Herbal
Seyedeh Zeynab Sharifsadat; Mahnaz Aghdasi; Faezeh Ghanati; Mohammad Hossein Arzanesh
Abstract
Introduction: Azospirillum is the nitrogen fixing microorganisms which improves the growth and development of cereals and other gramineae plants in association with their roots. The goal of present study was to investigate the effect of Azospirillum irakense inoculation in combinations with or without ...
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Introduction: Azospirillum is the nitrogen fixing microorganisms which improves the growth and development of cereals and other gramineae plants in association with their roots. The goal of present study was to investigate the effect of Azospirillum irakense inoculation in combinations with or without auxin (IAA) and/or gibberellin (GA3) treatment on the growth and biochemical parameters of rice (Oryza sative cv. hashemi) seedlings, as well as observing the bacterial colonization process in the root cells. Methods: The roots of 21-days-old rice seedlings were treated with different concentrations (0, 100, 200 ppm) of IAA and/or GA3 for 4 weeks after inoculation with Azosprillum. Result & discussion: The process of bacterial colonization involves the formation of a biofilm, disintegration of the wall, entry of bacteria into root parenchymal cells and development of isolated and scattered colonies. Dry and fresh weight of roots and aerial parts, total dry and fresh weight, and relative growth rate was significantly increased after inoculation with bacteria. The highest level of these parameters was obtained in the seedlings which inoculated with bacteria in combinations with IAA plus GA3 treatment. Meanwhile, the amount of hydrogen peroxide in the roots, soluble protein, soluble sugar and phosphorus was significantly increased in both roots and aerial parts of seedlings after inoculation with bacteria in combinations with IAA plus GA3 treatment, compared to the control. Conclusion: According to the current results, the application of Azospirillum irakense in combinations with IAA and GA3 treatment is a powerful strategy to improve rice seedlings growth
