Seleção e caracterização de bactérias fixadoras de nitrogênio associadas ao feijão-caupi (Vigna unguiculata (L.) Walp).

Abstract

The cowpea (Vigna unguiculata L. Walp) commonly known as Macassar beans, rope beans, black-eyed beans, green beans, or Bahian beans, constitutes as the main subsistence crop of the North and Northeast regions of the country. In addition, it is characterized as one of the main sources of energy and protein in food. The selection of rhizobium isolates tolerant to salinity and temperature stresses, characteristic of the semi-arid region, increases the chances of success for the introduction of bacteria fixing atmospheric nitrogen in association with Vigna unguiculata L. Walp. The objective of this study was to select and characterize morphologically isolated native cowpea from semiarid regions, tolerant to abiotic factors. Microbiological studies were conducted at the Soil Microbiology Research Unit (UPMS), Department of Soils and Rural Engineering (DSER), Center for Agricultural Sciences (CCA), Federal University of Paraíba (UFPB), municipality of Areia, Paraíba. We proceeded the selection of nodules and bacterial isolation, from nodules obtained from cowpea roots, coming from agricultural areas under Entisol with a history of caupi bean cultivation. In vitro tolerance tests were also performed, with different salinity and temperature variations. A parti of the characterization data were obtained 12 isolates plus the recommended. Where 12 showed rapid growth, and of these 10 had the ability to acidify the medium. All isolates were tolerant of Nacl concentrations and different temperatures.