Showing 5 results for Chilling
S. Mohammad Reza Khani, V. Reza Saffari, Z. Pak Kish,
Volume 4, Issue 13 (1-2015)
Abstract
Valencia is one of the major orange cultivars which is grown in south of Iran. A great portion of annual fruits is usually cold stored for several months. This experiment was carried out to determine the effects of putrescine and methyl jasmonate on some of orange (Citrus sinensis) “Valencia” fruit characteristics. Fruits were treated with 0 (control), 2.5 and 5 millimoles of putrescine and 0 (control), 10 and 20 micromoles of methyl jasmonate and then stored at 5±1°C, 85-90% relative humidity for 4 months. Oranges treated with 5 millimoles of putrescine and10 micromoles of methyl jasmonate indicated significantly reduced chilling injuries and fruit weight loss compared to the control treatment. During storage, ascorbic acid, organic acids, total soluble solids of the treated and control fruits reduced, and pH increased though, putrescine and methyl jasmonate treatments led to decreases in the latter changes, relative to the control. In conclusion, fruits treated with 5 millimoles of putrescine showed the best appearance with the most controlling effect on chilling injury.
Y. Moradmand, M. Mobli, A. A. Ramin,
Volume 5, Issue 16 (9-2015)
Abstract
Among the chemicals that their effects on reducing chilling injury has recently been studied are salicylates and jasmonates. Therefore, in this study the effects of salicylic acid and methyl jasmonate on increasing the cold tolerance of bell pepper cv. Emily was examined. Experiment was done as a 7×2 factorial in the completely randomized design (CRD) with four replications. The first factor contained salicylic acid in three concentrations of 0.1, 0.5 and 1 mM and methyl jasmonate at the rates of 0.001, 0.01 and 0.1 mM plus control (distilled water) and the second factor involved application of hormone, spraying whole plant and soil drenching. Treatments were applied at 7-9 leaves stage. After application of hormones, plants moved to 0º C for 3 days and then returned back to greenhouse temperature. Three days later different attributes were measured. Results showed that except for soluble sugars and leaf proline, there was no significant differences between two methods of hormone application. For all traits, application of hormone showed significant effects but due to significant interactions between hormone and application method, the effect of hormone treatment depended on the method of application. Drenching 0.5 mM salicylic acid reduced chilling injury (necrotic lesions) and increased quantum efficiency of PSII (Fv/Fm), chlorophyll content, soluble sugars and leaf proline, compared to untreated plants, thus improved cold tolerance. Methyl jasmonate in the rate of 0.01 mM reduced chilling injury and increased Fv/Fm in comparison with control, but only when it was used as drench it increased concentrations of chlorophyll a and b and soluble sugars and cold tolerance compared to other two concentrations.
F. Saydpour, M. Sayyari,
Volume 6, Issue 21 (12-2016)
Abstract
Cucumber is a warm season crop that suffers from chilling injury at temperatures below 10°C. In recent years, jasmonates have been used for reduction of chilling injuries in plants. An experiment was, therefore, conducted to test whether methyl jasmonate (MeJA) application at various concentrations (0, 0.05, 0.1 and 0.15 mM) through seed soaking or foliar spray would protect cucumber seedlings, subjected to chilling stress. Results showed that MeJA application decreased chilling index, ion leakage, malondialdehyde content and hydrogen peroxide free radical and increased growth parameters, proline contents, chlorophylls contents and antioxidant activity. Although, seed soaking method provided better protection compared to foliar spray method, the highest cold tolerance was obtained with 0.15mM MeJA application in both application methods that caused low level of chilling index (1.67), malondialdehyde content (0.11 nm g-1 FW), hydrogen peroxide free radical (0.22 nm g-1 FW) and ion leakage (32.87%). In general, it may be concluded that MeJA could be used effectively to protect cucumber seedling from damaging effects of chilling stress at the early stages of growth.
R. Amoaghaei,
Volume 11, Issue 40 (7-2007)
Abstract
Ferula ovina Boiss. is one of grazing species whose seed germination faces certain problems. The dormancy characteristics of and optimum conditions for seed germination of this species have not been investigated so far. The present research was designed to investigate the effect of GA3 and moist chilling on seed germination of this plant. At first, a factorial the experiment in a completely randomized design with 6 replicates was performed to evaluate the factors: cold period in 0-3 °C (0,3,5,7,9 weeks), GA3 concentrations (0,500,1000 PPm) and time of GA3 (before cold, during cold, after cold). In the second experiment, the effect of cold duration and GA on T50 Ferula seed was investigated in 6 replications. The best treatment was moist chilling for 7 weeks at 3 C or 3 weeks of moist chilling together with soaking in 500 PPm GA3 solution for 12 h. These treatments significantly increased germination percentage and decreased the time of for germination by 50% (T50) compared to control. The addition of GA3, together with cold duration was more effective than its application before cold period, addition of GA3 after cold period, no further increase in germination occurred. Also increasing GA3 concentration (500 to 1000 PPm) did not have any significant effect on the percentage of germination and could not replace the total need for pre chilling. The results showed that Ferula ovina seeds display an endophysiological dormancy that can be released by GA3 and moist chilling treatment.
M Naseri, M Rezai, M Abasi, S Jam, H Hosseini, O Sabzevari,
Volume 12, Issue 46 (1-2009)
Abstract
Common kilka were chilled during 1, 2, 3, 4 and 5 days to determine the influence of such storage times of fish over the quality of the final canned product. For this propose, common factors for determination of fish quality (moisture, total lipid, free fatty acid, peroxide, thiobarbituric acid and fatty acid profile) were selected and compared with the formation of fluorescence compounds in fish tissue and filling media of canned kilka. In this work common indices showed higher oxidative and hydrolytic rancidity of canned samples compared to raw material but the trend of deterioration with the increase of chilled storage time was not well shown. However, filling media fluorescence compounds was significantly increased with the increase of chilled storage time and the decrease of fish primary quality (P< 0.05). According to the present results, fluorescence detection of interaction compounds can provide a good technique to assess quality differences in the final product as its relates to the quality of the raw material used.
