مجله علوم گیاهان زراعی ایران
سال پنجاه و چهارم شماره 1 (بهار 1402)

A field experiment was carried out as a randomized complete block design with four replications to investigate the agronomic traits and grain yields of sesame and soybean intercropping at Research Farm of Sari Agricultural Science and Natural Resources University for two years (2018-2019). The mixing ratios were 25:75, 50:50, 75:25 (soybean: sesame, respectively), and monoculture of two crops. Results showed sesame monoculture had the highest branches and capsules per plant. In the Soybean crop, the mixing ratio of 50:50 was more successful in producing the branches and pods per plant than other mixing ratios. Also, sesame and soybean monocultures had the highest grain yield with an average of 2077.43 and 4365.32 kg. ha-1, respectively,. The mixing ratio of 50:50 and 75:25 (1.17 and 1.01 in average, respectively) had higher LER than one. Finally, the more significant contribution of complementary effect (83.98 %) and selective effect (76.73 %) on grain yield at 50:50 and 75:25 mixing ratio increased the productivity of the intercropping system, respectively.  Meanwhile, the little increase in efficiency in the 75:25 mixing ratio was related to the 76.73% contribution of the selective effect and the competitive dominance of soybeans in the intercropping.

Drought stress is one of the most important abiotic stresses limiting wheat production. To improve the growth and yield of wheat under drought stress, a factorial experiment was performed based on a randomized complete block design with three replicates in the research greenhouse of the University of Tehran. Experimental treatments included irrigation at two levels (well-watered and drought stress) and vitamin foliar application at four levels (control, thiamine, pyridoxine, and thiamine+pyridoxine). The results showed that drought stress reduced the relative water content of flag leaves by 21%. The use of vitamins increased the amount of this trait compared to the control treatment. The chlorophyll number (SPAD) of flag leaf increased under drought stress, but the use of vitamins had no significant effect on this trait. Drought stress had an increasing effect on leaf free proline content and foliar application of thiamine and its combination with pyridoxine, respectively, increased this trait by 53% and 32% compared to treatment without foliar application under drought stress conditions. Also, the percentage of electrolyte leakage and malondialdehyde content of flag leaf under drought stress increased by 31% and 103%, respectively. Vitamins reduced the amount of malondialdehyde and had no significant effect on the percentage of electrolyte leakage. Drought stress also reduced wheat grain and biological yields. Foliar application of vitamins showed an additive effect on these traits compared to the control treatment. The highest grain yield per plant was obtained in treatments of pyridoxine (1.1 g) and its combination with thiamine (1.2 g).

The objective of this study was to investigate the effects of foliar application of amino acids of proline, valine and alanine on some morphological traits, yield and yield components of chickpea (Mansouri cultivar) under different irrigation regimes. Therefore, an experiment was conducted in a randomised completely block design with a split-plot arrangement of treatments in a research farm of the Faculty of Agriculture, Tarbiat Modares University, Iran, during the 2018-2019 and 2019-2020 growing seasons. The experimental treatments included three different irrigation regimes (namely regular irrigation, moderate water stress, and severe water stress) as main plots and different foliar applications of amino acids (including 0.5 g.l-1 of proline+valine, proline+alanine and alanine+valine, 1 g.l-1 of a commercial amino acid from Agrares and two treatments with distilled water and no foliar application) as subplots in three replicates. The results showed that plant height, leaf area, 1000-seed weight, grain yield, chlorophyll a and b content, and total chlorophyll were significantly affected by irrigation regimes, foliar application of the amino acid, and their interaction. The highest grain yield (3924.05 kg.ha-1) was obtained under regular irrigation×foliar application of proline+alanine and the lowest grain yield (687.27 kg.ha-1) was obtained under severe water stress×no foliar application. Moreover, a significant increase of 69% in plant height was observed in the interaction regular irrigation×foliar application of proline+alanine compared to the control treatment. Accordingly, regular irrigation and combined application of the above amino acids (under water stress conditions) are recommended to reduce the adverse effects of drought stress on chickpea (Mansouri cultivar).

