Medrano Hipólito, Escalona José M, Cifre Josep, Bota Josefina, Flexas Jaume
Laboratori de Fisiologia Vegetal, Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa, Km 7.5, 07071 Palma de Mallorca, Balears, Spain.
Laboratori de Fisiologia Vegetal, Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa, Km 7.5, 07071 Palma de Mallorca, Balears, Spain. Corresponding author; email:
Funct Plant Biol. 2003 Jul;30(6):607-619. doi: 10.1071/FP02110.
The effects of moderate irrigation, compared with non-irrigation, on leaf photosynthesis and transpiration, grape yield, and quality parameters, were studied over ten years in two Spanish cultivars (Tempranillo and Manto Negro) of field-grown grapevines (Vitis vinifera L.). The aim was to increase our knowledge of the relationships between water availability, canopy water losses, photosynthesis, and fruit yield and quality. A second aim was to analyse some of the mechanisms of photosynthetic down-regulation under drought, such as the capacity for RuBP regeneration and Rubisco activity.Moderate irrigation improved plant water status, leaf photosynthesis and transpiration. Considering the results over ten years, soil water availability (estimated as pre-dawn leaf water potential, Ψ) largely determined leaf photosynthesis and leaf transpiration. Decreased photosynthesis was due to both stomatal and non-stomatal factors. The latter were related to decayed electron transport rate and reduced RuBP regeneration capacity, but not to decreased Rubisco activity.Moderate irrigation also improved grape yield, although this effect was much larger in Tempranillo than in Manto Negro. Moreover, the correlation between photosynthesis and grape yield was significant in Tempranillo, but not in Manto Negro. In contrast, the correlation between Ψ and several parameters reflecting fruit quality (such as soluble solids and total polyphenol content) was significant only in Manto Negro. These results suggest that there is a close link between water availability and grape yield, mostly through water stress effects on photosynthesis. Drought effects on grape quality are linked to water availability but not to photosynthesis or yield.
在西班牙两个田间种植的葡萄品种（丹魄和黑曼多）上，研究了适度灌溉（与不灌溉相比）对叶片光合作用和蒸腾作用、葡萄产量及品质参数的影响，为期十年。目的是增进我们对水分供应、冠层水分损失、光合作用以及果实产量和品质之间关系的了解。另一个目的是分析干旱条件下光合下调的一些机制，如核酮糖-1,5-二磷酸（RuBP）再生能力和核酮糖-1,5-二磷酸羧化酶（Rubisco）活性。适度灌溉改善了植株水分状况、叶片光合作用和蒸腾作用。综合十年的研究结果，土壤水分供应（以黎明前叶片水势Ψ估算）在很大程度上决定了叶片光合作用和蒸腾作用。光合作用下降是由气孔和非气孔因素共同导致的。后者与电子传递速率衰减和RuBP再生能力降低有关，但与Rubisco活性降低无关。适度灌溉还提高了葡萄产量，不过这种效果在丹魄品种上比在黑曼多品种上更为显著。此外，光合作用与葡萄产量之间的相关性在丹魄品种中显著，但在黑曼多品种中不显著。相反，Ψ与几个反映果实品质的参数（如可溶性固形物和总多酚含量）之间的相关性仅在黑曼多品种中显著。这些结果表明，水分供应与葡萄产量之间存在紧密联系，主要是通过水分胁迫对光合作用的影响。干旱对葡萄品质的影响与水分供应有关，但与光合作用或产量无关。
