Plant Productions
Year:2016 | Volume:38 | Issue:4|Papers Count:12

Potassium plays an important role in improving plant tolerance to a biotic stresses such as salt stress. In order to evaluate the effect of potassium on alleviating the adverse effects of salt stress by monitoring the activity of some antioxidant enzymes, the grain yield and chlorophyll content of two durum wheat cultivars (Behrang and Yavarous), a pot experiment was carried out based on randomized complete block design with three replications with treatment levels including: control (no salt), 150 mm NaCl (Sodium Chloride), salt 150 mm NaCl with two levels of 300 and 450 mg K kg-1 soil as potassium sulfate and two levels of 30 and 45 mg K kg-1 soil as nano chelate potassium 27%. The grain yield of both cultivars was decreased under salt stress, but the combination of potassium and NaCl alleviated symptoms of the individual salt stress by enhancing the activities of antioxidant enzymes compared with individual salt stress. Both cultivars showed similar responses to salinity in combination with forms and rates of potassium under stress conditions for some traits, a though the activity of acerbate peroxides and glutathione reeducates was higher in Behrang cultivar. Totally, these findings showed that salinity in combination with forms and rates of potassium was more effective in Yavarous than in Behrang cultivar

This research was done to evaluate the effects of planting date and concentration of Hoagland nutrition solution on the yield and quality of strawberry fruit cv. Camarosa grown in Shahid Chamran University of Ahvaz. The research plan was designed as factorial based on completely randomized blocks (RCBD) with two factors of planting date (at three levels of 1 Dec., 20 Dec. and 10 Jan.) and concentration of Hoagland nutrition solution (at three levels: one-third, two-third and full strength Hoagland) with three replications. The results showed that a maximum flower and inflorescence number were obtained in plants which were fertigated with full strength Hoagland and planted at first and second planting dates (26.33 and 5.33, respectively). Also maximum fruit set ratio (74.86%) was recorded in nutrition with full strength Hoagland and planting date of 20 Dec. Maximum fruit weight (12 g), fruit number (14.33) and plant yield (172.77 g) were obtained under the nutrition with two-third strength Hoagland and 1 Dec planting date. However, the nutrition with full strength Hoagland nutrient solution having the best effects on fruit quality resulted in maximum vitamin C and fruit firmness (at first planting date) and maximum total soluble solids (at all three planting dates), but there were no significant differences with the results obtained for nutrition with two-third Hoagland. Based on the results and considering the high costs of producing nutrient solutions for hydroponics culture and also the short growth cycle of strawberry plant in Ahvaz to produce appropriate yields and high quality strawberries, planting on Dec 1 and nutrition with two-third strength Hoagland are recommended

The aim of this study was to investigate the sole and combined effects of drought and salinity stresses on some physiological characters of two canola varieties in Ahvaz as outdoor pot experiment. This factorial experiment was based on randomized complete block design. Results showed that both salinity and drought stresses decreased seed yield, shoot dry weight, root dry weight, harvest index, biological yield, plant height, number of branches per plant and relative water content of leaf (RWC). Drought and salinity stresses increased SPAD value and relative membrance permeability (RMP). However, combined stress had a greater effect on these parameters than each sole stress. In the salinity stress, a significant positive correlation was observed between relative membrance permeability and shoot dry weight (r= -0.93**). Also, a significant negative correlation was found between relative membrance permeability and relative water content in combined stress (r= -0.94**). Relative water content was reduced because of damage to the membranes and increase of electrolytes leakage. Generally, Hyola401 variety exhibited better defensive mechanisms and more efficiency than Shirale in maintaing relative water content and relative membrance permeability in salinity, drought and combined stresses. The study showed that Hyola401 was more tolerant than Shirale under salinity, drought and combined stresses.

