title: Variability in colonization of arbuscular mycorrhizal fungi and its effect on mycorrhizal dependency of improved and unimproved soybean cultivars.
abstract: Breeding selection of germplasm under fertilized conditions may reduce the frequency of genes that promote mycorrhizal associations. This study was developed to compare variability in mycorrhizal colonization and its effect on mycorrhizal dependency (MD) in improved soybean genotypes (I-1 and I-2) with differential tolerance to drought stress, and in unimproved soybean genotypes (UI-3 and UI-4). As inoculum, a mixed native arbuscular mycorrhizal fungi (AMF) was isolated from soybean roots, showing spores mostly of the species Funneliformis mosseae. At 20 days, unimproved genotypes followed by I-2, showed an increase in arbuscule formation, but not in I-1. At 40 days, mycorrhizal plants showed an increase in nodulation, this effect being more evident in unimproved genotypes. Mycorrhizal dependency, evaluated as growth and biochemical parameters from oxidative stress was increased in unimproved and I-2 since 20 days, whereas in I-1, MD increased at 40 days. We cannot distinguish significant differences in AMF colonization and MD between unimproved and I-2. However, variability among improved genotypes was observed. Our results suggest that selection for improved soybean genotypes with good and rapid AMF colonization, particularly high arbuscule/hyphae ratio could be a useful strategy for the development of genotypes that optimize AMF contribution to cropping systems.
authors: a Instituto Nacional de Tecnología Agropecuaria (INTA) Centro de Investigación Agropecuaria (CIAP), Instituto de Fisiología y Recursos Genéticos Vegetales (IFRGV) Camino 60 Cuadras km, 51/2 Córdoba C.P. 5119, Argentina.
authors: M S
authors: MS
authors: Salloum
authors: a Instituto Nacional de Tecnología Agropecuaria (INTA) Centro de Investigación Agropecuaria (CIAP), Instituto de Fisiología y Recursos Genéticos Vegetales (IFRGV) Camino 60 Cuadras km, 51/2 Córdoba C.P. 5119, Argentina.
authors: M C
authors: MC
authors: Guzzo
authors: b Instituto Spegazzini, La Plata C.P. B1900AVJ, Argentina.
authors: M S
authors: MS
authors: Velazquez
authors: a Instituto Nacional de Tecnología Agropecuaria (INTA) Centro de Investigación Agropecuaria (CIAP), Instituto de Fisiología y Recursos Genéticos Vegetales (IFRGV) Camino 60 Cuadras km, 51/2 Córdoba C.P. 5119, Argentina.
authors: M B
authors: MB
authors: Sagadin
authors: a Instituto Nacional de Tecnología Agropecuaria (INTA) Centro de Investigación Agropecuaria (CIAP), Instituto de Fisiología y Recursos Genéticos Vegetales (IFRGV) Camino 60 Cuadras km, 51/2 Córdoba C.P. 5119, Argentina.
authors: C M
authors: CM
authors: Luna
mesh_terms: D055864:Droughts; D005838:Genotype; D055137:Glomeromycota / Q000254:growth & development / Q000502:physiology*; D038821:Mycorrhizae / Q000254:growth & development / Q000502:physiology*; D018384:Oxidative Stress; D055170:Plant Root Nodulation; D018517:Plant Roots / Q000382:microbiology / Q000502:physiology; D012641:Selection, Genetic; D013025:Glycine max / Q000235:genetics / Q000382:microbiology* / Q000502:physiology; D013312:Stress, Physiological; D013559:Symbiosis
keywords: Glomeromycota; arbuscular mycorrhizal fungi (AMF); dépendance mycorhizienne; génotypes améliorés et non améliorés; improved and unimproved genotypes; mycorhizes arbusculaires (MA); mycorrhizal dependency; oxidative stress; stress oxydatif