Physiological and biochemical responses of young olive trees (Olea europaea L.) to water stress during flowering

Abstract

This study examines physiological and biochemical changes in three Moroccan varieties of young olive trees (Olea europaea L.) grown under three different water regimes (control, moderate stress and severe stress). Leaf relative water content (RWC), water potential (Ψw), transpiration rate (E), stomatal conductance (gs), maximum quantum efficiency of PSII (Fv/Fm), the contents of total chlorophyll (TCC), proline (ProC) and soluble sugars (SSC) were measured at the flowering stage during three growing seasons (2015, 2016 and 2017). ANOVA analyses showed that the effect of the water regime was predominant in all of the examined parameters, except for Fv/Fm, which was under the effect of both water regime and growing season. Impacts of variety and interactions were of lesser magnitude. Water deficit reduced E, Ψw and gs by 25%, while its effect on RWC and Fv/Fm was a decrease of about 7%; however, increases in SSC and ProC were more than 10%. Among the growing seasons, 2015 flowering displayed the lowest values for RWC, Ψw, E, gs, TCC and Fv/Fm, and the highest for ProC and SSC. Among plant varieties, no significant differences were observed. The three principal component (PC) axes accounted for 91% of total variance. PC1 was better explained by the water regime, while the growing season fitted PC3 variability. Correlation studies highlighted significant associations between most parameters. Positive relationships were found between RWC, Ψw, E, gs, Fv/Fm and TCC, while all of these parameters were negatively linked to ProC and SSC.

Role of Suillus placidus in Improving the Drought Tolerance of Masson Pine (Pinus massoniana Lamb.) Seedlings

“…Among them, RWC exhibited a negative relationship with proline, which was consistent with the results of Abboud et al [59]. This may relate to an adaptive mechanism to reduce water loss and preserve cell membrane integrity [82].…”

The opportunity of using durum wheat landraces to tolerate drought stress: screening morpho-physiological components

“…Under rising water shortages, plant species lose water mainly by transpiration and then they tend to control their stomatal closure. In addition, many studies showed that stomatal closure is a genotypic depending component ( Hajiboland et al ., 2015 ; Ahmad et al ., 2018 ; El et al ., 2019 ).…”

Genotypic and Environmental Variations in Kernel Color Indices in the Main Almond (Prunus dulcis (Mill.) D.A. Webb) Cultivars Grown in North-Eastern Morocco

“…PCA is a multivariate statistical analysis used with an emphasis on the reduction of variables that most explain data variability [45][46][47][48][49][50][51][52][53][54][55]. Indeed, several reports used the PCA approach in order to discriminate among cultivars, growing seasons, and growing areas based on physical fruit traits [12,22,56,57].…”