Potential Application of Glomus Intraradices (AMF) and Different Isolates of PGPR (Biotol) to Enhance the Yield and Quality of Wheat Grown in The Field in Calcareous Soil Under Different Salinity Levels

Abstract

Two field experiments were carried out at the farm of Nubaria Agricultural Research Station during the two winter seasons of 2012/2013 and 2013/2014, to study the effect of the arbuscular mycorrhizal fungus, Glomus intraradices and the plant growth promoting rhizobacteria (Biotol) on growth, yield parameters and chemical contents of two wheat cultivars (Sakha 93 and Gemmeza 9) grown in calcareous soil under four levels of soil salinity and four rates of NPK mineral fertilizers. Results indicated that, wheat plants inoculated with AMF and Biotol together significantly decreased Na shoot content (mg/kg), increased NPK uptake, proline and salicylic acid contents, chlorophyll and grain protein at all the tested salinity levels compared to uninoculated plants. Under normal salinity level (≤4 dSm -1), dual inoculation with AMF and Biotol resulted total grain yield to 6.5 and 6.7 t/ha for Sakha 93 and Gemmeza 9, respectively, in the presence of NPK100% with a percentage increases of 41 and 29 more than un-inoculated plants. Results clearly indicated that, proline and Salicylic acid content were significantly increased in dual inoculated plants in Sakha 93 comparing to Gemmeza 9 under soil salinity up to 8 dSm -1 . The percentage increases were 38.6 and 37.54 for proline and 192.57 and 135.42 for salicylic acid in case of Sakha 93 and Gemmeza 9, respectively, in the presence of NPK75% and soil salinity 8-12 dSm -1 . No significant differences were observed among plants inoculated with G. intraradices and PGPR either in the presence of 75 or 100% of the recommended dose of NPK. Summing up it could be concluded that inoculation with AMF and Biotol successfully improve the growth, yield and salt stress tolerance of the tested cultivars in calcareous soil.

Signals and Machinery for Mycorrhizae and Cereal and Oilseed Interactions towards Improved Tolerance to Environmental Stresses

“…AMF promote the reduction in Na + and Cl − ions uptake, contributing to maintaining vacuolar membrane stability and facilitating the sequestration of Na + into plants’ vacuoles. This mechanism has been reported in several cereal crops, including wheat [ 58 , 59 ], maize [ 56 , 60 , 61 , 62 ], rice [ 63 , 64 , 65 ], and sorghum [ 63 , 66 , 67 ]. Selvakumar et al [ 61 ] found higher K + /Na + and ZmAKT2 (a phloem-expressing K + channel), ZmSOS1 (with ability to extrude Na + and control xylem loading for a long-distance Na + transport), and ZmSKOR (involved in the translocation of K + towards shoots through xylem) gene expression in maize root inoculated with Gigaspora margarita or Claroideoglomus lamellosum .…”