Nitrogen is considered as an essential nutrient for plants and could be taken up in large amounts by plants. Nitrogen fertilizers are known to have beneficial effects when added to pistachio and other fruit trees. But the nitrogen assimilation of Pistacia species in response to salinity, including uptake and NO-3 reduction, has not been well understood. In this study, nitrate reductase activity, total amino acids, nitrate, calcium and sodium accumulation were evaluated in seedlings of Pistacia vera L. ̒ Badami Zarand̕ in response to sodium chloride (0, 75, 150 mm) and calcium nitrate (0, 10, 15 mm). Results showed that by increasing the level of salinity, nitrate reductase activity in leaves and the concentration of nitrate, total amino acids and calcium (Ca2+) were reduced in the leaves and roots of P. Vera seedlings. Calcium nitrate induced a significant increase in both the root and leaf nitrate and total amino acids or nitrate reductase activity in leaf under NaCl stress. Calcium nitrate, also, significantly increased root/ leaf total amino acids ratio and decreased Na+/Ca2+, ratio in the roots. Results showed that salinity affects the nitrate assimilation in P. Vera plants. Also, results suggest an efficient salt protective mechanism in P. Vera seedlings mediated by free total amino acids and calcium ions

In order to investigate the effects of mycorrhizal fungi, phosphatic biofertilizer and manure application on yield and quantitative and qualitative criteria of coriander an experiment was conducted at Khoramabad (Lorestan) during the growing season of 2013. The experiment des was conducted as factorial based on a randomized complete blocks design with 18 treatments and three replications. The factors were mycorrhizal inoculation in two levels, phosphatic biofertilizer and manure in three levels. The highest concentration of P in seed (3.67 %), leaf total carotenoid (2.39 µg ml-1) Biomass yield (3931.7 kg ha-1), seed yield )1780.67 kg ha-1) and harvest index (36.08%) was obtained in inoculation with Mycorrhiza, consumption of 70 kg ha-1 phosphate biofertilizer and 20 ton ha-1manure and they accounted for 51,168, 80 and 27 percent more than chemical control. Positive and synergistic interactions were obtained between Mycorrhizal inoculation × phosphate biofertilizer on leaf total carotenoid, seed yield and harvest index. According to the results of this research, inoculation with mycorrhizal produced the maximum grain yield, biological yield and harvest index compared to phosphate biofertilizer and manure.

In order to investigate the effect of different concentrations of putrescine and wax coating on qualitative and quantitative characteristics of ‘Kara’ mandarin in storage, an experiment was performed based on a completely randomized design (CRD). The effect of four levels of coating including BRITEX commercial wax, 0.2, 0.4 and 0.6 mm putrescine was studied on qualitative and quantitative characteristics of this cultivar in 3 replications and in three stages (20, 40 and 60 days of storage). Results showed that the coating type, storage time and interaction between them were significant at 1% on Kara mandarin fruits characteristics including fruit weight loss, skin to pulp ratio, fruit juice percentage, total soluble solid (TSS), TSS/TA ratio and vitamin C, but they were not significant on pH and titratable acid (TA). Generally, among all applied treatments, 0.2 mm putrescine application and the storage for 40 days coould be introduced as the most effective treatment to maintain quality of Kara mandarin and it can be used to improve the postharvest life of this fruit

In order to determine the optimum irrigation interval and nitrogen fertilizer rate for dill in Kermanshah climate conditions, an experiment was conducted as split plot design with three replications at Research Farm, Razi University in 2013. The Main plot and irrigation interval, included three levels (irrigation interval of 4, 6 and 8–day). The Split plot, nitrogen fertilizer, included four levels (nitrogen rate of 0, 100, 200 and 300 kg ha-1). The Studied traits included seed yield, biological yield, leaf and stem yield, umbel number per plant, umbellate number per umbel, 1000-seed weight, harvest index, plant height, stem diameter, leaf relative water content, chlorophyll-a, chlorophyll-b, total chlorophyll and carotenoides content. Leaf chlorophyll was measured by spectrophotometer. Results showed that the urea application of 300 kg ha-1 with the irrigation interval of 4-day produced the highest seed yield. Irrigation interval and nitrogen fertilizer had no significant effect on umbel number per plant, umbellate number per umbel, biological yield, stem and leaf yield, plant height and stem diameter. The nitrogen fertilizer application of 300 kg ha-1 had the highest harvest index. The irrigation interval of 8-day with the urea application of 200 kg ha-1 had the highestchlorophyll-a, chlorophyll-b and total chlorophyll content among major treatments. For the research is required to talk in to account the study of drought at different growth stages in dill.

