03042naa a2200337 a 450000100080000000500110000800800410001902200140006010000250007424501280009926000090022752020540023665000260229065000210231665000160233765000160235365000140236965000370238365000130242065000150243365300360244870000170248470000170250170000170251870000200253570000200255570000150257570000220259070000190261277300730263121861102026-04-07       2026    bl uuuu     u00u1 u    #d  a0718-95161 aRIBEIRO, N. V. da S.  aNovel diazotrophic bacterial strains to enhance biomass and nutrient uptake in brachiaria genotypes.h[electronic resource]  c2026  aABSTRACT - Brachiaria grasses dominate Brazilian pastures, yet studies on their association with diazotrophic bacteria are limited. Here, we examined the growth-promoting effects of eight bacterial strains per Brachiaria genotype (eleven genotypes in total), selected from a working culture collection of 32 strains, in a soil box experiment. Subsequently, five strains were evaluated under field conditions with three B. brizantha genotypes (Marandu, Paiaguás and Xaraés) to identify potential biofertilizer candidates. Methods: Both experiments were conducted using a completely randomized block design, with three and four replications, respectively. In the greenhouse, each Brachiaria genotype, analysed independently, consisted of 10 treatments: an uninoculated control, nitrogen fertilizer, and eight bacterial strains while the field experiment included eight treatments: five strains (greenhouse study), a commercial inoculant, nitrogen fertilizer, and an uninoculated control. In the greenhouse experiment, shoots were harvested at 2, 4, and 6 months after cutting and subsequently regrowth. In the field experiment, plants were harvested at 4, 7, 10, and 13 months under the same growth cycle. Total dry biomass and nutrient uptake (nitrogen, phosphorus, and potassium) were analysed for each harvest in both experiments. The box experi- ment revealed that inoculated Brachiaria plants exhibited higher biomass production and NPK nutrient uptake compared to the absolute control. Notable increases included up to 23% in dry biomass, 37% in total N, 24% in total K, and 32% in total P, varying by strain and genotype. In the field, the Paiaguás genotype showed a significant response to Azospirillum argentinense strains NRB085 and NRB214, with statistically superior increases in dry biomass and NPK uptake compared to the control. The findings indicate that strains NRB085 and NRB214 exhibit good biofertilizer potential, positioning these A. argentinense strains as promising inoculant candidates for improving Brachiaria pasturelands  aBacterial communities  aGrowth promotion  aPseudomonas  aRhizobiales  aSymbiosis  aVesicular arbuscular mycorrhizae  aBiomassa  aInoculante  aPlant growth promoting bacteria1 aARRUDA, G. M1 aVIDAL, M. S.1 aALVES, G. C.1 aROUWS, J. R. C.1 aJESUS, E. da C.1 aSCHWAB, S.1 aBARRIOS, S. C. L.1 aBALDANI, J. I.  tJournal of Soil Science and Plant Nutritiongv. 26, p.952-970, 2026.