Avaliação da inoculação de bactérias diazotróficas na emergência e desenvolvimento de plantas.

Abstract

Humans and plants have a close relationship with bacteria. The beneficial interaction between plants of the families Fabaceae and Poaceae and diazotrophic bacteria has been widely studied, due to the capacity that these bacteria have to promote better plant development through the mediation of several chemical reactions such as biological nitrogen fixation, phosphate solubilization and production of plant hormones. The present work aimed to verify if diazotrophic bacteria are able to influence plants belonging to other families from germination to development. Plants of tomato (Solanaceae), butter cabbage (Brassicasseae) and cucumber (Cucurbitaceae) were planted in autoclaved sand and then inoculated with six types of bacteria from soils of Ceará, Maranhão and Piauí. Each plant presented 180 samples, of which, 120 inoculated and 60 non-inoculated. Each bacterium was inoculated on 20 samples from each plant. Cucumber seedlings were harvested on day 21 and cabbage and tomato seedlings on day 42. It was found that the bacteria did not promote higher percentage of plant emergence, however, the bacteria PI04, PI12 and CE32 obtained the best results having effect on the increase of leaf and root area length and on the obtainment of dry mass in leaves and roots. Thus, these bacteria have the potential to be used as inoculants.