Bradyrhizobium spp. Strains in Symbiosis with Pigeon Pea cv. Fava-Larga under Greenhouse and Field Conditions

Abstract

ABSTRACT:Optimization of symbiosis between nitrogen-fixing bacteria and legumes has been extensively studied, seeking agricultural sustainability. To evaluate the symbiotic efficiency of nitrogen-fixing bacterial strains belonging to the Bradyrhizobium genus with pigeon pea (Cajanus cajan (L.) Millsp.) cv. Fava-Larga, experiments were conducted in Leonard jars (axenic conditions), pots with soil, and in the field. Ten strains were tested in Leonard jars, and three strains, in addition to BR 29, were selected according to their ability to promote the growth of pigeon pea, for further tests in pots with different soil types (Inceptsol and Oxisol) and in the field (Oxisol). Treatments were compared with strains BR 2003 and BR 2801 (approved as inoculants for pigeon pea), with a non-inoculated control with mineral N fertilization, and with another non-inoculated control (absolute control) with low mineral N concentration (Leonard jars) or without mineral N fertilization (soil). The efficiency of Bradyrhizobium strains in axenic conditions varies among strains, being higher when pigeon pea cv. Fava-Larga establishes symbiosis with the strains UFLA 03-320, UFLA 03-321, UFLA 04-212, BR 2801, and BR 2003. The soil type influences the symbiotic efficiency of Bradyrhizobium-pigeon pea in soil in the greenhouse, mainly in Inceptsol, in which strains UFLA 04-212, BR 2801, and BR 2003 increased N accumulation in the plant. The strain UFLA 03-320 increased shoot dry matter and N accumulation in the shoot equivalent to the mineral N treatment under field conditions. UFLA 03-320, BR 29, UFLA 03-321, and UFLA 04-212 promoted yields similar to those of the reference strain (BR 2801), and of the mineral N treatment with 70 kg ha -1 urea-N. These results confirm that pigeon pea establishes efficient symbiosis, which provides the N required for its growth. All strains, except for BR 2003, show potential for recommendation as inoculants for grain production. The strain UFLA 03-320 also shows potential for use in green manure crops.

Influence of Plant Growth Promoting Rhizobium on Growth of Pigeon Pea [Cajanus cajan (L.) Millsp.]

“…Lowest total dry matter production was recorded in T 7 (4.73 g/plant). The results are in line with the findings of Rufini et al (2016) observed the symbiosis of Bradyrhizobium sp. with pigeon pea Cv.…”

Estudo Da Consorciação De Práticas Agropecuárias Para O Desenvolvimento De Sistemas Sustentáveis E Eficientes Na Produção De Ovinos De Corte / Consortium Study of Agricultural Practices for the Development of Sustainable and Efficient Systems in the Production of Beef Sheep

“…Esse é um processo muito importante para as plantas, o qual consiste na redução do nitrogênio atmosfera (N2) à amônia (NH3) no solo podendo ser utilizado pelas plantas para inúmeras funções (RUFINI et al, 2016).…”

“…Estirpes de Bradyrhizobium (bactéria fixadora de nitrogênio) são desenvolvidas em laboratório para serem inoculadas nas sementes, momentos antes da semeadura viabilizando o aumento do processo (EMBRAPA CERRADO, 2016;DE CARVALHO et al, 2017). Rufini et al (RUFINI et al, 2016) realizaram uma pesquisa para avaliar a otimização da relação simbiótica da bactéria do gênero Bradyrhizobium com seis variedades de feijão-guandu (Cajanus cajan) cultivar IAC Fava-Larga, sobre dois tipos de solo (latossolo e Inceptisol). Esses autores concluíram que, cinco das seis variedades avaliadas apresentam potencial para contribuir para o aumento da produtividade de grão em lavoura em sistema de integração, e que a variedade UFLA 03-320 tem potencial para ser usado como adubo verde.…”

Influence of Molybdenum doses in inoculation and mineral fertilization in cowpea beans

“…To supply the need for N, some farmers have decreased the use of mineral fertilization, replacing it with atmospheric N-fixing bacteria. In the process of mutual symbiosis between bacteria and leguminous plants (in this case, Bradyrhizobium), the biological nitrogen fixation (BNF) is considered a key technique to provide N to plants (COOPER; SCHERER, 2012), especially regarding tropical legumes (CASTRO et al, 2017;COSTA et al, 2017aCOSTA et al, , 2017bFERREIRA et al, 2013;LIMA;PEREIRA;MOREIRA, 2005;RUFINI et al, 2016).…”