نشریه روابط خاک و گیاه
پیاپی 53 (بهار 1402)

To investigate the effect of ten species of mycorrhizal fungi belonging to seven different genera (Racocetra, Rhizophagus, Claroideoglomus, Funneliformis, Diversispora, Acaulospora and Gigaspora) on some growth and biochemical traits of fenugreek (Trigonella foenum-groecum), a pot experiment based on a completely randomized design was conducted in the research greenhouse of Ferdowsi University of Mashhad. The changes of biomass, number and length of pods, weight of 1000 seeds, photosynthetic pigments, phenolic compounds, soluble carbohydrates, total protein, and antioxidant capacity in fenugreek plants in response to mycorrhizal inoculation were studied. The results of variance analysis of the data showed that the effect of mycorrhizal fungi on all studied traits was significant at the probability level of 1%. Based on the findings, the response of fenugreek plant to inoculation with different species of mycorrhizal fungi was variable. Inoculation with suitable species of mycorrhizal fungi through improving the growth condition and biochemical traits of treated plants increased the fenugreek growth based on plant fresh and dry weights. In the present study, mycorrhizal species, especially R. castanea, A. langula, R. intraradicese, and G. margarita enhanced the amount of chlorophyll and the activities of antioxidant enzymes of inoculated fenugreek plant compared to the control, which was accompanied by increasing the plant growth in terms of fresh and dry weights in these treatments. According to the obtained results, inoculation of fenugreek plant with C. claroideum, R. castanea, A. langula, G. margarita, R. fasciculatus, and F. caledonium fungi can be suggested as a suitable alternative for chemical fertilizers to increase the yield of this plant.

Accumulation of heavy metals in medicinal plants can have dangerous consequences for human health. This study investigates the concentration of heavy metals including zinc, lead, copper, and cadmium in the soil, aerial parts (shoot), and roots of the medicinal plants Phlomis olivieri Benth. and Stachys inflata Benth. around the Zeh-Abad lead and zinc mine in Qazvin province. The soil and plant samples were collected and prepared, and the total concentrations of heavy metals in the samples were measured by an atomic absorption spectroscopy in three replicates. The results showed that, unlike copper and cadmium, the concentrations of lead and zinc in the soil, shoot, and roots of the studied plants were several times greater than the standards (i.e., EPA and WHO). The average concentrations of zinc and lead in the contaminated soil were 1791 and 2855 mg/kg, respectively. The average concentrations of zinc and lead in the roots of Ph. olivieri were 394 and 56 mg/kg, respectively, and in the shoot of this plant were 442 and 76 mg/kg, in the roots of S. inflata, were 452 and 38 mg/kg, and in the shoot of this plant were 501 and 68 mg/kg, respectively. The highest concentration of zinc was measured in the root of S. inflata (i.e. 694 mg/kg) and the highest concentration of lead was determined in the shoot of Ph. olivieri (i.e. 140 mg/kg). The transfer factor values for the lead and zinc in both plants were higher than one; in the case of the copper and cadmium, its values were lower than one. Considering the harvesting of these two medicinal plants by the native people in the region, the results of this study can be a warning for the health of these people.

Little information is available concerning ionic composition of the suitable nutrient solution for fodder maize production in soilless culture. Therefore, the aim of this study was to select a basic nutrient solution for production of fodder maize in soilless culture. A pot experiment was carried out as a factorial in a randomized complete block design with two factors of nutrient solutions and cultivar types and four replications in the research greenhouse of Shahrekord University. The nutrient solutions were: 1) full-strength Hoagland and Arnon, 2) half-strength Hoagland and Arnon, 3) Barry and Miller, 4) Alexander et al., and 5) Ruakura. Two maize cultivars of single cross hybrid 704 and single cross 410 were used. The results indicated that in both maize cultivars, the highest concentrations of nitrogen and phosphorus in leaf, stem and root were observed in the plants nourished with Ruakura nutrient solution. The application of Alexander et al. nutrient solution led to significant increase in potassium concentrations in leaf, stem, and root compared to other nutrient solutions. Optimum supply of nutrient requirements of maize with Ruakura nutrient solution resulted in significant increase in plant height, stem diameter, leaf area and leaf greenness index. In both maize cultivars, the highest shoot fresh and dry weights as well as water use efficiency were obtained in the plants nourished with Ruakura nutrient solution. Based on the results, application of Ruakura nutrient solution is suggested for the cultivation of both maize cultivars (i.e., single cross hybrid 704 and single cross 410) in soilless culture in order to produce fodder under the conditions similar to this study.

