Title:	Genetic diversity and symbiotic efficiency of pigeonpea rhizobia from the Brazilian drylands.
Authors:	SANTOS, J. W. M. dos MARIN, A. M. P. RIBEIRO, P. R. de A. FREITAS, A. D. S. de SILVA, V. S. L. MORAES, S. A. de MARTINS, L. M. V. FERNANDES JUNIOR, P. I.
Affiliation:	JONNATHAN WHINY MORAES DOS SANTOS, UNIVERSIDADE FEDERAL DA PARAÍBA; ALDRIN MARTIN PÉREZ MARIN, INSTITUTO NACIONAL DO SEMIÁRIDO; PAULA ROSE DE ALMEIDA RIBEIRO, UNIVERSIDADE DO ESTADO DA BAHIA; ANA DOLORES SANTIAGO DE FREITAS, UNIVERSIDADE FEDERAL RURAL DE PERNAMBUCO; VIVIANE SIQUEIRA LIMA SILVA, CPATSA; SALETE ALVES DE MORAES, CPATSA; LINDETE MÍRIA VIEIRA MARTINS, UNIVERSIDADE DO ESTADO DA BAHIA; PAULO IVAN FERNANDES JUNIOR, CPATSA.
Date Issued:	2025
Citation:	Pesquisa Agropecuária Tropical, v. 55, e83256, 2025.
Description:	The pigeonpea (Cajanus cajan) crop has a high potential for sustainable agricultural systems in semiarid regions due to its robustness, multifunctionality, and ability to perform biological nitrogen fixation in symbiosis with rhizobia. This study aimed to isolate and characterize native rhizobia at the molecular and symbiotic levels from pigeonpea root nodules cultivated in soils of the Brazilian drylands. A total of 19 bacterial isolates were obtained, 12 of which amplified the symbiotic nifH and nodC genes, which were subjected to Box-PCR fingerprinting and 16S rRNA gene sequencing. The isolates were classified into the Bradyrhizobium, Rhizobium, and Agrobacterium genera, with a notable genetic diversity observed even among samples from the same region. In a completely randomized greenhouse experiment under gnotobiotic conditions, 11 out of the 12 isolates exhibited symbiotic efficiency comparable to that of the commercial strain Bradyrhizobium pachyrhizi BR 2003 in at least one of the evaluated parameters (shoot dry biomass, number of nodules per plant, and N accumulation). The results indicate the presence of promising native rhizobia for use in inoculants adapted to the conditions of the Brazilian semiarid region, particularly the strains ESA 769, ESA 770, ESA 775, ESA 776, and ESA 777. Additionally, the presence of Agrobacterium strains capable of forming functional nodules in pigeonpea suggests the occurrence of horizontal gene transfer of symbiotic genes.
Thesagro:	Cajanus Cajan Rhizobium Guandu
NAL Thesaurus:	Bradyrhizobium Agrobacterium
Keywords:	Pigeonpea Fixação biológica de nitrogênio Diversidade genetica Semiárido Rizóbios nativos Biodiversidade do solo Feijão guandu
ISSN:	1983-4063
Type of Material:	Artigo de periódico
Access:	openAccess
Appears in Collections:	Artigo em periódico indexado (CPATSA)