Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, via Archirafi 20, 90123, Palermo, Italy.
Institute of Biosciences and BioResources, National Research Council, Corso Calatafimi 414, 90129, Palermo, Italy.
Plant Physiol Biochem. 2020 Mar;148:282-290. doi: 10.1016/j.plaphy.2020.01.025. Epub 2020 Jan 21.
We investigated the response of two Sicilian grapevine cultivars, Catarratto and Nero d'Avola, to potassium deficiency and drought stress. Two-year-old plants grafted on 1103 Paulsen were grown in agriperlite, with or without potassium in the fertigation solution for six weeks, and subjected to moderate drought stress by suspending irrigation for one week. Potassium content of leaves, roots and xylem sap were measured with an ion-selective electrode. Changes in stomatal conductance, stem and leaf water potential and hydraulic conductance were compared between genotypes and treatments. Potassium deficiency led to significant decreases in leaf potassium content in both cultivars and under both well-watered and drought stress conditions. Potassium content in xylem sap showed no significant differences between cultivars and was correlated with stem hydraulic conductance, particularly in the drought stress treatments. Under drought stress conditions, potassium availability led to an increase in stomatal conductance, particularly in Nero d'Avola. Both cultivars showed a rather isohydric behavior under these experimental conditions, and the level of isohydry varied with potassium availability. These results can be useful for the development of optimal fertigation practices and the selection of drought tolerant varieties.
我们研究了两个西西里岛葡萄品种，卡塔拉托（Catarratto）和黑珍珠（Nero d'Avola），对低钾和干旱胁迫的响应。两年生的植株嫁接到 1103 保罗森砧木上，在农业珍珠岩中生长，灌溉液中含有或不含有钾，持续 6 周，然后通过暂停灌溉 1 周来施加中度干旱胁迫。用离子选择性电极测量叶片、根系和木质部汁液中的钾含量。在基因型和处理之间比较了气孔导度、茎和叶片水势以及水力导度的变化。低钾导致两个品种在充分浇水和干旱胁迫条件下叶片钾含量显著降低。木质部汁液中的钾含量在品种之间没有显著差异，与茎水力导度相关，特别是在干旱胁迫处理中。在干旱胁迫条件下，钾的可用性导致气孔导度增加，特别是在黑珍珠中。在这些实验条件下，两个品种都表现出相当的等水行为，等水程度随钾的可用性而变化。这些结果可用于开发最佳的灌溉实践和选择耐旱品种。
