Isolamento de rizóbios de nódulos de Phaseolus vulgaris cultivado em duas regiões de Alagoas

ABSTRACT: An important attribute of the common bean is its ability to symbiotically associate with rhizobia, forming nodules, where the process of biological correction of atmospheric nitrogen occurs. The objective was to determine the rhizobia diversity gained from common bean plants collected in fields in two regions of the state of Alagoas: Agreste and Sertao, in the municipalities of Santana do Ipanema and Arapiraca, respectively. Three sowing density were evaluated, being: 60,000, 120,000 and 180,000 plants/hectare, using a completely randomized design with three sowing densities and 6 plots. For the collection of nodules, a circle was demarcated around the plant corresponding to an area of the root system, a circle of approximately 15 cm was used around the plant with a dug depth of 30 cm. Disinfestation was performed in an aseptic chamber, with all solutions, water and material used being previously sterilized. The growth of the Rhizobia colonies was verified daily for 10 days, after the growth as different colonies were raised to another plate with YEM culture medium. The results were discovered at the Tukey test at the 5% level. It was found that the higher the planting density, the greater the number of colonies identified in the plant nodules and that the region of the Alagoas sertao presents greater nodulation capacity compared to an Agreste region. In both areas, acid and alkali formation is observed. In addition, the possibility of the Sertao more diverse morphological specialties, suggesting that the microorganisms of this area have a greater adaptation to the conditions of the studied areas. KEYWORDS: Alagoas; Beans; Atmospheric Nitrogen.