Effects of Nano Chelated Zinc and Mycorrhizal Fungi Inoculation on Some Agronomic and Physiological Characteristics of Safflower (Carthamus tinctorius L.) under Drought Stress Conditions

IntroductionZinc is an essential element for plants and animals and plays an important role in plants metabolic system. This element activates enzymes and involved in protein, lipids, carbohydrates and nucleic acid metabolism. Zinc has a major role in cell defenses against ROS and as a protective factor against several chemical compositions of oxidation such as membrane lipids, protein, chlorophyll, and enzyme having sulfhydryl and DNA. Zinc is an essential micronutrient that plays many important roles in various physiological and metabolic processes in all living organisms. It functions as a cofactor for over 300 enzymes and proteins involved in cell division, nucleic acid metabolism and protein synthesis.
Nanoparticles have received considerable attention due to their increased uptake and high rate of penetration in plants. Nanomaterials are classified as materials with at least one dimension less than 100 nm. Nonmaterial could to be applied in designing more soluble and diffusible sources of Zn fertilizer for increased plant productivity.
Safflower (Carthamus tinctorius L.) an oilseed crop is a member of the family Compositae or Asteraceae. Safflower, a multipurpose crop that has been grown for centuries in India for the orange-red dye (carthamin) extracted from its brilliantly colored flowers and for its quality oil rich in polyunsaturated fatty acids (linoleic acid, 78%). Safflower flowers are known to have many medicinal properties for curing several chronic diseases, and they are widely used in Chinese herbal preparations.
The mycorrhizal symbiosis is arguably the most important symbiosis on earth. The majority of these mycorrhizal interactions is mutually beneficial for both partners and is characterized by a bidirectional exchange of resources across the mycorrhizal interface. The mycorrhizal fungus provides the host plant with nutrients, such as phosphate and nitrogen, and increases the abiotic (drought, salinity and heavy metals) and biotic (root pathogens) stress resistance of the host.
Materials and MethodsIn order to evaluate the effects of nano-zinc fertilizer and mycorrhizal fungi symbiosis on some agronomic and physiological characteristics of safflower (Carthamus tinctorius L.) under drought stress conditions, an experiment was arranged as split plot based on randomized complete block design with three replications at the Agricultural Research Station, West Azarbaijan Province, Naghadeh city during growing season of 2013-2014. The main factor consisted of four irrigation levels (irrigation after 60, 110, 160 and 210 mm evaporation from pan) and sub factor included four fertilizer levels (nano fertilizer, mycorrhizal, mycorrhizal鶩 fertilizer and control). Studied traits were number of head per plant, number of seed per head, 1000-seed weight, biological yield, seed yield, oil percentage, soluble sugars and proline contents.
For statistical analysis, analysis of variance (ANOVA) and Duncan’s multiple range test (DMRT) were performed using SAS version 9.9 (SAS Institute Inc., Cary, NC, USA).
Results and DiscussionThe results declared that increasing drought stress decreased yield and yield components (such as number of head per plant, number of seed per head and 1000-seed weight) significantly. But, application of fertilizer sources decreased the drought effects, so in irrigation levels, application of nano fertilizer, mycorrhizal and mycorrhizal鶩 fertilizer increased these traits. The highest seed yield (2588 kg.ha-1) was obtained in irrigation after 60 mm evaporation of pan with using mycorrhizal鶩 fertilizer and the lowest amount (1836.6 kg.ha-1) from irrigation after 210 mm evaporation of pan and control. Oil percentage decreased by increasing drought stress, but oil percentage with application of mycorrhizal鶩 fertilizer significantly increased (11%) compared to control (without application fertilizers). Increasing drought stress and use of nano zinc fertilizer and mycorrhizal symbiosis, increased significantly soluble sugars and proline contents. Elicitation of results showed that inoculation of mycorrhizal under water stress conditions could be increase water and nutrients uptake by increasing uptake of root and could improve plant tolerance against to drought stress. On the other hand, given the role of zinc in plants in drought stress conditions, the existence enough amount of this nutrient is effective to adjust consistency.
ConclusionsThe results of the study showed that the application of Nano chelated zinc fertilizer and mycorrhizal fungi had significant improvements on some physiological characteristics of safflower beside, yield and yield components also increased. Because of more zinc uptake and symbiosis with mycorrhizal fungi, water and minerals uptake increased thus decreased negative effects of drought stress. Due to global attention to sustainable agriculture, environment and human health, nanotechnology and biofertilizers can be as alternative fertilization methods. According to recent years conditions as decline in groundwater, reduce rainfall and water shortages, revising oilseeds nutritional management is necessary.