡萄成分而言，全冠层WUE比任何基于单叶的WUE参数都是更好的指标。在我们的具体案例研究中，建议在转色期前对遭受干旱胁迫的桑娇维塞葡萄藤的供水量不应低于每日葡萄藤用水量的70%。
