Effects of vermicompost produced from cow manure on the growth, yield and nutrition contents of cucumber (Cucumis sativus)

An experiment was conducted to determine the effects of vermicompost on the growth, yield and nutrient contents of cucumber grown under the glasshouse conditions. This experiment was performed in completely randomized design with five replications. The base medium (control) was selected to be a mixture of 75% farm soil with 25% sand that had been substituted with 0, 10, 20, 30, 40, 50 and 60% by volume of cow manure vermicompost. The highest leaf area, stem numbers, stem and root dry weight, fruit yield, and chlorophyll content were resulted from substitution of base medium with10 and 20% vermicompost that were significantly different from control (P≤0.05). Further, increase in the vermicompost content of the base medium, reduced the stem height, leaf area, stem dry weight, root dry weight, and chlorophyll content. Plant yield was the lowest in the 50% and 60% vermicompost medium. Shoot macro and micro-nutrient content such as nitrogen, phosphorus, potassium, calcium, iron, zinc, manganese, and copper increased significantly in response to the increase in vermicompost ratio from 0 to 60%, therefore, the lowest and the highest of these nutrient contents were observed in the control and 60% vermicompost, respectively, and even in some cases, nutrients content reached the toxic levels

Effect of organic fertilizers on nutrients content and essential oil composition of savory (Satureja hortensis L.)

Application of organic fertilizers in the production of plants is aimed to eliminate or substantially reduce the use of chemical inputs and improve the growth and quality of plants. For instance, in present study, the effect of vermicompost and spent mushroom compost application on nutritional status and essential oil components of summer Savory (Saturejahortensis L.) was investigated. This experiment was conducted in the research greenhouse of Faculty of Agriculture at Mohaghegh Ardabili University using a layout of completely randomized design with five replications on Savory in 2014. Experimental treatments included different substrates that contained vermicompost, washed and unwashed spent mushroom compost in five levels (10, 20, 30, 40 and 50 Percent v/v). After flowering, the plants were harvested and parameters such as leaf area, leaf and plant dry weight, chlorophyll index of leaf and N, P, K, and Ca content and essential oil component of plants were measured. The results showed that the effect of organic substrates on macronutrient content and savory’s growth parameters was significant. The highest Nitrogen content (6.3%) and Phosphorus (0.98%) in savory shoot was obtained in a substrate supplemented with 40% vermicompost. Plants grown in the media containing 30% of vermicompost and 50% of washed spent mushroom compost (SMC) have higher potassium (3.19%) and calcium (2.48%) content, respectively. The lowest nitrogen, phosphorus and potassium content in the aerial part was obtained in the control treatment. Moreover, application of organic fertilizers significantly affected on savory’s essential oil percentage and compounds composition. The highest and lowest essential oil contents were obtained in plants in substrates containing 30 % of vermicompost and unwashed spent mushroom compost respectively. The main components of essential oil were carvacrol and gamma-trepenine. The highest level of carvacrol (62.10) and gamma-trepenine (32.05) were obtained in plants in substrates containing 40 and 20% of washed spent mushroom respectively

Growth, physiological, and biochemical responses of thyme (Thymus vulgaris L.) to the application of arbuscular mycorrhizal fungi under cadmium stress conditions

Thyme (Thymus vulgaris L.) is one of the most important medicinal plants used in various pharmaceutical, osmotic, health, and food industries. Arbuscular mycorrhizal fungi (AMF) symbiosis is viewed as one of the several methods to improve growth under heavy metals stress. To investigate the effects of cadmium (Cd) and AMF bio-fertilizers on the growth and morpho-physiological characteristics of thyme, a greenhouse experiment was performed in three replications. Experimental treatments included Cd at three levels 0, 75, and 150 mg/kg of soil and AMF at three levels without inoculation, inoculation with Funneliformis etunicatum, and Funneliformis mosseae. Cadmium stressed plant showed reduced plant height, number of leaves, stem fresh and dry weight, and root fresh and dry weight while AMF inoculation enhanced the increased means of these traits considerably. Inoculation with F. mosseae also ameliorated the Cd stress (150 mg/kg) induced reduction in plant height, number of leaves, and stem and root dry weight by 13.41%, 8.42%, 30.3%, and 22.2%, respectively. Cadmium stress reduced membrane stability index while AMF inoculation enhanced membrane stability index considerably. An increase in soluble carbohydrate and proline content was observed due to Cd stress and AMF inoculation caused a further increase in these two metabolite contents ensuring better growth under Cd stressed conditions. Results indicated that F. mosseae had a higher efficiency in increasing morphological traits and improving physiological characteristics than F. etunicatum. Overall, AMF inoculation, especially F. mosseae significant ameliorative potential for Cd toxicity in thyme plants

