ISOLATION OF ENDOPHYTIC BACTERIA FROM THE AERIAL PART OF POLYGONUM AVICULARE

Abstract

Endophytic microorganisms affect plant growth, development and productivity due to the synthesis of various phytohormones, and also contribute to the conversion of insoluble mineral salts into a form accessible to plants. Endophytic bacteria are microorganisms that colonize the internal tissues of plants without causing diseases in them. They inhabit the intercellular spaces and inside the cells, promoting plant growth, increasing their resistance to stresses (drought, salinity) and protecting them from pathogens.To isolate strains of endophytic bacteria, root samples were thoroughly washed with distilled water in order to remove surface contamination. After washing, the samples were immersed for 5 minutes in a 70% ethanol solution and for 1 minute in a 0.1% solution of mercuric chloride (HgCl₂), and then washed with sterilized water to remove sterilizing agents. To prepare the initial homogenate solution, 5 g of root sample tissue were homogenized in 50 ml of distilled water. The obtained homogenate solution was inoculated by the method of sequential serial dilutions into Petri dishes with nutrient agar. To control the quality of surface sterilization of the sample, 100 µl of the liquid from the last washing was inoculated into a dish with nutrient agar.