Effect of arbuscular mycorrhizal fungi on growth, mineral nutrition and nitrogen fixation of three varieties of common beans (Phaseolus vulgaris)

Abstract

SUMMARYA pot experiment was conducted under glasshouse conditions to investigate the effect of inoculation with four arbuscular mycorrhizal (AM) fungi {Glomus clarum, G. etunicatum, G. manihotis, Gigaspora margarita), either individually or in a mixture, and wdth Rhizobium leguminosarum hiovar phaseoli, on the growth, mineral nutrition, and contribution of biologically fixed Ng, to three nodulating bean {Phaseolus vulgaris) varieties (Carioca, Negro Argel and Rio Tibagi). The ^^N isotope dilution technique and three control crops (non-nodulating bean, Panicum maximum and sorghum) were used to quantify the contribution of Ng fixation. There were significant differences between the capacity of the different AM fungi to infect and colonize the roots of the different bean varieties. Inoculation with AM fungi significantly increased production of dry matter by 8-23 % and the concentration of P in plants by 160-335%. A strongly positive correlation of % root colonization by AM fungi and plant P concentration and accumulation was observed which suggests that the observed inoculation responses were a result of improved P acquisition by the mycorrhizal roots. N derived from the atmosphere increased significantly with AM fungi inoculation, with Carioca showing the best response, followed by Negro Argel and Rio Tibagi, thereby showing the indirect and positive effect of AM fungi inoculation on the Ng-fixing association between Rhizobium and Phaseolus vulgaris.

Effect of two AMF life strategies on the tripartite symbiosis with Bradyrhizobium japonicum and soybean

“…It has been assumed that the significance of the tripartite symbiosis is solely associated with increased P supply to the nodules through the AMF (e.g. Ganry et al 1982;Kawai and Yamamoto 1986;Vejsadová et al 1993;George et al 1995;Ibijbijen et al 1996;Xavier and Germida 2003). However, a number of studies have suggested that signalling mechanisms regulate the early interaction between the three symbionts (e.g.…”

From production to consumption: tracing C, N, and S dynamics in Brazilian agroecosystems using stable isotopes

“…Moreover, biotic factors -such as the absence of indigenous rhizobia or arbuscular mycorrhizal fungi (Ibijbijen et al, 1996) -and legume genotype can also affect legume symbiotic dependence. A comprehensive review of this subject was published by Chalk et al (2006).…”

Differences in Arbuscular Mycorrhizal Fungi among Three Coffee Cultivars in Puerto Rico

“…Variation among cultivars and genotypes in dependence on AM fungi has been found in many crop plants [2,3,[31][32][33][34][35]. Breeding and selection programs often include fertilization regimes that might be expected to select against ability to form mycorrhizae [5,6].…”