Antioxidant Compounds of Potato Breeding Genotypes and Commercial Cultivars with Yellow, Light Yellow, and White Flesh in Iran

Potatoes are a staple food with high antioxidant properties that can positively affect population health. The beneficial effects of potatoes have been attributed to tuber quality. However, the tuber quality related researches at genetic levels are very few. Sexual hybridization is a powerful strategy for producing new and valuable genotypes with high quality. In this study, 42 breeding potato genotypes in Iran were selected based on appearance characteristics such as shape, size, color, eyes of tubers, and tuber yield and marketability. The tubers were evaluated for their nutritional value and properties, viz. phenolic content, flavonoids, carotenoids, vitamins, sugars, proteins, and antioxidant activity. Potato tubers with white flesh and colored skin had significantly higher levels of ascorbic acid and total sugar. The result showed that higher phenolic, flavonoid, carotenoid, protein concentration, and antioxidant activity were noted in yellow-fleshed. Burren (yellow-fleshed) tubers had more antioxidant capacity in comparison to genotypes and cultivars, which did not differ significantly with genotypes 58, 68, 67 (light yellow), 26, 22, and 12 (white). The highest correlation coefficients in antioxidant compounds were related to total phenol content and FRAP, suggesting that phenolics might be crucial predictors of antioxidant activities. The concentration of antioxidant compounds in the breeding genotypes was higher than in some commercial cultivars, and higher antioxidant compounds content and activity were detected in yellow-fleshed cultivars. Based on current results, understanding the relationship between antioxidant compounds and the antioxidant activity of potatoes could be very helpful in potato breeding projects

Effect of foliar application of selenium on morphological and physiological indices of savory (Satureja hortensis) under cadmium stress

Cadmium is a heavy metal that pollutes the environment and affects plants physiologically and morphologically. Selenium is considered as a beneficial element, with effective roles in increasing plant tolerance to environmental stresses. A greenhouse factorial pot experiment was conducted to study the impact of selenium on traits of Savory plants under Cd stress. Experimental factors included soil contamination with cadmium (0, 75, 100, and 150 μM) and foliar spraying of selenium (0, 10, 20, and 40 μM of Sodium Selenate). Biomass, photosynthetic pigments including chlorophyll a, chlorophyll b, total chlorophyll, proline, total soluble solids, cell membrane leakage, relative water content of leaves antioxidant enzymes, and Cd and Zn concentration in shoot and root were recorded. Results revealed that Cd stress decreased vegetative growth criteria, photosynthetic pigments include chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid almost, 55%, 57%, 57%, and 68%, respectively, while poline, cell membrane leakage, peroxidase (POD), and catalase (CAT) antioxidant enzymes were increased with increasing Cd concentrations. Foliar spray of selenium reduced the toxic effects of Cd stress on savory plants via enhancing of proline content and stimulation of CAT and POD enzymes and limitation of cell membrane leakage. Also, selenium foliar spray improved chlorophyll content under Cd stress condition and decreased cadmium accumulation 29% in root, respectively. In general, these results suggest that foliar application of selenium could mitigate Cd toxicity and improve growth and antioxidant capacity of savory under different level of cadmium heavy metal stress

Evaluation of freezing tolerance in chickpea promising genotypes (Cicer arietinum) using physiological traits and molecular markers

Chickpea is one of the most important plants of the legume family and is very important in the diet. In order to investigate the genetic diversity of chickpea, an experiment was conducted with 18 chickpea genotypes in the form of a completely to investigate the genetic diversity of chickpea, an experiment was conducted with 18 chickpea genotypes in the form of a completely randomized block design. After acclimatization of plants to cold, freezing treatment was applied at temperatures of -6, -8 and -10 and their 50% lethality temperature (LT50) was determined by probit transformation. Before and after the habituation stage, a leaf sample was taken and the relative content of leaf water, photosynthetic pigments, proline, soluble sugar, protein percentage, catalase, peroxidase, polyphenol oxidase and greenness index were measured. Genotype number 5 with the lowest LT50 (-8.86) and the highest survival percentage (80%) was the most resistant genotype and genotype 10 with the highest LT50 (-3.57) and the lowest survival percentage along with genotype 15 were recognized as the most sensitive genotypes. In order to evaluate genetic diversity, DNA extraction was utilized and 21 different ISSR primers were used in the investigation. The results showed the presence of polymorphism among the cultivars studied. A total of 101 clear bands were produced, of which 94 were polymorphic bands. Polymorphic information content (PIC) was in the range of 0.332 (initiator 7) to 0.049 (initiator 16). The amount of gene diversity was between 0.126 and 0.977 changes. Cluster analysis of genotypes was done using Jaccard similarity coefficient and UPGMA metho

