Survey on Efficiency of inoculation methods of Pseudomonas fluorescens on growth and yield of Thymus kotschyanus
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Ali Salehnia sammak,1,* Mohammad matinizadeh,2 Alireza mohebbi,3
1. Department of Microbiology, Rasht Branch, Islamic Azad University, Rasht, Iran
2. Research Institute of Forests and Rangelands, Agricultural Research,Education and Extension Organization Tehran, Iran
3. School of Medicine, Golestan University of Medical Sciences, Gorgan, Iran
- Introduction: The use of microorganisms as biofertilizers for improve crops and production has been used and being common practice in the last years. Plant growth-promoting rhizobacteria (PGPR) (Kloepper, 1993) has known as biofertilizer because these microorganisms adapt and grow rapidly around plant rizosphers (Ahirwar et al., 2015; Ul Hassan and Bano, 2015). However, some reports indicate that rhizobacteria inhibit the maximum growth of some plants by producing hydrogen cyanide. Research has shown that growth-promoting soil bacteria can increase plant growth and mineral uptake. Facilitate even in stressful situations [6].
Pseudomonas fluorescens can cause of increase the plant's access to absorbable iron in the rhizosphere and subsequently play an important role in improving plant growth in terms of quantity and quality.
they are famous biofertilizers and also through various mechanisms such as stimulating the production of plant hormones such as auxin, cytokine and gibberellin and also inhibiting the production of ethylene, increasing the solubility of inorganic and organic phosphate, producing microbial siderophores to increase plant access to absorbable iron, nitrogen fixation in symbiotic Or non-symbiotic in stimulating and improving plant growth in terms of quantity and quality
- Methods: In this study to investigate Efficiency of various Inoculation Methods of Pseudomonas fluorescens on growth,
characteristics and percentage of essential oil of Thymus kotschyanus, an experiment was conducted in Randomized Complete Block Design with four treatments and three replications at Alborz Research Complex, Research Institute of Forests and Rangelands.
The standard bacterial strain of Pseudomonas fluorescens (R-169) was obtained from the Soil and Water Research Institute.
Method1 :Thymus seeds were placed in a sterile plate. after determining the germination potential, each seed soaked in 5 ml of bacterial liquid suspension of Pseudomonas fluorescence standard strain (P-169) prepared by the Soil and Water Research Institute with a population of 108cfu / ml was added. For better effectiveness, Arabic gum as a carrier was added for seed adhesive. Before inoculation, Bacterial suspension prepared in 108 cfu / ml at room temperature (25 ° C) on a shaker at 120 rpm.Then, after 48 hours of incubation, constant turbidity with absorption of 560 nm was read by spectrophotometry.
Method2: After rooting the seedlings, 50 ml of the bacterial suspension with 108 cfu / ml by sterile syringe in the zone around the root in contact with rhizosphere of the plants were added. The suspension was prepared and the turbidity was fixed as in the first method.
Method 3 Both site inoculation: Bacterial suspension with population of 108 cfu / ml was added by half McFarland method in Erlenmeyer 100 ml with physiological serum in a ratio of 1 to 9 to reach a population of 107 cfu / ml then as in the first method (5 ml per seed) And the second method (50 ml in contact with plant roots) was added.
plants harvested after 3 months from transplanting.
The oil content was estimated by steam distillation using Clevenger’s apparatus.
- Results: In all Inoculation methods, Pseudomonas fluorescence showed, an increase in growth and the amount of essential oil . The effect of inoculation by mixed method (roots and seeds) had a greater effect on morphological traits and growth and percentage of thyme essential oil. The highest amount of root volume with 30 ml compared to the control (15 ml) was significant at the level of 0.5, the highest dry weight of the plant with 24.75 g and the highest number of branches with 25, respectively, compared to the control (20 g and 18 g). Showed no significant difference, and the highest amount of essential oil with 1.74% was obtained in inoculation of Pseudomonas fluorescens in the third method (seeds and roots).
- Conclusion: in this study, inoculation of Pseudomonas fluorescence by liquid suspension method with seeds, roots and rhizosphere of the plant had a positive effect on morphological characteristics and percentage of Thymus kotschyanus essential oil, which had a significant effect on some characteristics. The increased fresh and dry weight and root volume of roots in comparison with control was observed.
the most effective inoculant method was the both inoculation with seed soaking and roots injection in method 3 in compared to inoculation seperately.
- Keywords: Pseudomonas fluorescence, Medicinal Plants, Biofertilizers, Thymus kotschyanus , Bacterial Inoculant
