Effect of Application of Different Fertilizer Sources on Physiological and Biochemical Traits of new Cultivars of Barley under Dryland Conditions

Mycorrhiza fungus is of special importance in organic agriculture and in relation to the coexistence of all root characteristics of the host plant is affected and also improves the water relationship in the host plant.  With application of mycorrhizal fungus, the plant absorbs soil water better and as a result, by increasing the relative moisture content of the leaves, the stomata are open for a longer time and carbon dioxide processing is done optimally, resulting in more photosynthesis, which ultimately leads to increased yield. The aim of this research in rainfed agriculture is to reduce the stresses on rainfed wheat. In rainfed wheat cultivation, the plant gets its water requirement from rainfall. In most cases, the plant water needs are not met in this way. Due to the reduction of grain yield of rain-fed barley cultivars, new achievements can be reached by investigating the role of plant growth-promoting bacteria on physiological and biochemical traits under rain-fed conditions. Considering that no research has been reported on the role of plant growth promoting bacteria on rainfed barley in the country and especially in Ilam province. Therefore, the present experiment was conducted to investigate the effect of plant growth promoting bacteria on the activity of antioxidant enzymes and physiological traits of rain-fed barley cultivars.
Materials and

In order to investigate the effect of inoculation with mycorrhizal fungi on some physiologic and biochemicaltraits of barley cultivars in rainfed conditions, a factorial field experiment was carried out in the form of a randomized complete block design with three replications in the farm station of Sarablah Agricultural Research Center during 2019-2020 cropping season. Experimental treatments including factor of barley cultivars (Mahali, Mahour, Khoram and Fardan) and fertilizer sources treatment including: control (without fertilizer source), 50% P fertilizer, mycorrhizal fungus (Glomus mosseae, Glomus etunicatum and Rhizophagus irregularis), mycorrhizal fungi + 50% P chemical fertilizer and 100% P chemical fertilizer.
Results and

The results of this experiment showed that the interaction between cultivar×fertilizer sources had a significant effect on the activity of some antioxidant enzymes and physiological properties. Fardan cultivar× mycorrhizal fungi +50% P chemical fertilizer increases the activities of ascorbate peroxidase (14.3 µmolmin-1 mg protein-1), gluthathion peroxidase (3.5 µmol.min-1 .mg protein-1), catalase (12.1 µmolmin-1 .mg protein-1), peroxidase (14.8 µmol.min-1 .mg protein-1), super oxid dismutas (25.4 µmol.min-1 .mg protein-1), chlorophyll a (3.5 mg.g-1 fresh weight), chlorophyll b (3.3 mg.g-1 fresh weight) and reduces malonde aldeyede (20.4 nmol.g fresh weigh leaf) and hydrogen Peroxide (0.26 mmol.g-1 FW) and Mahali cultivar× control treatment (without fertilizer sources) had the lowest activities of ascorbate peroxidase, peroxidase, superoxide dismutase and photosynthetic pigments.

The results of this study showed that in the dryland conditions of the region, physiological traits (leaf chlorophyll content) were significantly reduced in all studied barley cultivars. In this study, the maximum activity of hydrogen peroxide and malondealdeyede in the Mahali cultivar×control treatment was observed, but when inoculation was used with mycorrhizal fungus, observed an increase in physiological characteristics. Fardan cultivar×Mycorrhiza+50% P fertilizer with maximum activity of photosynthetic pigments and antioxidant enzymes (superoxide desmutase, catalase and peroxidase) which resulted in increased growth and yield. According to the results of this study, among the rainfed barley cultivars used, Fardan cultivar with mycorrhizal fungi +50% P fertilizer can be recommended in rainfed agriculture of the region.

Acknowledgements

This research was derived from a research project that was carried out at Sarablah Agricultural Research Station. Thanks to all the colleagues who accompanied and helped the authors during the implementation of this study.