mohsen azarnia; abbas biabani; Abdollatif Gholizadeh; Hamid Reza Eisvand; Ebrahim Gholamalipour Alamdari
Abstract
Introduction: The most important problems of farmers in arid and semi-arid regions are adequate nutrition, optimum rooting, emergence, establishment and optimal density, and ultimately plant yield. Using grain priming and mycorrhizal inoculation is effective strategies in these conditions. Priming can ...
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Introduction: The most important problems of farmers in arid and semi-arid regions are adequate nutrition, optimum rooting, emergence, establishment and optimal density, and ultimately plant yield. Using grain priming and mycorrhizal inoculation is effective strategies in these conditions. Priming can cause earlier growth of seedling, to increase emergence rate, emergence percentage, plant tolerance to drought and salinity stress, early flowering as well as to increase the quality and quantity of yield and nutrient absorption. Plant hormones such as salicylic acid and gibberellic acid can be used for priming. Regarding plant response to environmental stresses, salicylic acid, which is an important signal molecule, plays a key role in the regulation of several physiological processes such as growth and plant development, absorption of ions, emergence and photosynthesis. Gibberellic acid (GA3) has been shown to be involved in many physiological processes such as cell division activity of meristem regions, increase the cell length, emergence speed, and emergence percentage, seedling growth in field condition, early flowering and yield. Mycorrhizal inoculation increases the availability of nutrients especially plant phosphorus, concentrations of plant hormones (auxins, cytokinins and gibberellins), chlorophyll content, the efficiency of biological nitrogen fixation, assimilates allocation to host plant organs, the changes of root structure, and improve soil structure.
Materials and Methods: In order to evaluate the response of lentil to grain priming (without grain priming, hydro-priming, 100 ppm gibberellic acid, 100 ppm salicylic acid, 100 ppm gibberellic acid + 100 ppm salicylic acid) and soil mycorrhizal inoculation (non-inoculated control, inoculated with Glomus moseae and Glomus intraradices), a factorial experiment based on a completely randomized block design with four replications carried out in a greenhouse and research farm of the Gonbad Kavous University during 2013 and 2014. Various priming treatments - applied in the laboratory. Then, during planting, mycorrhizal inoculation treatment was kept in the closet place to the grains about 5 g per gram of grain (40 spores per gram). To determine the activity of roots (root length and number of nitrogen fixation nodes) 10 seedlings per pot were kept. Measured traits in the field condition were included the concentration and uptake of total phosphorus in aerial parts, concentration and total phosphorus uptake of grain, grain yield, and biological yield.
Results and Discussion: Variance analysis showed that different treatments of mycorrhizal inoculation, priming, and their interactions had significant effects on the studied traits such as the root length, number of nitrogen fixation nodules, phosphorus concentration of aerial parts, grain phosphorus concentration, grain phosphorus uptake, biological yield, and grain yield. In this study the highest root length (39.5 cm), nitrogen fixation nodules (114), aerial parts phosphorus uptake (12.1 kg/h) were obtained under combined treatment of G. intraradices inoculation+ 100 ppm gibberellic acid. While the aerial parts phosphorus concentration (0.24%) and grain phosphorus uptake (22.8 kg/ha) were higher due to using combined treatment of mycorrhizal G. Moseae + hydro-priming. Hormonal priming with salicylic acid increased grain yield and biological yield significantly over the other hormonal priming and control. Hydro-priming had a significant and positive effect on grain yield in three levels of bio-fertilizer. Results of salicylic acid treatment were similar to the results of hydropriming. Influence of hormones, especially gibberellic acid in grain causes more activities in some emergence catalytic enzymes, the emergence speed, emergence percentage and root elongation. These effects may be inconspicuous in irrigated cultivation, but it can lead to the survival of plants in the dry farming situation. In this study, gibberellins increased the radicle length and the number of nitrogen fixation nodules. It may be an important factor in increasing the quality and quantity of grain yield of lentil. Various treatments of salicylic acid had a moderate effect. More positive effects were obtained when these treatments applied to the form of combination. The most applied treatments in this experiment such as mycorrhizal and priming treatments and their interaction had a positive effect on quality and quantity of grain properties of lentil aerial parts. This positive effect may be due to availability of some nutrients which is supplied using priming treatments, microorganisms, secretion of growth promotion and the change of root structure.
Conclusion: In the present study inoculation of both fungi and various treatments of priming had a positive effect on the studied traits individually, but the higher effects of them were found in the combined treatments. The effect of G. intraradices + hydro-priming was more outstanding. Overall, the present study indicated that the various treatments of bio-fertilizer and priming increased the root length and nitrogen fixation. Therefore, the absorption of nutrients was increased. It could be concluded that synthesis fertilizer is unnecessary.