Development and activity of the symbiosis between Bradyrhizobium strains, Glomus species and Cicer arietinum: effect of timing of inoculation and photon irradiance
Year: 1994
Type: article
Abstract: The compatibility of dual inoculation of Glomus species and Bradyrhizobium strains was determined in relation to the time of inoculation and light intensity. The effects of simultaneous or sequential inoculation of two arbuscular mycorrhizal fungi, Glomus mosseae or Glomus fasciculatum and two Bradyrhizobium strains (Br 185 or Br 192) on the growth and nutrient uptake by Cicer arietinum were evaluated. Plant development depended on the particular combination of Bradyrhizobium strain and Glomus species. Symbiotic efficiency was also influenced by the relative time of inoculation of the endophytes involved. Prior inoculation with the mycorrhizal fungus was usually the most effective. Colonization by mycorrhizal fungi was negatively affected when fungi were applied to the seedlings after inoculation with Bradyrhizobium. Nodule number, however, was not increased by prior inoculation with bradyrhizobia. A crucial factor determining the lack of successful nodulation by Br 192 in plants colonized by G. fasciculatum ( the most infective AM endophyte) was found to be a low level of photosynthetic activity. Symbiotic efficiency (plant growth and nutrition) also decreased when the photosynthetic capability of the plants was not sufficient to respond to the demand of the endophytes regarding G. fasciculatum, which was not the case with G. mosseae treatments. Reduction of light intensity to 81.3 µE s-1m-2 (PAR), particularly affected plants colonized by G. fasciculatum as determined by the total sugar content of root extracts. Nearly stressed levels showed higher competitive ability of Glomus species than those of Bradyrhizobium strains, the most sensitive microsymbiont to plant colonization under these limited C resources. Glomus species were less affected and extensive AM colonization reduced the spread of nodulation. The fact that G. mosseae can maintain its activity under stressed light conditions is important in relation to the selection of AM endophytes to be used with leguminous plants.
Authors: Juan Manuel Ruíz-Lozano, Rosario Azcón
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W2502043095