Gholamhasan Movahed; Nima Ahmadi; Ahmad Moieni
Abstract
In order to evaluate the responses of two ecotypes of Damask rose (Rosa damascena) to exogenous ethylene, an experiment was conducted based on a completely randomized design (CRD) at the laboratory of Postharvest Physiology, Tarbiat Modares University, Tehran, Iran. Damsk rose cut stems containg flower ...
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In order to evaluate the responses of two ecotypes of Damask rose (Rosa damascena) to exogenous ethylene, an experiment was conducted based on a completely randomized design (CRD) at the laboratory of Postharvest Physiology, Tarbiat Modares University, Tehran, Iran. Damsk rose cut stems containg flower buds and/or open flowers, single buds, or multiple flowers were exposed to exogenous ethylene for 24 h. Plant organs were placed into hearmatically seald glass chambers, where ethylen was injected, to achieve 0, 1, 2, 3, and 4 µl/l concentrations. Biocehmival characteristics, enzyme activities and morphological characteristics including flower life, contents of anthocyanin, flavonoide, and proline were determind in Kashan and Azaran ecotypes of Damask rose. The lowest psotharvest life was observed at 3 and 4 μl concentration of ethylene and the highest abscission was observed in Azaran ecotypes at a concentration of 4 μl/l of ethylene after four days. Anthocyanin and proline content and catalase activity reduced in both ecotypes studied. For both ecotypes, the lowest content of anthocyanin, proline and the lowest catalase activity (48/77 ΔA 240/mg protein) were observed in those treated with ethylene at 4 µl/l. The highest malondialdehyde (3.63 µmol/g petal fresh weight) was found in Azaran ecotype flowers treated with 4 µl/l ethylene concentration. Decrease of total protein in Kashan flowers (0.32 mg/g fresh petal) was much less than that in Azaran flowers (0.2 mg/g fresh petal). Based on these results, Kashan could be recommended as a tolerant ecotype to be used in breeding programs.
Mehri Mashayekhi; Fariborz Habibi; Mohamad Amiri
Abstract
Mechanisms of drought stress tolerance of GF677 rootstock, peach and almond hybrid, (Prunus persica × Prunus amygdalus) were studied under in vitro conditions. Plantlets of GF677 rootstock were subcultured into the Murashige and Skoog (MS) solid proliferation medium containing 1 mg/l BA (6-Benzyladenine) ...
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Mechanisms of drought stress tolerance of GF677 rootstock, peach and almond hybrid, (Prunus persica × Prunus amygdalus) were studied under in vitro conditions. Plantlets of GF677 rootstock were subcultured into the Murashige and Skoog (MS) solid proliferation medium containing 1 mg/l BA (6-Benzyladenine) and 0.1 mg/l NAA (naphthaline acetic acid) in four drought stress levels 0 (control), 10, 20 and 30 g/l polyethylene glycol 6000 (corresponding to osmotic potentials 0, -0.2, -0.4 and -0.6 Mpa, respectively). After six weeks results showed that induced drought stress had a significant effect on measured parameters. By increasing drought levels in the culture medium, antioxidant enzymes activity (catalase and peroxidase), total protein content and proline content significantly increased; meanwhile soluble sugars had non-significant increasing in the different levels of drought. According to the results it can be concluded that, the most important mechanisms of drought tolerance of GF677 rootstock under in vitro conditions are the use of antioxidant defense system, increasing protein synthesis (enhancing genes expression) and proline accumulation and osmoregulation by soluble sugars had less important.
Fariborz Habibi; Mohammad Esmaeil Amiri
Abstract
Enzymaticactivity and biochemical responsesof two citrus rootstocks [sour orange (Citrus aurantium L.) and trifoliate orange (Poncirus trifoliata Raf.)] to in vitro salinitystress were studied. Explants of both rootstocks were transferred to Murashige and Skoog (MS) solid proliferation medium containing ...
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Enzymaticactivity and biochemical responsesof two citrus rootstocks [sour orange (Citrus aurantium L.) and trifoliate orange (Poncirus trifoliata Raf.)] to in vitro salinitystress were studied. Explants of both rootstocks were transferred to Murashige and Skoog (MS) solid proliferation medium containing 8.9 µM Benzyladenine (BA) and 0.5 µM Naphthaline Acetic Acid (NAA) supplemented with 0, 50, 100, 150, 200 mM of sodium chloride (NaCl) with six replicates. After six weeks, results showed that, rootstock, salinity levels and their interaction, had a significant effect on all of the measured parameters. Antioxidant enzymes activity such as: catalase, peroxidase, ascorbate peroxidase, proline content, soluble sugars and malondialdehyde (MDA) content increased in both rootstocks by increasing salinity level. The amounts of increasing in sour orange rootstock were greater than trifoliate orange, except for peroxidase enzyme and MDA. Total protein content decreased by increasing salinity level in both rootstocks. Sour orange rootstock has higher total protein content than trifoliate orange. According to the results, sour orange rootstock was more tolerant to salt stress.