مجله آب و خاک (Feb 2016)
Changes in Nutrient Content of Root and Grain of Wheat Cultivars Inoculated by Azospirillum and Mycorrhiza
Abstract
Introduction: Providing the nutritional requirements of agricultural crops by non-chemical resources is a new approach in the organic farming that has attracted the attention of both the researchers and the consumers in recent years. Therefore, it is highly important to find new fertilizer resources that are both economically able to provide the nutritional needs of the crop plants and have no adverse effects on the consumers and the environment. Materials and Methods: With this approach, an experiment was conducted in the research station of Shahid Chamran University of Ahvaz, Iran in 2012-13. The experimental design was factorial based on randomized complete blocks design with three replications. The treatments including Mycorrhizal fungi in three levels (i.e. no use of strain; use of Glomus intraradices strain; and use of Glomus mosseae strain), bacteria Azospirillum lipoferum in two-levels (i.e. non-inoculated and inoculated) and wheat cultivars in three levels (i.e. Chamran; Dena; and Behrang). The measured parameters include the concentration of macronutrients (i.e. nitrogen, phosphorus and potassium) and some micronutrients (i.e. zinc, iron and manganese) in two part seed and the root of wheat. Results and Discussion: Surveying the elements content in the root and the grain indicated a significant and positive effect of the use the Azospirillum and Mycorrhiza to improve the concentration of the elements in wheat cultivars. However, the simultaneous use of these microorganisms led to an increase of the effects of their application on their assessed traits.Finally the highest concentration of N (2.21 present), P (0.50 present) and Fe (33.88 mg.kg-1) were observed in the grain; the highest concentration of K (0.93 present and 0.54 present) and Mn (43.11 and 23.63 mg.kg-1) were observed in the grain and root, respectively. Moreover, the highest concentration of Zn in the root (19.70 mg.kg-1) was obtained from inoculation of C.V Dena seeds with Azospirillum and the use of G. mosseae. Also, in the general case of Mycorrhiza fungi use (between 6 to 20 present) and seed inoculation with Azospirillum lipoferum (between 8 to 25 present), the improved nutrient content in the seeds as well as greatest impact of Mycorrhiza use is in increasing the content of the grain Zn (20 present) and the lowest effect of Mycorrhiza using is in increasing the nitrogen content in seed (6 percent). Considering the elements content in the grain, the use of bacteria also showed that the greatest impact on increasing the use of bacteria Azospirillum lipoferum is in increasing the iron content in seeds (25 present) and the least impact of the use of Azospirillum lipoferum is in increasing the seed’s manganese (8 present). Moreover, the use of Mycorrhiza fungi (between 7 and 23 present) and seed inoculation with Azospirillum lipoferum (4 to 16 present) improved the contents of nutrients in wheat roots compared with the control group. Here, too, the greatest impact for Mycorrhiza application was in increasing the content of the Zn in the root (23 present) and the lowest effect of Mycorrhiza application was in increasing the potassium content in the root (7 percent). Moreover, considering the elements content in the roots in the case of being treated with Azospirillum lipoferum, the results showed that upon increasing the use of bacteria, the greatest impact of Azospirillum lipoferum in increasing elements content in the roots was an increased iron content in the root (16 present) and the minimum effect of the bactericidal application was in increasing the potassium root (4 present). Comparing the two species of Mycorrhizal fungi that have been used in the experiment, although application Glomus intraradices showed satisfactory results, the use of the species Glomus mosseae to increase the content of the element in seeds and roots has had a greater role. Moreover, the combined effects of these microorganisms have not only had an antagonistic effect of reducing the amount of content, they have also been more effective than being applied separately (between 7 and 12 present). Conclusion: Generally associated with most of the measured elements, the treatment of seed inoculation with Azospirillum lipoferum and usage of Glomus mosseae in Dena cultivar that was a durum wheat, showed the highest concentration of the mentioned elements in the roots and seeds. Probably this has been due to the smaller grains in Dena than the other cultivars, which led to an increase in the ratio of the elements in the grain. Therefore, it seems that the use of the biofertilizers can be the perfect solution to eliminate the nutritional requirements of wheat. Moreover, it has the very important effect of the enrichment of this crucial product in the people’s dietary patterns in this country with the required elements. Keywords: Azospirillum, Nutrition, Wheat, Root, Elements concentration, Mycorrhiza
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