alireza moghaddam khamseh; Saeed Sayfzadeh; Jahanfar Daneshian; Hamidreza Zakerin; alireza valadabadi
Abstract
In order to evaluate the planting date delay on phenological traits, yield components, grain yield, and linoleic and linolenic fatty acids of new sunflower hybrids, an experiment has been conducted as split plot in a randomized, completely block design, with four replicates at the field of oilseed section ...
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In order to evaluate the planting date delay on phenological traits, yield components, grain yield, and linoleic and linolenic fatty acids of new sunflower hybrids, an experiment has been conducted as split plot in a randomized, completely block design, with four replicates at the field of oilseed section of seed and plant Improvement during 2014-2016 growing season. The treatments include seven sunflower hybrids (Barzegar, Farrokh, Haysan 36, Qasem, Shams, Azargol, and Haysan 25) on three planting dates (15 days after harvest of autumn (wheat), July 1, July 15, and July 30, respectively). The experimental results show significant effects of planting date on all traits except number of seeds per head and linolenic acid at the level of 1% and on the percentage of oil and linoleic acid at the level of 5%. The studied hybrids are significantly different in all traits except linoleic and linolenic fatty acids. The latest experimental hybrids include Barzegar and Azargol hybrids and the earliest hybrid is Farrokh. The highest grain yield is obtained from the date of the first sowing at the rate of 2840 kg / ha and in the case of delayed sowing the yield is reduced to 41%.
Fariba Amini; Shiva Shariat zade; Mehri Askary
Abstract
To study the effects of 24-epibrassinolode on improving germination parameters and seedling growth of typical American eggplant under chilling stress, an experiment with four concentrations of 24-epibrassinolode (0, 0.5, 1 and 2 µM) in completely randomized design in factorial form with three replicates ...
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To study the effects of 24-epibrassinolode on improving germination parameters and seedling growth of typical American eggplant under chilling stress, an experiment with four concentrations of 24-epibrassinolode (0, 0.5, 1 and 2 µM) in completely randomized design in factorial form with three replicates were performed in plant physiology lab of Arak University at 1391. Eggplant seeds were soaked in different concentrations of 24-epibrassinolode for 48 h and then moved to plate. Three plates each containing 20 seeds were considered as replications for each treatment. After planting the seeds, plated were divided into two groups. One group was transferred to an incubator with 16/8 -hour light/dark photoperiod (25 ± 1°C temperatures) and other group exposed to 4°C temperature for 4 days then transferred to the incubator. The results showed that 24-epibrassinolid had a great effect on the germination parameters, length of root and shoot, fresh and dry weights of root and shoot in both control and stress conditions. The increase of lipid peroxidation and membrane penetration that observed in chilling stress, indicated a significant decrease in treatment with 24-epibrassinolide. 1 μM concentration was the most effective concentration than others. In plants under chilling stress and 1 μM of 24-epibrassinolide, lipid peroxidation and membrane penetration decreased 28.30 and 37.89 percent, respectively.
Shiva Bazl; Rouholah Karimi; Ahmad Ershadi; Alireza Shahbodaghlo; Mousa Rasouli
Abstract
Cold stress is one of the limiting factors in production of greenhouse vegetables. Chemicals offer useful approach to reduce low temperature-induced damages. This study was conducted to evaluate the effect of foliar application of methyl jasmonate (MeJA) at concentrations of 0 (control), 50, 100, 200 ...
