ٍٍEbrahim Alami; Mahnaz Karimi
Abstract
One of the important objectives during the production cycle of ornamental plants is to regulate and control their growth. Hence, application of some plant growth regulators such as uniconazole (UN) and cycocel (CCC) is considered as an efficient method for reaching to this objective. To investigation ...
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One of the important objectives during the production cycle of ornamental plants is to regulate and control their growth. Hence, application of some plant growth regulators such as uniconazole (UN) and cycocel (CCC) is considered as an efficient method for reaching to this objective. To investigation the effect of uniconazole and cycocel on some morphological and biochemical characteristics of zinnia, a factorial experiment was conducted in a completely randomized design with five replications. Application of UN (0, 5 and 10 mg L-1) and CCC (0, 1000 and 1500 mg L-1) as growth retardants, was considered as the first and their application method (leaf spraying and soil application) was considered as the second factor. The effect of growth retardants on plant height, Time of flowering, peroxidase activity, endogenous gibberellins and leaf area were significant. The lowest plant height was observed in soil application of 10 mg L-1 UN. The tallest plant was observed in the control treatment. Growth retardants had significant effects on endogenous gibberellins and leaf chlorophyll contents. Highest activity of peroxidase enzyme was detected in plants treated by 10 mg L-1 UN. The highest and lowest numbers of leaves (21.6 and 16.4 leaves, respectively) were counted in control and 5 mg L-1 UN, respectively. According to the obtained results, the use of growth retardants is recommended to reduce the height and improve the qualitative and quantitative characteristics of zinnia flower.
Soheila Mohammadrezakhani; Zahra Pakkish
Abstract
Storage of Lime (Citrus aurantifolia L.) fruits, originally a tropical fruits, in low temperature confronts with several difficulties due to the risk of chilling injury (CI). To develop an effective method aiming to reduce CI, the effects of treatments containing 0, 0.5 and 1 Mg/lit brassinosteroids ...
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Storage of Lime (Citrus aurantifolia L.) fruits, originally a tropical fruits, in low temperature confronts with several difficulties due to the risk of chilling injury (CI). To develop an effective method aiming to reduce CI, the effects of treatments containing 0, 0.5 and 1 Mg/lit brassinosteroids (BRs) and hot water (HW) including 20°C as control, 45 and 55°C for 30 minute on CI was studied. Moreover lipid peroxidaion, hydrogen peroxide, catalase (CAT) and peroxidase (POD) activities were investigated in lime fruits stored at 1°C for 21 days. The CI, lipid peroxidaion, hydrogen peroxide were significantly reduced by BRs treatment particularly at 1Mg/lit and 45°CHW treatment. Furthermore fruits treated with 1Mg/lit BRs and 45 °C HW treatment exhibited significantly higher CAT and POD activities in comparison with the control fruits. These results suggest that BRs and HW treatment protect lime fruits from CI by enhancing antioxidant enzymes such as POD and CAT activities, and reduce lipid peroxidaion, hydrogen peroxide contents, and maintaining membrane integrity.
Negin Akhlaghi Amiri; Ali Asadi Kangarshahi; Kazem Arzani; Mohsen Barzegar
Abstract
Summer fruit drop (June drop) is one of the main reasons for low yield in some citrus varieties in northern Iran. Recognition of physiological changes in fruit abscission zone (calyx) and application of suitable treatments would reduce or control abscission. Hence, the changes of auxin, cellulose, and ...
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Summer fruit drop (June drop) is one of the main reasons for low yield in some citrus varieties in northern Iran. Recognition of physiological changes in fruit abscission zone (calyx) and application of suitable treatments would reduce or control abscission. Hence, the changes of auxin, cellulose, and polygalacturonase in calyx of Thomson navel fruitlets were measured and their relations with abscission and mineral nutrition of fruitlets as well as the effect of different treatments on them at June drop were evaluated. A randomized complete block design (RCBD) experiment was performed with 8 treatments and 4 replicates. Treatments were as follows: 1. control; 2. urea (1%); 3. urea + 2,4-D (15 mg l-1); 4.urea + GA3 (15 mg l-1); 5.urea + sucrose (1%); 6.urea + ZnSO4 (0.5%); 7. urea + ZnSO4 + 2,4-D; and 8. urea + ZnSO4 + GA3. Results showed that abscission had a significant negative correlation with auxin and a significant positive correlation with cellulase and polygalacturonase of the calyx. The control group had the lowest auxin and the highest cellulase in calyx. Maximum effect (Approximately 24% reduction in abscission) was obtained after foliar application of urea + sucrose (treatments 5). The use of urea alone or in combination with 2, 4-D and GA3 had no effect on abscission; however, using it in combination with sucrose was the most efficient treatment in this experiment. Furthermore, the combination of urea and Zn provided an effective treatment. A majority of micronutrients (Mg, Fe, Mn, Zn, Cu and B) had a positive correlation with auxin and a negative correlation with enzymes. Therefore, nutritional management and providing an appropriate condition to maximize photosynthesis can balance physiological metabolism and reduce fruitlets abscission.