Many pear genotypes and cultivars exist in the west part of Iran. Some of these cultivars have has unique nutritional or storage ability traits. The current study was carried out to study biophysical and biochemical changes of pear fruit during storage and ripening. Seven local pears and ‘Shah Miveh’ were harvested and stored at 1 ˚C up to 90 days. Sampling was carried out at harvest time and 30 days interval from the cold storage. Some factors such as fruit weight loss, firmness, fruit density, dry matter percent, vitamin C and total phenolic content, titratable acidity (TA), total soluble solids (TSS) and pH were measured in each sampling time. The results showed that TSS increased from 13.2 to 15.98 percent in all cultivars during the storage time while the overall TA decreased. The vitamin C content decreased during the storage time and both the average value for cultivars and the rate of decrease were different in the studied cultivars. Fruit weight loss increased during study the and reached 10.1 percent by 90 days cold storage. The correlation among ascorbic acid, density and fruit firmness was observed so that the fruits with higher density value were firmer and the ascorbic acid content was higher in fruit with higher firmness. The correlation was observed between dry matter and fruit weight loss, so that dry matter increased in the high level of fruit weight loss.

Nowadays, the application of antioxidants and plant growth regulators is assumed to decrease the negative effect of different stresses. Ascorbic acid and Sodium nitroprusside have been substances that increase the resistance to biotic and abiotic stresses. To evaluate this on safflower (Carthamus tinctorius), a field experiment was carried out in split plot factorial based on randomized complete block with three replications. Two levels of irrigation, including 8 days interval (well watered) and 16 days interval (water deficit stress) were, in the main plot, and the foliar application of sodium nitroprusside in 3 levels (0, 50 and 100 µm) and Ascorbic acid in 3 levels (0, 10 and 20 mm) was in sub plots. Stress treatment was applied after plants establishment completely. The first foliar application of sodium niroprusside and ascorbic acid was performed in 63 and 65 days after sowing respectively and then repeated after 1 week. Water decreased membrane Electrical Conductivity (EC). The EC decreased by ascorbic acid foliar application. The EC increased significantly by sodium nitroprusside foliar application. The foliar application of sodium nitroprusside increased leaf area index. Chlorophyll b increased by sodium nitroprusside foliar application in well watered. 10 mm ascorbic acid foliar application increased Carotenoeid. Seed yield by the application of 100 µM sodium nitroprusside concentration was 13.2% more than control. Therefore, it seems that the foliar application of sodium nitroprusside with appropriate concentration can be helpful in reducing stress intensity.

In this research, the effect of ovary co-culture on androgenesis efficiency in anther cultures of four cultivars of cucumber was studied. A factorial experiment based on Completely Randomized Design with three replications was used in this study. Cultivars of cucumber (Beta Alfa, Esfahani, Basmanj and Korki), type of culture medium (solid and liquid) and number of cucumber ovaries (0, 10, and 20) were considered as the experimental factors. Different cultivars of cucumber, two type of culture medium, different numbers of ovaries in culture medium, two-way interaction effects and triple interaction effect of cultivar × culture medium × ovary number showed significant differences (p<0.001) for the traits of callogenesis percentage (except for the interaction effect of culture medium × ovary number) and the mean number of embryo per anther. The Use of MS liquid medium without any ovary in Esfahani cultivar (90% callogenesis), solid medium containing 10 ovaries in Korki cultivar (86.66% callogenesis) and also solid medium containhing 20 ovaries in Basmanj cultivar (76.66% callogenesis) showed the highest callogenesis percentage. The Application of 10 ovaries in solid medium in Korki and Esfahani cultivars produced the highest embryogenic calli (60% and 56.66%, respectively). Furthermore, the highest mean number of embryo per anther obtained with 10 ovaries in solid medium in both cultivars of Esfahani and Korki (0.76 embryo per anther). Finally, use of solid MS medium containing 10 ovaries in Beta alfa, Esfahani and Korki cultivars and also 20 ovaries in Basmanj cultivar increased the embryo production in cucumber anther culture.