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Cold stress is one of the limiting factors in production of greenhouse vegetables. Chemicals offer useful approach to reduce low temperature-induced damages. This study was conducted to evaluate the effect of foliar application of methyl jasmonate (MeJA) at concentrations of 0 (control), 50, 100, 200 µM) on electrolyte leakage (EL), relative water content (RWC), soluble carbohydrates, proline, chlorophyll content and chilling index of greenhouse- grown cucumber (Cucumis sativus L. cv ‘Negin’) in 4-6 leaf stage. MeJA was sprayed two times/day on cucumber seedling in a greenhouse of Bu-Ali Sina University, as a factorial based on completely randomized design with five replications per treatment, inlate- summer of 2013. Two days after spraying, seedlings were transferred from 25ºC to cold chamber and were subjected to chilling treatments of 15, 10 and 5 ºC for 4 hours. The EL of all plants increased with reducing the temperature. However, in MeJA-treated plants, especially in application of 200 µM, a lower leaf EL was observed. A clear increase in soluble carbohydrates and proline concentration was observed with decreasing temperature from 15 to 5ºC in all plants while in MeJA -treated seedlings, especially in application of 200 and 100µM, a greater amount of these osmolytes were observed in compared to control. Moreover, exogenous application of MeJA reduced RWC and visual damage of cold-stressed seedlings but increased chlorophyll content in compared to control plants. These changes correlated with the increment of cold tolerance in the cucumber plants. The results indicated that MeJA application especially at 200 µM, has the capacity to improve chilling tolerance of seedlings and can be used as a prophylactic tool to protect against chilling injury of cucumber cultivars in greenhouses
Ahmad Ershadi; Samira Taheri
Abstract
Frost in early spring is one of the limiting factors in the production of grape. Chemicals offer useful approach to reduce low temperature-induced damages. Different concentrations of salicylic acid including: 0 (control), 0.5, 1 and 2 mM were sprayed twice on 10 year-old ‘Bidaneh Sefid’ ...
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Frost in early spring is one of the limiting factors in the production of grape. Chemicals offer useful approach to reduce low temperature-induced damages. Different concentrations of salicylic acid including: 0 (control), 0.5, 1 and 2 mM were sprayed twice on 10 year-old ‘Bidaneh Sefid’ grape vines at full bloom stage and changes in leaf soluble carbohydrates, proline and protein levels were measured in the next day morning. Leaf and stem samples were subjected to low temperatures of 0, -2, -4 and -8°C while flower clusters were exposed to temperature of 0, -2 and -4°C for three hours. Salicylic acid at 0.5mM concentration resulted in the highest amounts of soluble carbohydrates while the maximum proline content was observed with 0.5 and 1mM concentrations. Salicylic acid at 2mM concentration caused a decrease in soluble protein level. Salicylic acid, low temperature and their interactions had a significant effect on electrolyte leakage of different tissues. Salicylic acid treatments led to a reduction in electrolyte leakage of stem, leaf and cluster samples, compared to control. It seems that salicylic acid minimizes the negative effects of low temperature with evidence of less membrane damage by up-regulating the accumulation of osmoregulants such as soluble carbohydrates and proline.
Hossein Afshari; Raheleh Zahedi; Tahereh Parvaneh; Masoud Zadehbagheri
Abstract
In order to study the effect of different concentrations of salicylic acid in two commercial apricotcultivars of Shahrood namely ‘Shahrood 41’ and ‘Jaffari’, under cold stress, a factorial experiment wasconducted in a randomized complete block design with three replications in ...
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In order to study the effect of different concentrations of salicylic acid in two commercial apricotcultivars of Shahrood namely ‘Shahrood 41’ and ‘Jaffari’, under cold stress, a factorial experiment wasconducted in a randomized complete block design with three replications in 2012 at the AgriculturalResearch Center of Shahrood city. The test had four factors including: SA with three levels (0.625, 0.125,0.25mM), three stages of phenological growth (dormancy, swelling and flowering) and four temperature(four, zero, -2 and -4 degree centigrade) and two apricot cultivars (‘Shahrood 41’ and ‘Jaffari’) andmeasured traits were proline and soluble sugars. ‘Jaffari’ cultivar had the highest amount of solublesugars at -4 degree centigrade in bud swelling stage and the maximum rate of proline belonged to0.25mM of SA in the same cultivar, -4 degree centigrade and bud swelling stage. Ion leakage at differenttemperatures and different phonological growth stages were significantly different at five percent level.‘Jaffari’ with lower ion leakage at -4 degree and higher proline content than ‘Shahrood 41’ had higherresistance to frost.