The present study was conducted to evaluate the effects of partial root-zone drying （PRD） irrigation technique on stomatal conductance （gs）, leaf water potential （qJpd）, leaf relative water content （RWC）, vege...The present study was conducted to evaluate the effects of partial root-zone drying （PRD） irrigation technique on stomatal conductance （gs）, leaf water potential （qJpd）, leaf relative water content （RWC）, vegetative growth, fruit quality and enzymatic antioxidants of young plants of four Olea europaea L. varieties （Picholine Marocaine, Haouzia, Picholine Languedoc and Manzanilla） grown under arid conditions in Southern Morocco. In this irrigation strategy, a split-root technique was used to divide the root system of the plants in two parts. Two water regimes were used： （1） control, with both root compartments well watered; （2） PRD, with one compartment irrigated （50% of the control）, the other compartment was kept dry switching every 10 days. For all olive varieties studied, gs and the shoot length of the plants subjected to PRD decreased, whereas, Woo and RWC remained higher. The effect of PRD was similar among the four olive varieties, with their stomata closing in response to the water deficit before any significant changes in leaf water status were detectable. At the agronomic level, the benefits of PRD on olive were expressed by an earlier maturity and by higher values of olive fruit weight and dimensions, especially, in Manzanilla, which produced a fruit reaching 7.1 g and 2.6 cm, respectively. The enzymatic activities of soluble peroxidases （POX）, insoluble peroxidases （POXins）, polyphenoloxidase （PPO） and superoxide dismutase （SOD） were up-regulated under PRD. Picholine Marocaine and Haouzia showed higher enzymatic activities revealing that in these two varieties, PRD had possibly induced oxidative stress, which resulted in an up-regulation of the antioxidant activities of POXins, POX, PPO and SOD under water deficit.展开更多
文摘The present study was conducted to evaluate the effects of partial root-zone drying （PRD） irrigation technique on stomatal conductance （gs）, leaf water potential （qJpd）, leaf relative water content （RWC）, vegetative growth, fruit quality and enzymatic antioxidants of young plants of four Olea europaea L. varieties （Picholine Marocaine, Haouzia, Picholine Languedoc and Manzanilla） grown under arid conditions in Southern Morocco. In this irrigation strategy, a split-root technique was used to divide the root system of the plants in two parts. Two water regimes were used： （1） control, with both root compartments well watered; （2） PRD, with one compartment irrigated （50% of the control）, the other compartment was kept dry switching every 10 days. For all olive varieties studied, gs and the shoot length of the plants subjected to PRD decreased, whereas, Woo and RWC remained higher. The effect of PRD was similar among the four olive varieties, with their stomata closing in response to the water deficit before any significant changes in leaf water status were detectable. At the agronomic level, the benefits of PRD on olive were expressed by an earlier maturity and by higher values of olive fruit weight and dimensions, especially, in Manzanilla, which produced a fruit reaching 7.1 g and 2.6 cm, respectively. The enzymatic activities of soluble peroxidases （POX）, insoluble peroxidases （POXins）, polyphenoloxidase （PPO） and superoxide dismutase （SOD） were up-regulated under PRD. Picholine Marocaine and Haouzia showed higher enzymatic activities revealing that in these two varieties, PRD had possibly induced oxidative stress, which resulted in an up-regulation of the antioxidant activities of POXins, POX, PPO and SOD under water deficit.
