Effects of water deficit on olive trees cv. Chemlali under field conditions in arid region in Tunisia

Effect of Water Deficit Imposed during the Early Developmental Phase on Photosynthesis of Cocoa (<i>Theobroma cacao</i> L.)

“…Plant heights ranged from 69.9 cm for F 3 Amason watered 3-day interval at 50% field capacity to 10.2 cm for Amelonado watered 7-day interval at 25% field capacity ( Table 2). Differences in the leaf area ranged from 252.3 cm 2 for T 1 watered daily at 50% field capacity to 99.0 cm 2 for Amelonado watered 7-day interval at 25% field capacity ( Table 3).…”

“…Such variations are mostly due to adjustments in their morphological parameters like leaf area, number and thickness of leaves as well as other features that are generated by phylogeny and adaptations [2]. Aside its morphological adjustment, several studies have shown that plant tolerance or sensitivity to water stress depends on their physiological characteristics [3]. Many physicological mechanisms displayed by plants across different agro-ecological zones are not only related to environmental parameters but also genetic dependant [4].…”

Anatomical adaptations of Astragalus gombiformis Pomel. under drought stress

“…Therefore, the maintenance of appropriate plant water status during water deficit is essential for continued growth and this process can be achieved by stomatal regulation [8]. Thus, stomatal closure significantly decreases transpiration rate and so, contributes to maintaining positive turgor pressure of the cells [9].…”

“…Leaf tissues exposed to drought shows various responses. Thus, in many species such as, Ctenanthe setosa and Triticum aestivum, the entire lamina and mesophyll thickness were reduced under drought stress [2][3][4][5][6][7][8][9][10][11][12][13][14], while it was unaffected by water stress in salvia spendens and Glycine max [13][14][15][16]. Bussotti et al [17] found that limited soil moisture caused a major thickening of the mesophyll, especially in the leaf cuticle and spongy parenchyma of the beech plant, Fagus sylvatica.…”

“…Multiple characteristics of vascular structure have been investigated, such as modifications of the vascular bundle number and area and alteration of xylem/ phloem ratio, which are thought to be involved in the resistance of the plant to environmental stresses [18]. Several studies have shown that xylem and/or phloem vessel diameter was reduced in Ctenanthe setosa and Triticum aestivum plants subjected to drought stress [2][3][4][5][6][7][8][9][10][11][12][13][14]. Thus, xylem with narrow vessels is physiologically better protected against cavitation [19].…”