Fixação biológica de nitrogênio em feijão-comum (Phaseolus vulgaris L.)

Abstract

The common bean (Phaseolus vulgaris L.) considered one of the most important grains for human consumption. Is a source of proteins, vitamins, and minerals, constituting a safety factor and food and nutritional security. Brazil stands out as the third largest producer of common bean in the world and the State of Paraná has the largest national production. Nitrogen is one of the most demanded essential elements for the development of plants, it makes up the chlorophyll molecule, constitutes amino acids and participates in vital processes such as photosynthesis and respiration. The biological fixation of atmospheric nitrogen by cultivated plants from symbiosis with bacteria is improved using inoculants and constitutes an important way to meet the demand for nitrogen, especially in a scenario in which there is a search for the adoption of practices aimed at increasing the sustainability of agricultural systems. However, most studies indicate that biological nitrogen fixation in bean crops is not as efficient, due to factors related to cultivars, bacterial strains and environmental conditions. Aiming to present an overview of the studies carried out about biological nitrogen fixation in common beans, the objective of the work was to carry out a survey of data from scientific publications using a bibliometric approach. Data were collected from the Web of Science database and analyzed using the bibliometrix package of the Rstudio software. It was observed that the year 2018 had the hight of publications on the subject, but that there has been a decrease in the number of publications since then. The main theme studied was the genetic diversity of symbiotic rhizobia that nodulate common bean with a view to seeking new strains with potential for inoculation. Brazil stands out as the country with the highest number of citations and publications on the topic and where 5 of the 10 institutions with the greatest relevance on the topic are located, based on the total number of publications by affiliated authors. Despite the importance of biological nitrogen fixation in common bean and the increase in the number of publications and studies carried out over the period analyzed (1991-2021), knowledge on the subject is still incipient and the main challenges faced for the isolation of new strains with potential for use in inoculants are related to the presence of very competitive native strains in the soil, the symbiosis capacity of common bean with a wide diversity of rhizobia and the environmental conditions that affect biological nitrogen fixation, such as high temperature, acidity and low soil humidity.