Intercropping is one of the ways to achieve sustainability in agriculture. However, studying its economic and competitive indicators is critical to optimizing production. Therefore, this study was conducted to investigate the status and amount of consumption inputs in monoculture and intercropping systems in Khuzestan province. The required information was collected through a questionnaire and a field survey of 111 farmers. The results showed that intercropping with a land equivalent ratio of 1.40, gross and net production value of 7269.23 and 4090.19 dollars per hectare, and superiority in benefit-cost ratio, system productivity, and economic efficiency has a higher yield than okra monoculture. Also, the total cost of intercropping with 3179.04 dollars per hectare and input energy with 81269.27 megajoule per hectare were 23.20 and 3.18 % higher than monoculture, respectively. According to the results of this study, intercropping of okra and cucumber with superiority in economic and competitive indicators can be the optimal cultivation pattern of okra in Khuzestan province. However, it is necessary to optimize the intercropping input to reduce the total cost and input energy.

Some essential factors effectively reduce wheat yield; one of the most critical factors is weeds. The effect of this factor can vary at different fertilizer levels. To investigate the effect of different densities of wild oat in different nitrogen fertilizer levels on the wheat traits, an experiment was conducted in the form of split plots and in a randomized complete block design with three replications. Treatments included the application of 30, 60, 100 and 120% of wheat nitrogen fertilizer requirement and densities of zero, 25, 50, 75 and 100 wild oat plants per m2. The results showed that the highest wheat grain yield (871.60 g/m2) and radiation use efficiency (1.49 g Mj-1) obtained at 120% fertilizer level and the absence of weeds, and the lowest obtained at 30% nitrogen and 100 plants per m2. The highest dry weight yield (381 g/m2) and radiation use efficiency (1.6 g Mj-1) of wild oats were obtained at 100 plants/m2 density and at the highest level of nitrogen fertilizer. In general, increasing the presence of wild oats and increasing its density under conditions of improper application of nitrogen can intensify interspecific competition and ultimately lead to yield reduction.

In order to evaluation of phytoremediation capability of Chenopodium quinoa Willd along with application of three types of biochar in cadmium contaminated soil, a factorial experiment was conducted in a completely randomized design with four replications in 2021. The treatments of this experiment include five levels of Cd (0, 25, 50, 75, and 100 mg Cd / kg soil from the source of cadmium nitrate) and four types of biochar (pomegranate and plum wood, wheat straw, North forest wood, and control). In this experiment, root dry weight and shoot dry weight decreased by 88.7 and 126.8% in response to increasing cadmium concentration, respectively. Pomegranate and plum wood biochar and wheat straw biochar increased root dry weight (18.8% and 40%, respectively) and shoot dry weight (35.8% and 79.4%, respectively). While the North forest wood biochar reduced root dry weight by 18.8% and shoot dry weight by 31.8%, with increasing cadmium concentration in soil, roots and shoots of quinoa increased by 484883.3, 90634.7, and 115805.4%, respectively. Application of pomegranate and plum wood biochar and wheat straw biochar reduced the concentration of cadmium usable in soil, cadmium concentration in roots and shoots. While, the North forest wood biochar on all levels, except the control, increased the concentration of usable cadmium in the soil, the concentration of cadmium in the roots and shoots of quinoa. With increasing cadmium concentration, tolerance index decreased by 129.4% compared to control. Due to the high tolerance index, translocation factor and bioaccumulation factor, the use of this plant in remediation can be recommended. On the other hand, the use of pomegranate and plum wood biochar and wheat straw biochar can reduce the concentration of cadmium in soil, root and shoot, as well as can improve plant yield, therefore, can be used for phytostabilization and reduce heavy metals in plant organs. On the other hand, the use of North forest wood biochar with the ability of increasing the concentration of cadmium in the soil, root and shoot can be used as an aid to increase of plant extraction. According to the results of this study, farmers can be advised to use pomegranate and plum wood biochar and wheat straw biochar in fields containing heavy metals such as cadmium to reduce these heavy metals. On the other hand, the use of North forest wood biochar should be avoided due to increased mobility of heavy metals in the fields.

Hormones play an important role in grain filling regulation (as a reproductive sinks) and the demand for assimilates from current photosynthesis and remobilization sources as well. The objective of this study was to improve sink strength through GA3 application, measuring remobilization and yield under terminal drought stress. Twenty wheat cultivars were cultivated in a split split plot arrangement based on RCBD design with three replications, full irrigation and 40% of field capacity being main plots, GA3 foliar application (60 μM) and control (No GA3) were regarded as sub-plots and wheat cultivars were sub-sub-plots. Grain yield, biological yield, yield components and remobilization (by internodes) were estimated. Significant variation among cultivars was observed under both full irrigation and stress treatments. However, the response of the cultivars to the gibberellin application was almost the same. Drought stress reduced grain yield (33%), biological yield (20%), 1000-seed weight (14%), number of grains per spike (14%) and remobilization (8%), but application of gibberellin increased these traits under both conditions. Gibberellin foliar application at the wheat pollination stage had a positive effect on sink strength and remobilization, especially under full irrigation conditions. Under drought stress conditions, the positive effect of gibberellin application on the studied traits was less due to the reduction of grain filling period. Based on the results of present experiment, foliar application of gibberellin is not recommended under drought stress conditions.

