پژوهشهای زراعی ایران (Jun 2024)
Effects of Inoculation with Plant Growth Promoting Rhizobacteria and Nanoparticles on the Dry Matter Transfer Process and Yield Triticale (Triticosecale Wittmack) under Irrigation Regimes
Abstract
Introduction Among abiotic stress factors, drought is one of the most detrimental factors in arid and semiarid regions, causing a significant decrease in plant growth and yield in most species, including crops. Under drought conditions, morphological, physiological, and biochemical characteristics are negatively affected. The detrimental impact of water scarcity may be mitigated through the utilization of plant growth-promoting rhizobacteria (PGPR) and nanoparticles (NPs) like nano iron-silicon oxide. PGPR species such as Azospirillum and Pseudomonas have been found to enhance hormonal balance, maintain nutrient levels, improve plant growth characteristics, and ultimately boost yield. Additionally, the application of NPs aids in enhancing plant growth under stressful conditions by facilitating water retention, fortifying membrane integrity, and enhancing nutrient and water uptake. Consequently, it is plausible that the combined application of PGPR and NPs could enhance triticale yield even in conditions of water limitation.Materials and MethodsAn experiment as factorial split-plot was conducted based on randomized complete block design with three replications at the research farm of the Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili in 2021. Different irrigation regimes in three levels (full irrigation as control, irrigation withholding at 50% of booting and heading stages as severe and moderate water limitation respectively (BBCH 43 and 55 codes respectively) were assigned to the main plots and the combination of bio fertilizers application in four levels (no application as control, application of Azospirilum, Pseudomonas, both application Azospirilum and Pseudomonas) and nanoparticles foliar application at four levels (foliar application with water as control, nano iron oxide foliar application (1 g.L-1), nano silicon oxide (50 mg.L-1), both application nano iron-silicon oxide) were assigned to the subplots. Psedomunas and Azospirilum were isolated from the rhizospheres of wheat by the Research Institute of Soil and Water, Tehran, Iran. For inoculation seeds were coated with gum Arabic as an adhesive and rolled into the suspension of bacteria until uniformly coated. The strains and cell densities of microorganisms used as PGPR in this experiment were 1×108 colony forming units (CFU). In each plot, there were five rows with two m long. In each experimental plot, two beside rows and 0.5 m from the beginning and end of planting lines were removed as margin, and measurements were done on three rows in the middle lines. The used nano silicon-iron oxide had an average particle size of less than 30 nm and the special surface of particles was more than 30 m2.g-1. They were product of Nanomaterial US Research which was provided by Pishgaman Nanomaterials Company of Iran. Nano silicon oxide and nano silicon oxide powder added to deionized water and was placed on ultrasonic equipment (100 W and 40 kHz) on a shaker for better solution. Foliar application of nano silicon-iron oxide was done in two stages of period growth BBCH 21 and 30 codes respectively. In this study, dry matter remobilization, volume and root dry weight, leaf area index (LAI), and grain yield of triticale were investigated. Analysis of variance and mean comparisons were performed using SAS ver 9.1. The main effects and interactions were tested using the least significant difference (LSD) test at the 0.05 probability level.Results and Discussion The results showed that remobilization from the stem (22.75%) and total dry matter remobilization (21.36%) and contribution of these processes in grain yield (58.29 and 56.24% respectively) decreased in both application of PGPR and nano iron-silicon oxide foliar application under irrigation withholding at booting stage in compared to no application of bio-fertilizers and nanoparticles. Also, the application of PGPR and nanoparticles under irrigation withholding in the booting stage increased the root volume (44.68%), current photosynthesis (48.63), the contribution of photosynthesis contribution in grain yield (15.63%), LAI (32.82%), and grain yield in compared to no application of PGPR and nanoparticles under irrigation withholding at booting stage.ConclusionBased on the results of this study, it seems that the application of both PGPR and nanoparticles can be a suitable management factor to increase the grain yield of triticale under water-limited conditions.
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