مجله تولید و فرآوری محصولات زراعی و باغی
سال چهاردهم شماره 1 (پیاپی 101، بهار 1403)

Investigating the role of agronomic factors is very important in improving the quantitative and qualitative characteristics of oilseeds. In order to determine the composition of fatty acids and grain yield in camelina (Camelina sativa L.), a two-year experiment (2017-19) was conducted in Karaj, Iran. The experiment was carried out as a split plot-factorial in a randomized complete block design with three replications, where the planting date (7th Oct., 22nd Oct., and 6th Nov.) in main plots and planting density (40, 50 and 60 plants m-2) and humic acid (including non-application and application of 0.003 HUMAX 95-WSG) in two stages of 4-leaves and stem elongation were considered in sub-plots. The highest grain yield with an average of 2485 kg ha-1 was obtained on 7th Oct., at 40 plants m-2 and application of humic acid. In addition, application of humic acid in delayed planting date (6th Nov.) and 40 plants m-2 showed the highest positive effect on 1000-grain weight and grain yield (wit increases of 17.8 and 32.7%, respectively) compared to non-application. Also, application of humic acid in delayed planting date (6th Nov.) and 40 plants m-2 showed the highest percentage increase of oleic acid (0.9%) compared to non-application. Furthermore, application of humic acid in all normal (7th Oct.), relatively late (22nd Oct.) and late (6th Nov.) planting dates, caused a significant decrease of erucic acid and glucosinolate concentrations compared to non-application. Therefore, application of humic acid is beneficial to camelina growth and grain yield, particularly when sown in a delayed date.

To compare tolerance and sensitivity indices of sesame genotypes to water stress in Ahvaz (south-west of Iran) conditions, an experiment was conducted in Research Farm of Agricultural Sciences and Natural Resources University of Khuzestan, south-west of Iran, in summer 2018. The experimental design was split plot based on a randomized complete block design with four replicates. Experimental factors were three levels of irrigation (I1; fully irrigated, I2: changing altered irrigated and I3: fixed altered irrigated) in main plots and six sesame genotypes in subplots. The yield of studied genotypes showed a significant difference in different levels of irrigation. Genotype Shushtar produced the highest grain and oil yield and showed good performance in both normal and low irrigation conditions. The examined genotypes had significant differences in terms of Stress Sensitivity index (SSI), Tolerance Index (TI), Productivity Mean (PM), Harmonic Mean (HM), Yield Stability Index (YSI), Geometric Productivity Mean (GPM), Stress Tolerance Index (STI), Stress Damage Index (SDI), Modified Stress Tolerance for appropriate conditions (MSTI1), Modified Stress Tolerance for non-appropriate conditions (MSTI2), and Yield Reduction Index (YRI).  In general, the best indicator for evaluation of tolerance and susceptibility of sesame genotypes was stress tolerance index (STI). The most tolerant and sensitive genotypes were Shushtar and Halil genotypes, respectively.

With the aim of evaluating the effects of salicylic acid and brassinosteroid application on some physiological traits and arsenic accumulation in spinach under arsenic stress conditions, an experiment was conducted in a factorial experiment in the form of a randomized complete block design with four replications in the year 2022 in the Nutrition Research Center, Department of Food Hygiene and Quality Control, School of Nutrition and Food Sciences, Shiraz University of Medical Sciences, Iran. The experimental factors included salicylic acid (0, 0.5, and 0.75 mM), brassinosteroid (0, 0.5, and 0.75 µM), and arsenic stress (0, 50, and 100 µM). Arsenic stress, especially at 100 µM, reduced the net photosynthetic rate, transpiration rate, stomatal conductance of spinach leaves and biomass. Arsenic stress increased the concentration of malondialdehyde, hydrogen peroxide, osmolytes, as well as antioxidant enzymes activities in spinach plants. Application of brassinosteroid and salicylic acid significantly increased activities of antioxidant enzymes (peroxidase, ascorbate peroxidase, and superoxide dismutase), osmolytes accumulation (carbohydrates and proline) and spinach biomass; in contrast, application of brassinosteroid and salicylic acid decreased the concentration of malondialdehyde and hydrogen peroxide in spinach plants under arsenic stress conditions. Arsenic accumulation was higher in spinach roots than in leaves. Under 100 µM arsenic stress, the application of different concentrations of salicylic acid and brassinosteroid, individually and in combination, significantly reduced arsenic accumulation in spinach, with the highest positive effect being observed in the treatment of 0.75 mM salicylic acid + 0.75 µM brassinosteroid. In conclusion, brassinosteroid and salicylic acid application increased the tolerance of spinach plants against arsenic stress by improving gas exchange, activity of antioxidant enzymes, accumulation of osmolytes, stability of the membranes, and as a result plant biomass; the positive effects of brassinosteroid and salicylic acid together were greater than that of brassinosteroid or salicylic acid applied separately.

