mohammad delaviz; hosein sadeghi; mansour Taghvaee
Volume 23, Issue 3 , January 2017, , Pages 578-592
Abstract
The present study was conducted to evaluate drought stress and subsequent recovery on growth and biochemical changes of three Atriplex species. The study was performed as factorial based on completely randomize design with six replicates. The treatments included three Atriplex species (A. lentiformis, ...
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The present study was conducted to evaluate drought stress and subsequent recovery on growth and biochemical changes of three Atriplex species. The study was performed as factorial based on completely randomize design with six replicates. The treatments included three Atriplex species (A. lentiformis, A. leucocalada and A. canescence) and four irrigation regimes (100 as control, 75% FC as light stress, 50% FC as severe drought, and no irrigation). The results showed that light and severe drought caused a significant reduction in growth of all three Atriplex species, and no irrigation treatment caused the loss of A. leucocalada and A. canescence. The recovery could offset the loss partly in all three species, especially A. lentiformis, so that there were no significant differences between control and 75% FC treatments. Tissue moisture percentage showed no significant difference in control, 75, and 50% FC. In A. lentiformis, no irrigation treatment caused a significant reduction in moisture percentage; however, recovery offset a considerable part of this loss. Water deficit treatments (75 and 50% FC) increased the activity of catalase, peroxidase and superoxide dismutase. The highest activity of all four enzymes was obtained in A. lentiformis. Generally, drought stress, depending on stress levels, reduced the growth and increased the antioxidant enzymes in all three-study species, and recovery, depending on species and stress levels, could offset a part of this loss. A. lentiformis showed the highest drought resistance and higher recovery ability, which might be due to the higher activity of antioxidant enzymes.
Zahra Soleimannejad; Ahmad Abdolzadeh; Hamid Reza Sadeghi Pour
Volume 21, Issue 1 , June 2014, , Pages 83-94
Abstract
Puccinellia distans is a perennial, salt tolerant forage species that belongs to Poaceae family. The main objective of the present study was to evaluate the effect of different levels of salinity ongrowth, antioxidant enzymes activity and mineral accumulationin Puccinellia distans. The experiment was ...
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Puccinellia distans is a perennial, salt tolerant forage species that belongs to Poaceae family. The main objective of the present study was to evaluate the effect of different levels of salinity ongrowth, antioxidant enzymes activity and mineral accumulationin Puccinellia distans. The experiment was conducted based on a completely randomized design with five replications in green house. Salinity levels included 0, 100 and 200 mM NaCl. Plants were harvested before reproductive stage. The results indicated that salinity imposed significant reduction in growth of plants including shoot and total length, fresh and dry weight, leaf number and relative water content. Concentration of Na+ decreased and concentration of K+ and K+/Na+ ratio increased due to salinity in both shoots and roots. The activity of catalase and polyphenol oxidase decreased in shoots of plants treated with 200 mM NaCl compared to control, however, the activity of catalase, cell wall and soluble peroxidase, and polyphenol oxidase in roots and cell wall peroxidase in shoots of plants indicated significant increase due to the same salt treatment. Salt treatments led to increase of chlorophyll a, total chlorophyll and carotenoids contents and the amount of hydrogen peroxide. However, no significant change was observed in the amount of lipid peroxidation in roots and shoots. The results indicated that in spite of growth retardation and Na+ accumulation, salt treatments did not induce oxidative stress in Puccienellia distans. The reduction of K+ concentration, K+/Na+ ratio and relative water content may cause decrease of plant growth.