Effect of Indole Acetic Acid on the Synergistic Interactions ofBradyrhizobiumandGlomus fasciculatumon Growth, Nodulation, and Nitrogen Fixation ofDalbergia sissooRoxb

Abstract

The legume Dalbergia sissoo Roxb is an important forest tree of the arid and semiarid regions. The efficiency of Bradyrhizobium (Ds Rhz-9) and Glomus fasciculatum (Thaxter sensu Gerd.) Gerd. and Trappe to promote growth of D. sissoo and the effect of indole acetic acid (IAA) on the tripartite symbiotic association was studied in a pot experiment. Parameters like plant growth, nodulation, total phosphorus, total nitrogen content, nitrogenase activity of root nodules (acetylene reduction assay), and arbuscular mycorrhizal fungi (AMF) root colonization were analyzed. The dual inoculation of Bradyrhizobium along with G. fasciculatum showed synergistic increase in growth, nodulation, and nitrogen fixation of the seedlings. The maximum nitrogen (1.45%) and phosphorus (34.6%) content of dry weight was recorded in the dual inoculated plants when treated with IAA (1.39 Â 10 À3 mole=liter). The nitrogenase activity of the nodules in dual treatments showed an enhancement of 34.9%, which became further enhanced by 15.7% when treated with IAA. The presence of Bradyrhizobium in the rhizosphere was found to decrease AMF root colonization. In dual inoculated plants, the exogenous application of IAA (1.11 Â 10 À3 moles=liter) increased AMF root colonization by 60%. The tripartite synergistic interaction of Bradyrhizobium and G. fasciculatum with D. sissoo seems to be promising and can be utilized for its growth promotion in forest nurseries and reforestation of degraded areas. Exogenous application of IAA will be beneficial and recommended.

The interactive effects of plant microbial symbionts: a review and meta-analysis

“…However, two studies found that AM fungal colonization decreased in the presence of rhizobia, but Jia et al (2004) also demonstrated that the photosynthetic rate was higher in plants infected with both symbionts concurrently. Similarly, Niranjan et al (2007) found that while AM fungal colonization decreased with rhizobia, nitrogen fixation was higher in the presence of both symbionts. While many of the interactions were positive, they were not usually synergistic (but see Pacovsky et al 1986;Ferrari and Wall 2008), as plants often did not perform better than expected given symbiont individual effects.…”

Mycorrhiza-Induced Resistance and Priming of Plant Defenses

“…A positive effect of mycorrhization on beneficial plant-microbe interactions has been noted. For example, promotion of the interaction or synergistic effects have been described with regard to plant associations with nitrogen-fixing bacteria (Jia et al, 2004;Niranjan et al, 2007;Ferrari and Wall, 2008;Larimer et al, 2010); phosphatesolubilizing bacteria (Toro et al, 1996;Belimov et al, 1999;Kohler et al, 2007); biocontrol agents (Haggag and Abd-El Latif, 2001;Martínez-Medina et al, 2009;Martínez-Medina et al, 2010;Saldajeno and Hyakumachi, 2011); and plant growth-promoting microorganisms (Meyer and Linderman, 1986;Chandanie et al, 2005Chandanie et al, , 2006Chandanie et al, , 2009.…”

Performance Analysis and Soil Quality Indexing for Dalbergia sissoo Roxb. Grown in Marginal and Degraded Land of Eastern Uttar Pradesh, India

“…Moreover, the plant is well suited to grow under extreme conditions like contaminated, degraded and marginal lands. [31][32][33]. The biomass production and carbon sequestration potential of D. sissoo has been analyzed in the Tarai region of Central Himalaya [33].…”

“…Another study suggested that five-years aged coppice shoots of the Dalbergia plantation on sodic land produced aboveground biomass of 13.52 Mg ha −1 [26] with the maximum proportion in the stem-wood (9.84 Mg ha −1 ), followed by branch-wood (2.92 Mg ha −1 ) and leaf (0.78 Mg ha −1 ). Furthermore, Singh et al [30] reported luxurious growth of D. sissoo on sodic land in northern India with higher fuelwood properties, including a wood density of 0.73 g cm −3 , and an FVI of 777 [30] Previous studies have also proved that Dalbergia plantations can improve soil properties like nitrogen, phosphorus and potassium content [34], and different methods have been employed to enhance the growth of the plant [31].…”