The Beneficial Effects of Inoculation with Selected Nodule-Associated PGPR on White Lupin Are Comparable to Those of Inoculation with Symbiotic Rhizobia

Nodule endophytes and associated bacteria are non-symbiotic bacteria that colonize legume nodules. They accompany nodulating rhizobia and can form beneficial associations, as some of them are plant growth-promoting rhizobacteria (PGPR) that are able to promote germination and plant growth and increa...

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Detalhes bibliográficos
Autores: Msaddak, Abdelhakim, Quiñones, Miguel Angel, Mars, Mohamed, Pueyo, José Javier
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/341574
Acesso em linha:http://hdl.handle.net/10261/341574
Access Level:acceso abierto
Palavra-chave:Lupin
Lupinus albus
Rhizobia
Bradyrhizobium
Plant growth-promoting rhizobacteria (PGPR)
Nodule
Endophytes
Descrição
Resumo:Nodule endophytes and associated bacteria are non-symbiotic bacteria that colonize legume nodules. They accompany nodulating rhizobia and can form beneficial associations, as some of them are plant growth-promoting rhizobacteria (PGPR) that are able to promote germination and plant growth and increase tolerance to biotic and abiotic stress. White lupin (Lupinus albus) is a legume crop that is gaining relevance as a suitable alternative to soybean as a plant protein source. Eleven nodule-associated bacteria were isolated from white lupin nodules grown in a Tunisian soil. They belonged to the genera Rhizobium, Ensifer, Pseudomonas and Bacillus. Their plant growth-promoting (PGP) and enzymatic activities were tested in vitro. Strains Pseudomonas sp., L1 and L12, displayed most PGP activities tested, and were selected for in planta assays. Inoculation with strains L1 or L12 increased seed germination and had the same positive effects on all plant growth parameters as did inoculation with symbiotic Bradyrhizobium canariense, with no significant differences among treatments. Inoculation with efficient nitrogen-fixing rhizobia must compete with rhizobia present in the soil that sometimes nodulate efficiently but fix nitrogen poorly, leading to a low response to inoculation. In such cases, inoculation with highly effective PGPR might represent a feasible alternative to boost crop productivity.