Interactions amongst Mycorrhiza, Azotobacter chroococcum and Root Characteristics of Wheat Varieties

Abstract

A field experiment was conducted in a randomized block design with three replications over 2 years to evaluate the effect of wheat cultivar and dual inoculation of Azotobacter chroococcum (Azc) and arbuscular mycorrhiza fungi (AMF, Glomus fasciculatum) on root characters and AMF infection in three crosses of wheat. The experimental material comprised four wheat parents, WH‐147, WH‐157, WH‐542 and PBW‐175, and three F1 crosses, WH‐147 ×WH‐157, WH‐147 × WH‐542 and WH‐147 × PBW‐175. Comparison of treatment averages, i.e. control (mineral nutrients 60 kg N + 30 kg P2O5 + 12.5 kg ZnSO4 ha−1, as in other two treatments), AMF and AMF + Azc, revealed that inoculation of Azc led to an increase in AMF infection in roots. Maximum root biomass was obtained in F1 hybrids WH‐147 × WH‐157 in the AMF treatment and in WH‐147 × PBW‐175 receiving AMF + Azc. Total root length and AMF infection of roots was maximum in WH‐147 × PBW‐175 for all the treatments during both years. A positive association between AMF infection in roots and Azotobacter survival in the rhizosphere was apparent. Similarly, maximum A. chroococcum counts were observed 80 and 120 days after sowing in the AMF + Azc treatment in cross WH147 × PBW175.

Performance and gene effects for wheat yield under inoculation of arbuscular mycorrhiza fungi and Azotobacter chroococcum

“…Such cross specific beneficial effect on productivity of wheat crop of Azotobacter chroococcum, as a soil inoculant, has also been reported in wheat crop (Narula et al 1998). Manske et al (2000) and Behl et al (2002Behl et al ( , 2003 have also observed synergistic effects between AMF and Azc. The genetic control of peduncle length, flag leaf area, spike length, grain weight, grain yield and biological yield was mainly due to additive effects and bio-inoculants had enhanced the magnitude or significance of these effects.…”

“…The responsiveness of wheat varieties in terms of improved performance of different traits to microbes greatly differs and these differences are due to the genetic background of the varieties (Behl et al 2003). Wheat genotypes having improved root length density (RLD), a large number of spikes per m 2 and seed weight support microbe symbiosis in low input environment (Manske et al 2000).…”

Contribution of Arbuscular Mycorrhizal Fungi (AM Fungi) and Rhizobium Inoculation on Crop Growth and Chemical Properties of Rhizospheric Soils in High Plants

“…The rate of uptake of nutrients by the plants may be limited by its rate of diffusion through the soil .Hyphae of AM fungi, which extend beyond the plant rhizosphere can take up N and transport it into the rooting zone and this can increased uptake of Zn, Mn and Fe in plants due to the inoculation with AM fungus Glomus fasciculatum [28]. According to them promotion of plant growth with the help of mycorrhizal infection may be through direct acquisition of nutrients by the fungus or indirectly by modifying transpiration rates and the composition of rhizosphere microflora.…”

Comparison of the effectiveness of wheat roots colonization by Azotobacter chroococcum and Pantoea agglomerans using serological techniques

“…However, wheat varieties as well as bacterial strains were found to show differences in survival of A. chroococcum (Behl et al 2003, Singh et al 2004, Narula et al 2006. Therefore, plant-microbe interaction studies remain important.…”