Isolamento e identificação de bactérias endofíticas de raízes de alho e caracterização da promoção de crescimento em meristemas micropropagados

Abstract

Due to the concern to promote a sustainable agriculture, the implantation of technologies with more efficient systems of agricultural production has increased, with ecological approaches and with responsible use of the natural resources. Plant growth promoting bacteria (PGPB) are one of the potential alternatives to achieve this goal. Garlic (Allium sativum L.) is one of the crops whose economic importance has increased considerably in recent years in Brazil, being a source of income for small and large formers. However, garlic needs to be free of viruses for its cultivation, a preponderant factor for the success of its production. Therefore, the use of PGPB is an efficient alternative in reducing costs with agricultural inputs and increases productivity. Thus, the aim of this study was to isolate and evaluate the potential growth promoter of endophytic bacteria of garlic root and bacteria from the Collection of Cultures of Agricultural Microbiology (CCMA – UFLA). In addition, to verify the improvements of the phytotechnical, nutritional and physiological attributes of garlic meristem cultivated in tissue culture under the action of PGPB. Forty-eight endophytic bacteria were identified by the mass spectrometry technique (MALDI-TOF MS) according to its protein profile of each isolate. Four bacteria were selected according to their capacity to produce auxin, to fix biological nitrogen and to solubilize phosphate, and the cultivation of garlic meristem in tissue culture inoculated with these bacteria was established in a population of 10 6 CFU / mL. The capacity of colonization of the bacteria inside garlic plants by scanning electron microscopy and the phytotechnical, anatomical and chlorophyll content of garlic plants in vitro after inoculation of PGPB were also evaluated. With this study, it was possible to improve the phytotechnical, nutritional and physiological characteristics of the garlic from the inoculation of PGPB in vitro. M19B and CCMA 0056 stand out as candidates for application in promoting plant growth.