Salinity is one of the main reasons of reduction in plant growth and production. One of the most low-cost ways to use saline soil and water is cultivating resistant plants to salinity. We designed an experiment to evaluate salinity resistance of 107 genotypes of Lens culinaris under control conditions. The experiment was designed in completely randomized blocks with three replications in 12dS.m-1 NaCl. The results indicated that four weeks after salt stress, thirty nine genotypes showed survival rate of 76-100% and nine genotypes had a 100% survival. Based on factor analysis, four factors explained 72% of changes in data, which first and second factors explained the most changes in data variants included survival percent, contents of chlorophyll a, contents of chlorophyll b, carotenoids, chlorophyll a/chlorophyll b, total content of phenol, content of proline, DPPH, Na/K, and dry matter. Then, we used these two factors to determine distribution and distinguish best genotypes in results which were MLC250, MLC263, MLC281, MLC285, MLC286, MLC291, MLC292, MLC294, MLC296, MLC299, MLC300, MLC301, MLC307, MLC311, MLC314, MLC316, MLC323, MLC327, MLC357, MLC362, MLC363, MLC364 and MLC371. According to the cluster analysis, genotypes were classified into 5 groups. The third and fifth group showed the best results in survival percent and other traits; therefore, we suggest these genotypes use for salt tolerance breeding programs in lentil.

The Gamma aminobutyric acid (GABA) content as a free amino acid which is involved in reduction of oxidative stress damage and stress adaptation in the cell is adjusted by various routes, including the GABA shunt pathway. In this experiment, Gama -aminobutyric acid (GABA), Hydrogen Peroxide (H2O2), activity of GABA transaminase (GABA-T) and relative expression of Glutamate Gecarboxylase1 (GAD1) gene in cold-tolerant (Sel96th11439) and cold-sensitive (ILC533) chickpea (Cicer arietinum L.) genotypes under cold stress (4◦C) as a factorial experiment in a Completely Randomized Design were studied. In tolerant genotype H2O2 content after a significant increase on the first day of cold stress decreased significantly on the sixth day of cold stress compared to control conditions (up to 4.7%) while its accumulation was observed in sensitive genotype (up to 50%). Based on H2O2 adjustment as a damage index, these results indicated a relative acclimation to cold stress in tolerant genotype. Under cold stress, GABA content in tolerant genotype was higher compared to sensitive genotype (up to 14%). In this experiment, under cold stress, in tolerant genotype increasing GABA content was accompanied with an increase in GABA-T activity and relative expression of GAD1 gene as regulatory routes of this metabolite (up to 3- and 17-fold, respectively). The maximum and minimum activities of catabolic and anabolic pathways was observed in tolerant genotype on the sixth day of cold stress, respectively. Therefore, under cold stress, the accumulation of GABA in tolerant genotype led to reduced cell damage (H2O2 results) and improved cold tolerance.

Industrialization and destructive human activities have led to a rapid spread of heavy elements contamination in soil. The purpose of this study was to investigate the effect of silicon and salicylic acid on yield and physiological traits of corn in Rahimi and Molavi farms (contaminated with heavy metals and located near lead and zinc factors in Zanjan) in 2020, by using a factorial design based on randomized complete blocks. Factors included spraying salicylic acid at zero, 600, 1200, and 1800 µM, and spraying nanosilicon at zero, 600, 1200 and 1800 mM. Based on the results of soil analysis, lead, zinc, and cadmium concentrations in both fields were higher than the allowable limit and this heavy metal contamination was more severe in Rahimi field. Heavy metal contamination reduced plant height, grain yield and yield components, biological yield, chlorophyll content, and proline levels. The highest grain yield and grain weight were obtained with 1800 µM salicylic acid and 1200 mM nanosilicon treatments, and the lowest with the control treatment (without salicylic acid or nanosilicon). The highest chlorophyll content was obtained from 1800 µM salicylic acid treatment on Molavi's farm and the maximum amount of chlorophyll was observed in 1800 mM nanosilicon treatment. Overall, the treatments improved the yield, chlorophyll content, and relative water content of corn leaves. It is recommended to spray 1800 µM salicylic acid and 1200 mM nanosilicon on the corn fields in this area to increase the stress tolerance under heavy metal conditions.