Salt Stress Mitigation via the Foliar Application of Chitosan-Functionalized Selenium and Anatase Titanium Dioxide Nanoparticles in Stevia (Stevia rebaudiana Bertoni)

High salt levels are one of the significant and major limiting factors on crop yield and productivity. Out of the available attempts made against high salt levels, engineered nanoparticles (NPs) have been widely employed and considered as effective strategies in this regard. Of these NPs, titanium dioxide nanoparticles (TiO2 NPs) and selenium functionalized using chitosan nanoparticles (Cs–Se NPs) were applied for a quite number of plants, but their potential roles for alleviating the adverse effects of salinity on stevia remains unclear. Stevia (Stevia rebaudiana Bertoni) is one of the reputed medicinal plants due to their diterpenoid steviol glycosides (stevioside and rebaudioside A). For this reason, the current study was designed to investigate the potential of TiO2 NPs (0, 100 and 200 mg L−1) and Cs–Se NPs (0, 10 and 20 mg L−1) to alleviate salt stress (0, 50 and 100 mM NaCl) in stevia. The findings of the study revealed that salinity decreased the growth and photosynthetic traits but resulted in substantial cell damage through increasing H2O2 and MDA content, as well as electrolyte leakage (EL). However, the application of TiO2 NPs (100 mg L−1) and Cs–Se NPs (20 mg L−1) increased the growth, photosynthetic performance and activity of antioxidant enzymes, and decreased the contents of H2O2, MDA and EL under the saline conditions. In addition to the enhanced growth and physiological performance of the plant, the essential oil content was also increased with the treatments of TiO2 (100 mg L−1) and Cs–Se NPs (20 mg L−1). In addition, the tested NPs treatments increased the concentration of stevioside (in the non-saline condition and under salinity stress) and rebaudioside A (under the salinity conditions) in stevia plants. Overall, the current findings suggest that especially 100 mg L−1 TiO2 NPs and 20 mg L−1 Cs–Se could be considered as promising agents in combating high levels of salinity in the case of stevia

Chitosan–Selenium Nanoparticle (Cs–Se NP) Foliar Spray Alleviates Salt Stress in Bitter Melon

Salt stress severely reduces growth and yield of plants. Considering the positive effects of selenium (Se) and chitosan (Cs) separately against abiotic stress, in these experiments, we synthesized chitosan–selenium nanoparticles (Cs–Se NPs) and investigated their ability to reduce the negative effects of salt stress on growth and some biochemical parameters of bitter melon (Momordica charantia). Bitter melon plants were grown at three NaCl salinity levels (0, 50, and 100 mM) and a foliar spray of Cs–Se NPs (0, 10, and 20 mg L−1) was applied. Some key morphological, biochemical, and physiological parameters in leaf samples and essential oil from fruit were measured at harvest. Salinity decreased growth and yield while foliar application of Cs–Se NPs increased these critical parameters. Furthermore, Cs–Se NPs enhanced bitter melon tolerance to salinity by increasing antioxidant enzyme activity, proline concentration, relative water content, and K+, and decreasing MDA and H2O2 oxidants and Na aggregation in plant tissues. Yield was also improved, as the highest amount of essential oils was produced by plants treated with Cs–Se NPs. Generally, the greatest improvement in measured parameters under saline conditions was obtained by treating plants with 20 mg L−1 Cs–Se NPs, which significantly increased salinity tolerance in bitter melon plants

Exogenous melatonin increases salt tolerance in bitter melon by regulating ionic balance, antioxidant system and secondary metabolism-related genes

Melatonin is a multi-functional molecule widely employed in order to mitigate abiotic stress factors, in general and salt stress in particular. Even though previous reports revealed that melatonin could exhibit roles in promoting seed germination and protecting plants during various developmental stages of several plant species under salt stress, no reports are available with respect to the regulatory acts of melatonin on the physiological and biochemical status as well as the expression levels of defense- and secondary metabolism-related related transcripts in bitter melon subjected to the salt stress