Micronutrient elements play a key role in the formation of chlorophyll and function of photosynthesis, respiration, enzyme system and physiological processes of the plant and their deficiency has destructive effects on the growth, production and yield of the plant. This research was conducted in a factorial experiment based on a randomized complete block design with three replications on mung bean plant in the Research Farm of Bu-Ali Sina University, Hamedan, Iran, in 2019-2020 growing season. Two cultivars of Gohar and Partu and foliar spraying of zinc chelate, iron chelate, zinc nano-fertilizer, iron nano-fertilizer, and control (spraying solution with water) were tested. The maximum leaf area index (3.12), maximum growth rate (16.2 g m-2 day-1), and leaf area duration (157 day) were achieved by Gohar cultivar in the presence of foliar application of zinc nano fertilizer. Zinc nano-fertilizer had the greatest effect on the pods/plant (21.7), grains/pod (8.08), and grains/plant (164) of Gohar cultivar, which increased by 62, 22 and 62, 77.6 percent respectively, compared to the control. The highest biological yield (8599 kg ha-1) was obtained with Gohar cultivar when receiving foliar application of iron nanofertilizer and zinc nanofertilizer. The highest grain yield (2657kg ha-1) was obtained with Gohar cultivar subjected to nano-zinc foliar spraying, which was not significantly different from Parto cultivar in foliar spraying with zinc nano-fertilizer and caused 38% and 35% increases in grain yield of the two cultivars compared to the control, respectively. The highest harvest index was also obtained with Gohar cultivar supplemented by foliar spraying of zinc nano fertilizer, which increased the harvest index by 24% compared to the control. Foliar spraying of iron and zinc fertilizers caused significant increases in growth, biological yield and grain yield, as well as the content of these elements in the grain of both cultivars. The effect of zinc and iron nanofertilizers on the studied traits was more pronounced in Gohar variety than in Parto variety.

Drought is one of the most important abiotic stresses limiting the survival, growth, and productivity of plants in many regions of the world. This study was conducted to evaluate drought tolerance of the recombinant genotypes of two species of orchardgrass and smooth bromegrass based on clonal evaluation and stress tolerance indices. In this study, 36 genotypes selected from polycross populations of both species of orchardgrass and smooth bromegrass were evaluated in terms of phenological, agronomic and morphological traits under normal (50% water depletion from the root zone depth) and drought-stressed (90% water depletion from the root zone depth) conditions during 2013 to 2015 at the Research Farm of Isfahan University of Technology, Isfahan, Iran. To evaluate drought tolerance of the mentioned genotypes, five drought tolerance and susceptibility indices including stress tolerance indices (TOL and STI), mean productivity index (MP), geometric mean productivity (GMP) and stress sensitivity index (SSI) were calculated based on forage yield under drought stress (Ys) and non- stress (Yp) conditions. In both species, high genetic variation was observed among genotypes in terms of most of the studied traits and indices. In orchardgrass, the genetic coefficient of variation varied from 4.31% to 23.5% under normal condition, and from 1.31% to 21.3% under drought stress condition. In smooth bromegrass, the range of genetic coefficient of variation was variable from 2.05-21.4% under normal condition and 1.66-24.6% under drought stress condition. This indicated a high potential for improving these traits through targeted selection in breeding programs of the two species. Drought stress significantly affected most of the studied traits and reduced the genetic variability of traits except for days to ear emergence, days to pollination, percentage of dry matter yield of cut 1, and percentage of dry matter yield of cut 2 in orchardgrass, and percentage of dry matter yield of cut 1 and percentage of dry matter yield of cut 3 in smooth bromegrass. The amount of this reduction for dry matter yield of cuts 1, 2 and 3 was 47.5, 67.3, and 66.6 percent, respectively, in orchardgrass, and 37.4, 49.5, and 49.4 percent, respectively, in smooth bromegrass. Low heritability for forage yield (24.7, 13.5, and 25.9 percent for dry matter yield of cut 1, dry matter yield of cut 2, and dry matter yield of cut 3, respectively, in orchardgrass, and 59.5, 45.9, and 59.4 percent for dry matter yield of cut 1, dry matter yield of cut 2, and dry matter yield of cut 3, respectively, in smooth bromegrass) suggested that direct selection based on forage yield is not effective for the improvement of this trait. Though, indirect selection based on components of forage yield which have high heritability and high correlation with yield (i.e. plant height, stems/plant, and crown diameter in both species), would be more effective. In both species, selection indices of MP, GMP, and STI had a positive and significant correlation with forage yield (0.92, 0.75, and 0.75, respectively, under normal condition, and 0.61, 0.81, and 0.77, respectively, under drought-stressed condition, in orchardgrass; and 0.95, 0.92, and 0.88, respectively, under normal condition, and 0.91, 0.95, and 0.95, respectivel, under drought-stressed condition, in smooth bromegrass). Therefore, these indices were identified as desirable ones in the selection of drought tolerant cultivars in orchardgrass and smooth bromegrass. Based on the results of principal component analysis and drought tolerance and susceptibility indices, the genotypes of 13 and 14 in orchardgrass, and 13 and 32 in smooth bromegrass were identified as superior genotypes in terms of forage yield and drought tolerance. These genotypes can be used as superior parents for the development of genetic populations to improve forage yield and stress tolerance and create synthetic cultivars.

African violet (Saintpaulia ionantha Wendl.) belonging to the family Gesneriaseae is a very popular indoor plant. The aim of this study was to investigate the effect of red, blue, red and blue light (one part blue and three parts red) and white fluorescent on the vegetative and reproductive growth of African violet plants. The experiment was conducted in a completely randomized design with 4 treatments and 16 replications in the first phase and 16 treatments with 4 replications in the second phase. The tallest plants in the first and second phases were those treated with red light with an average of 8.2 and 12.5 cm, respectively. Plants treated with mixed blue and red light produced the highest leaves/plant in the first phase of the experiment. However, these plants reduced their number of leaves in the second phase when treated with the blue light. In the first phase, the fluorescent and red light alone developed the greatest canopy area (about 350 cm2), while in the second phase, the canopy area in fluorescent light reached its maximum rate (500 cm2). Similar results were observed for the leaf area. Blue light produced the highest flowers/plant in the first phase, although in the second phase, plants transferred from fluorescent light to the mixed blue and red light indicated increases in flowers/plant. The overall results of the experiment indicate that the blue light plays an important role in early flowering and the red light has an important effect on the rate of canopy extension.