The use of biological stimulants in order to produce environmentally friendly biological products in conjunction with modern agriculture can increase the qualitative and quantitative growth of plants and reduce the effects of environmental stresses on them. In order to investigate the effect of Trichoderma harzanium, carrageenan and saffron extract containing silver nanoparticles on the morphophysiological and phytochemical properties of Melissa officinalis, this experiment was performed in 2020 as a randomized complete block with three replications in Fereydunkenar. This study includes ten treatments that include: Carrageenan 100 ppm, carrageenan 300 ppm, carrageenan 600 ppm, saffron extract containing silver nanoparticles 125 ppm, saffron extract containing silver nanoparticles 250 ppm, saffron extract containing silver nanoparticles 250 ppm, saffron extract containing silver nanoparticles 500 ppm, Trichoderma harzanium 100 ppm, Trichoderma harzanium 200 ppm, Trichoderma harzanium 400 ppm and distilled water (control) were applied on stages 4, 8 and 12 leaves. Morphological and phytochemical characteristics were assessed at the beginning of flowering. The results showed that the highest (6.3 cm) length and maximum (4.3 cm) leaf width were obtained from the treatment of saffron extract containing silver nanoparticles with a concentration of 125 ppm, which is 61% higher than the control treatment. Also, the highest dry weight (59 g) was related to carrageenan treatment at a concentration of 600 ppm, which was 4.9 times higher than the control treatment. Moreover, the highest (78.1%) antioxidant activity and the highest (80.4 mg/g fresh weight) anthocyanin levels were related to Trichoderma harzanium treatment at 400 ppm.

Studying the genetic structure of populations and primary genetic reserves is one of the main priorities of maize breeding programs. Molecular markers are highly efficient in estimating the breeding value of genotypes. A total of 73 maize genotypes prepared from different research centers (Razi University of Kermanshah, Khorasan Razavi Agricultural and Natural Resources Research Center, Seed and Plant Improvement Institute (SPII) of Karaj, were evaluated in a completely randomized design with three replications under normal and salinity stress of 8 dS/m in pot conditions. Based on the results of analysis of variance a significant difference was observed between genotypes in most of the studied traits in each one of the conditions; which indicates the existence of high diversity between the studied genotypes. Estimation of breeding value for 25 traits in 73 genotypes in each one of normal and salinity stress conditions was performed using BLUP by exploiting kinship matrix calculated based on SNP molecular data. According to the sum of ranks of breeding values for all studied traits genotypes 17, 4, 8 and 3 under normal conditions, and genotypes 3, 17, W153R, 9, 4 under salinity stress conditions had the highest rank in view of breeding value. Also, P19 L7 Kahriz, P15L4, W37A, P6 L1 and P14L1 Kahriz genotypes under normal conditions, and P6 L1, P19 L7 Kahriz and P14L1 Kahriz genotypes under salinity stress had the lowest breeding values. In general, considering all the studied traits in two conditions, genotypes 17, 3 and 4 showed high breeding value and genotypes P19 L7 Kahriz and P6 L1 showed lower breeding value, respectively. Genotypes with high breeding value have the greatest potential in transmitting the value of traits to the next generation; therefore, they can be introduced as desirable parents to improve these traits in maize breeding programs.

Considering the limited production of edible oil in the country, selectivity of the genotypes of valuable oilseeds like sesame is important. A randomized complete block design with three replications was conducted in the research farm of the Ferdowsi University of Mashhad in 2021, to investigate 20 sesame genotypes' yield, and yield components and determine the most important traits affecting the yield. The results showed that Afghan1, Afghan3, and Afghan5 genotypes had the highest number of capsules plant-1 , 1000-seed weight, biological yield, and seed yield. Also, the correlation analysis between the traits showed that seed yield had a positive and significant correlation with the number of capsules per plant (r=0.58**), and 1000-seed weight (r=0.42**), respectively. Based on the principal component analysis, in total two components explained 83.1% of the variation in data. The first component explained 57.7%, and the second component showed 15.2% of the most changes in variation between genotypes. Then, these two components used to determine the distribution and distinguish the best genotypes in the results. As a result of cluster analysis, genotypes were categorized into three groups based on yield and yield components. The genotypes of the third group (Afghan1, Afghan3, Afghan4, Afghan5, and Afghan7) had a higher average in the investigated traits than other groups. These results indicate that the most effective traits in sesame yield are the number of capsules per plant and the 1000-seed weight. Since high yield is one of the important breeding goals in sesame; therefore, genotypes with these characteristics can be introduced as superior genotypes.

