Symbiosis effects of Mycorrhizal and Pseudomonas on morphophysiological traits of mung bean (Vigna radiata (L.) Wilczek) under moisture stressed condition

IntroductionEnvironmental stresses especially drought are important and effective factors reducing plant production. Mung bean (Vigna radiata (L) Wilczek) from leguminosae family mostly grows in tropical areas and has a lower water requirement compared to other legumes. The role of mycorrhizal symbiosis to protect plants under drought conditions is considerable. The main effects of drought stress at the flowering stage are aborting flowers and eventually declining seed yield while the major effects of drought stress are on reproductive organs of plants in the pod filling stage. Therefore, effects of drought stress occurring due to lack of water are in different growth stages which can be divided into flowering and pod filling stages. The aim of this study was to improve some morphophysiological traits, nitrogen, protein, root colonization, mycorrhizal dependency and mycorrhizal growth response percentage of mung bean by Glomus mosseae and Pseudomonas fluorescence strain 169 symbiosis under different imposed moisture stress conditions. Materials and MethodsA split plot Randomized Complete Block Design experiment with three replications was conducted in the research farm of Islamic Azad University of Miyaneh branch, Iran, during 2016. The main factors allocated to three levels of drought stress included: normal irrigation (control), stopping irrigation in flowering stage, stopping irrigation in pods formation stage. Sub-factor was considered for four treatments of inoculation including: non-inoculation (control), inoculation by G. mosseae, P. fluorescens strain169 and G. mosseae+P. fluorescens strain169. Parto variety of mung bean (Vigna radiata L. Wilczek) used in this study was provided by Seed and Plant improvement Institute, Karaj, Iran. Suspension solutions of Pseudomonas fluorescens strain169 with 108-109 live and active bacteria per ml (CFUml-1) were provided by Water and Soil Research Institute, Karaj, Iran. Glomus mosseae was obtained from Zist Fanavaraneh Turan biotech firm, which had approximately 30 live fungi per gram and was produced by culturing in host plants, used in the form of soil mixed spores and hyphae. Inoculation of seeds by Pseudomonas fluorescence strain 169 was done in the morning by mixing them in an aluminum paper. The 2% glucose solution was added to increase the number of bacteria attached to seeds, and the seeds were then allowed to be dried in shadow. In order to increase the efficiency of fungi and bacteria in sowing time, s