Among all fruit crops of horticultural importance, grapevines (Vitis vinifera L.) stand out as the most drought tolerant crop species whose tolerance is credited to their proficiency to recover from water stress in bo...Among all fruit crops of horticultural importance, grapevines (Vitis vinifera L.) stand out as the most drought tolerant crop species whose tolerance is credited to their proficiency to recover from water stress in both the natural and vineyard growing conditions. However, information on the recovery responses is relatively scant. Studies were conducted to address this issue using potted vines of the grapevine cultivar, Cabernet Sauvignon, which was subjected to water stress and along with anatomical and ultrastructural characterizations, physiological status was assessed in healthy and water stressed vines, and following recovery via rewatering from the water stressed vines. Water stress induced wilting of leaves, drooping of tendrils, and desiccation followed by abscission of shoot tip leaving behind a brown scar at the shoot apex. The wilted leaves accumulated ABA, which correspondingly reduced stomatal conductance and leaf water potential. Upon re-watering, both these parameters made a recovery with values similar to healthy leaves. Likewise, leaf anatomical features following rewatering resembled to that of healthy leaves. In clusters, water stress caused shriveling of preveraison (unripened) berries, which regained full turgor following water resupply, whereas the postveraison (ripening) berries in the same cluster remained unaffected as evidenced by the presence of viable mesocarp cells and epicuticular wax in the form of platelets. The study revealed that shoot tip with leaf primordia was most sensitive to water stress followed by fully expanded leaves and preveraison berries, whereas the postveraison berries remained unaffected. This information could be valuable to implementing irrigation strategies towards sustaining grape production in existing vineyards experiencing episodic droughts and targeted areas prone to drought.展开更多
Mineral nutrition is essential to growth and development of various plant organs including fruits;consequently deficiency of any element leads to a myriad of physiological disorders, which in fruits are manifested as ...Mineral nutrition is essential to growth and development of various plant organs including fruits;consequently deficiency of any element leads to a myriad of physiological disorders, which in fruits are manifested as ripening anomalies. In this study, nutritional composition in tandem with vascular structure of healthy grape clusters and clusters afflicted with SOUR shrivel, a ripening disorder has been examined to unravel its mechanistic basis. The healthy berries without any affliction accumulated the highest amounts of all nutrients, which paralleled with functional xylem and phloem tissues in their cluster framework. Among the macro nutrients, K occurred as the dominant element followed by P, Ca, Mg and S whereas B was the predominant micro nutrient followed by Fe, Cu, and Zn. Although, the SOUR shrivel berries and the healthy appearing berries of afflicted clusters followed similar accumulation patterns, their amounts were significantly lower than the perfectly healthy berries without any SOUR shrivel. The low nutrient levels of SOUR shrivel berries corresponded to necrosis of phloem tissues and a red discoloration of xylem tissues in their cluster framework indicating that a lack of functional vascular tissues provoked the induction of SOUR shrivel by reducing influx of xylem and phloem mobile nutrients into the afflicted berries. Hence, periodic nutritional checks starting before veraison may aid in curbing the incidence of SOUR shriveling.展开更多
文摘Among all fruit crops of horticultural importance, grapevines (Vitis vinifera L.) stand out as the most drought tolerant crop species whose tolerance is credited to their proficiency to recover from water stress in both the natural and vineyard growing conditions. However, information on the recovery responses is relatively scant. Studies were conducted to address this issue using potted vines of the grapevine cultivar, Cabernet Sauvignon, which was subjected to water stress and along with anatomical and ultrastructural characterizations, physiological status was assessed in healthy and water stressed vines, and following recovery via rewatering from the water stressed vines. Water stress induced wilting of leaves, drooping of tendrils, and desiccation followed by abscission of shoot tip leaving behind a brown scar at the shoot apex. The wilted leaves accumulated ABA, which correspondingly reduced stomatal conductance and leaf water potential. Upon re-watering, both these parameters made a recovery with values similar to healthy leaves. Likewise, leaf anatomical features following rewatering resembled to that of healthy leaves. In clusters, water stress caused shriveling of preveraison (unripened) berries, which regained full turgor following water resupply, whereas the postveraison (ripening) berries in the same cluster remained unaffected as evidenced by the presence of viable mesocarp cells and epicuticular wax in the form of platelets. The study revealed that shoot tip with leaf primordia was most sensitive to water stress followed by fully expanded leaves and preveraison berries, whereas the postveraison berries remained unaffected. This information could be valuable to implementing irrigation strategies towards sustaining grape production in existing vineyards experiencing episodic droughts and targeted areas prone to drought.
文摘Mineral nutrition is essential to growth and development of various plant organs including fruits;consequently deficiency of any element leads to a myriad of physiological disorders, which in fruits are manifested as ripening anomalies. In this study, nutritional composition in tandem with vascular structure of healthy grape clusters and clusters afflicted with SOUR shrivel, a ripening disorder has been examined to unravel its mechanistic basis. The healthy berries without any affliction accumulated the highest amounts of all nutrients, which paralleled with functional xylem and phloem tissues in their cluster framework. Among the macro nutrients, K occurred as the dominant element followed by P, Ca, Mg and S whereas B was the predominant micro nutrient followed by Fe, Cu, and Zn. Although, the SOUR shrivel berries and the healthy appearing berries of afflicted clusters followed similar accumulation patterns, their amounts were significantly lower than the perfectly healthy berries without any SOUR shrivel. The low nutrient levels of SOUR shrivel berries corresponded to necrosis of phloem tissues and a red discoloration of xylem tissues in their cluster framework indicating that a lack of functional vascular tissues provoked the induction of SOUR shrivel by reducing influx of xylem and phloem mobile nutrients into the afflicted berries. Hence, periodic nutritional checks starting before veraison may aid in curbing the incidence of SOUR shriveling.