Plant growth regulators are the most important factors that regulate crop production. Hence, this study was conducted to evaluate the effect of some plant growth regulators on physiological traits, gas exchange variables and grain yield quality and quantity of wheat in Razi university, Iran, in 2013-2014 crop year. A factorial experiment based on randomized complete block design (RCBD) with three replications was used. In this study, the first factor included 10 bread wheat cultivars (Zare, Parsi, Sivand, Pishtaz, Bahar, Azar 2, Bezostaya, Gaspard, Sirvan, and Marvdasht) and also the second factor at four levels included foliar application of 50 μM concentration of cytokinin, auxin, gibberellin and lack of foliar application (control) at flowering and booting stages of the spike. The results showed that there were significant differences among cultivars in terms of agronomic and physiological traits. Sivand and Parsi cultivars had the highest grain yield, biological yield, harvest index, number of grains per spike, thousand grain weight, hectoliter weight, photosynthetic rate and chlorophyll a, but Azar 2 cultivar had the lowest of the above traits. The results showed that application of plant growth regulators increased grain yield, biological yield, harvest index, thousand grain weight, photosynthesis rate, soluble proteins content and crude protein. Among the investigated plant growth regulators, the application of 50 μM of cytokinin caused the highest increase in the rate of plant photosynthesis (18.4%).

Fusarium wilt caused by Fusarium oxysporum L. is one of the most important destructive flax diseases that markedly decrease the production and yield of this crop. The cultivation of flax cultivars resistant to F. oxysporum is the most effective method for managing this disease. In this study, the changes in content of phenylalanine ammonia lyase, peroxidase and polyphenol oxidase enzymes, total protein, proline and soluble sugars were measured in 12 different genotypes of flax infected to wilt Fusarium and non-infected conditions under greenhouse conditions. The experiment was conducted in a randomized complete block design with three replications. 21 days after inoculation of the plant with the pathogen, biochemical components changes were measured by spectrophotometry. Based on the results of ANOVA, the soluble sugars content in infected genotypes was higher compared to control and healthy genotypes. Also, this parameter increased in resistant and highly resistant genotypes of flax, meanwhile this trait decreased in susceptible genotypes in contaminated conditions. The activity of phenylalanine ammonia lyase, peroxidase and polyphenol oxidase enzymes as well as proline content in leaves of resistant and highly resistant genotypes were significantly increased in wilt Fusarium infected treatment. Total protein content in non-infected genotypes of flax was higher than infected genotypes. Therefore, increasing the activity of antioxidant enzymes, proline content and soluble sugars can play a possible role in inducing resistance to Fusarium wilt disease in flax genotypes.

To investigate the effect of different cultivation arrangements and levels of nitrogen on the yield, yield components and fatty acids profile of sunflower, this study was conducted as a split plot experiment in a randomized complete block design with three replications in 2021. Spatial arrangement in five levels (normal rectangle, wide rectangle, square, triangular, and mixed cultivation systems) as the main plots and the levels of nitrogen chemical fertilizer (urea) in three levels (application of 100%, 75%, and 50% of urea fertilizer requirement) were placed in sub-plots. The maximum dry weight of leaves and stems was obtained in the triangular planting arrangement at all three levels of nitrogen application. So that the triangular planting arrangement had a 30% increase in dry weight of leaves and stems compared to the wide rectangular planting arrangement. The normal rectangular cultivation treatment with 100% nitrogen application had the highest amount of palmitic acid fatty acid, and the mixed and triangular cultivation treatment with 50% nitrogen application had the highest percentage of stearic acid and oleic acid, respectively. While, the wide rectangular cultivation treatment with 75% nitrogen application had the highest linoleic acid compared to other treatments. In addition, the results showed that the yield, and yield components in the triangular system were more than the other investigated systems, so that by reducing the nitrogen consumption by 50% in this cultivation system, the yield did not have any significant difference with 100% urea application. Therefore, using the spatial arrangement of triangular cultivation is introduced as the best cultivation system for sunflower.