Effect of Growth Promoting Fungi on Morphological and Physiological Properties of Sesame in Drought Condition
Javad Shafiey Jazy
Published: December 30, 2021
Abstract
Drought has been recognized as a primary constraint in limiting the growth and development of plants. It impairs normal growth, disturbs water relations, and reduces water use efficiency in plants. Drought stress at any growth stage also, poses detrimental effects on morphological and physiological criteria in plants. To maintain growth and productivity, plants must adapt to stress conditions and exercise specific tolerance mechanisms of stress agents. Plant modification for enhanced tolerance is mostly based on gene transformation, however, the nature of the genetically complex mechanisms of abiotic stress tolerance, and the potential detrimental side effects, make this task extremely difficult. A promising alternative for improving plant drought tolerance is using the beneficial soil microorganisms including Plant-growth-promoting fungi (PGPF). This research was undertaken to investigate the effect of two PGPFs on some morphological and physiological indices and nutritional status of sesame plant under drought conditions. For this purpose, a field experiment using a completely randomized blocks with three replications and treatments including fungal inoculation (non-inoculation, Piriformospora indica and Rhizophagus irregularis) and drought levels include 55, 75 and 85% of SAW (Soil Available water) depletion on the basis of combined analysis in Lavark Field (Isfahan Province) was conducted. The results showed that the comparison of studied fungi indicates that only R. irregularis increased the concentration of phosphorus in the shoot part of plants, significantly. Each of the studied fungi showed their positive effect on different characteristics and also different drought stresses. So that, R. irregularis increased phosphorus content at 75% of SAW depletion, relative water content of leaf and nitrogen content at 85% of SAW depletion and catalase activity, membrane stability, iron concentration, shoot biomass and number of leaves at 75% and 85% of SAW depletion. However, P. indica increased iron concentration and height of shoot at 75% of SAW depletion, shoot biomass and nitrogen content at 85% of SAW depletion and catalase activity, membrane stability, relative water content of leaf and number of leaves at 75% and 85% of SAW depletion. The studied fungi increased the activity of catalase enzyme in all drought treatments. In general, the obtained results of this research indicate that drought is a limiting factor for plants, and PGPFs can improve plant tolerance to this environmental stress by improving plant nutritional status, water content and activity of anti-oxidant enzymes.
Keywords: Drought; Plant Growth promoting fungi (PGPFs) and Sesame