Scalisi Alessio, Marino Giulia, Marra Francesco Paolo, Caruso Tiziano, Lo Bianco Riccardo
Department of Agricultural, Food and Forest Sciences (SAAF), University of Palermo, Palermo, Italy.
Agriculture Victoria, Department of Jobs, Precincts and Regions, Tatura, VIC, Australia.
Front Plant Sci. 2020 Mar 24;11:340. doi: 10.3389/fpls.2020.00340. eCollection 2020.
Sustainable irrigation is crucial to reduce water use and management costs in modern orchard systems. Continuous plant-based sensing is an innovative approach for the continuous monitoring of plant water status. Olive ( L.) genotypes can respond to drought using different leaf and fruit physiological and morphological mechanisms. This study aimed to identify whether fruit and leaf water dynamics of two different olive cultivars were differently affected by water deficit and their response to changes of midday stem water potential (Ψ), the most common indicator of plant water status. Plant water status indicators such as leaf stomatal conductance (g) and Ψ were measured in the Sicilian olive cultivars Nocellara del Belice (NB) and Olivo di Mandanici (MN), in stage II and III of fruit development. Fruit gauges and leaf patch clamp pressure probes were mounted on trees and their raw data were converted in relative rates of fruit diameter change (RR) and leaf pressure change (RR), sensitive indicators of tissue water exchanges. The analysis of diel, diurnal and nocturnal fluctuations of RR and RR highlighted differences, often opposite, between the two cultivars under water deficit. A combination of statistical parameters extrapolated from RR and RR diurnal and nocturnal curves were successfully used to obtain significant multiple linear models for the estimation of midday Ψ. Fruit and leaf water exchanges suggest that olive cultivar can either privilege fruit or leaf water status, with MN likely preserving leaf water status and NB increasing fruit tissue elasticity under severe water deficit. The results highlight the advantages of the integration of fruit and leaf water dynamics to estimate plant water status and the need for genotype-specific models in olive.
可持续灌溉对于降低现代果园系统的用水和管理成本至关重要。基于植物的连续传感是一种用于连续监测植物水分状况的创新方法。油橄榄（Olea europaea L.）基因型可通过不同的叶片和果实生理及形态机制对干旱作出响应。本研究旨在确定两种不同油橄榄品种的果实和叶片水分动态是否受到水分亏缺的不同影响，以及它们对午间茎水势（Ψ）变化的响应，午间茎水势是植物水分状况最常用的指标。在果实发育的第二和第三阶段，对西西里油橄榄品种贝利切诺切拉（NB）和曼达尼西油橄榄（MN）的叶片气孔导度（g）和Ψ等植物水分状况指标进行了测量。将果实测量仪和叶片膜片钳压力探头安装在树上，并将其原始数据转换为果实直径变化相对速率（RR）和叶片压力变化相对速率（RR），这是组织水分交换的敏感指标。对RR和RR的日变化、昼夜波动和夜间波动的分析突出了水分亏缺条件下两个品种之间的差异，这些差异往往相反。从RR和RR的昼夜及夜间曲线推断出的统计参数组合成功用于获得估算午间Ψ的显著多元线性模型。果实和叶片的水分交换表明，油橄榄品种可能优先考虑果实或叶片的水分状况，在严重水分亏缺条件下，MN可能保持叶片水分状况，而NB则增加果实组织弹性。结果突出了整合果实和叶片水分动态以估算植物水分状况的优势，以及在油橄榄中建立基因型特异性模型的必要性。