The large area of saline soils in Iran and decreasing in quality of these soils require that the effectiveness of conservation tillage systems in such lands be investigated. This project aims to determine changes in soil physical properties in three different types of tillage system and plant residue management, including: 1) conventional tillage system and removal of crop residues from soil surface, 2) reduced tillage system and preservation of crop residues, and 3) no tillage system and preservation of crop residues in rotation of barley and safflower in a saline soil with irrigation water salinity of 5.35 dS/m for four years. Some soil physical properties such as bulk density and porosity, and aggregate stability indices of mean weight diameter (MWD) and geometric mean diameter (GMD) were measured in soil samples prepared from the layers of 0-10, 10-20 and 20-30 cm. After each crop rotation period, water infiltration into the soil was measured and the modified Kostiakov model was fitted to obtain the optimized parameters. The results of variance analysis of the data in the four years of the experiment showed that the difference in most of the soil properties at the end of the experiment was significant due to the tillage treatments compared to the control. The highest MWD and GMD (2.53 and 1.90 mm, respectively), porosity (51.2%) and final infiltration rate (31 cm/h) were observed in the no-tillage system. while the lowest MWD and GMD (2.02 and 1.29 mm, respectively), porosity (47.8%) and final infiltration rate (3.5 cm/h) were recorded in the conventional tillage system. Overall, our findings showed that the increment in the soil organic matter due to the implementation of conservational tillage treatments improved the stability of soil aggregates and increased soil porosity and water infiltration into the soil.

To investigate the response of transplant and whole plants of tomato (Solanum lycopersicum) to the type of substrate and fertilizer, a factorial experiment was conducted as a randomized block design in Minab city of Hormozgan province with three replications. The first factor included four types of substrates and the second factor included five fertilizers levels. The results of the greenhouse experiment showed that the substrate type and fertilizer had a significant effect on the transplant traits. The results showed that the maximum leaf number and root dry weight of transplants were obtained in the cocopeat + vermicompost substrate. In each substrate, fertilizers improved the transplant traits, and organic and biological fertilizers were more effective. Thus, the maximum transplant height was determined in the cocopeat + vermicompost with algae fertilizer, and the maximum fresh weight and root volume were measured in the same substrate but with phosphozite fertilizer. The results of the field study showed that the evaluated traits were affected by the substrate type and fertilizer, and the seedlings previously grown in the substrates that improved their traits, had better growth after transferring to the field. The results showed that the highest number and yield of fruit, total soluble solids, and ascorbic acid were obtained in the seedlings produced in cocopeat + vermicompost substrate and organic fertilizers.

In this research, the effect of plant growth-promoting rhizobacteria, Bacillus pumilus, and Zhihengliuella halotolerans, on the morpho-physiological traits of Nitraria schoberi under the influence of dust (control and 1.5 g/m2/month) was investigated. The results showed that dust had a negative effect on the morphological and physiological traits of the plant. Dust caused a decrease of 20, 15, 17 and 20% in chlorophyll a, carotenoid, total soluble protein, and total dry biomass and an increase in the total flavonoids, total phenol content, total antioxidant capacity and glycine betaine amounting to 107, 32, 15 and 10 percents, respectively. Both bacteria improved the condition of the plant against stress, so that B. pumilus and Z. halotolerans increased the amount of chlorophyll b by 13 and 21%, protein by 27 and 43%, and total biomass by 60 and 27%, respectively. In this experiment, the role of B. pumilus strain was more than that of Z. halotolerans strain, so that B. pumilus strain alone had the greatest effect in increasing chlorophyll a and seedling quality index by 52 and 108%, respectively. The results showed that B. pumilus and Z. halotolerans strains can increase the resistance of the Nitraria schoberi to dust stress and help us to stabilize salty dusts in playas.