Abstract:
Soybean (Glycine max L.) is a leguminous crop belongs to the Fabaceae family found in East Asia. The protein from soybeans is used in animal feed, as well as in a variety of food and industrial products. It is the oldest and most important crop of the world originated from China and cultivated for more than 5000 years. It has been found to be effective in a variety of conditions, including high blood pressure, diabetes-related illnesses, and many more. Endophytes such as fungi and bacteria are associated with host plant tissues without causing any harmand secrete diverse bioactive compounds to stimulate plant growth. However, there is little information available regarding the endophytic bacteria associated with the soybean plant roots. This study examined the diversity of fourteen endophytic bacteria isolated from soybean root tissues. Morphological and biochemical characterization methods revealed significant variation among the isolates. The majority of isolates displayed smooth colony surfaces, regular shapes, and rod-shaped cells. However, Bacterial Strain-5 and 11 exhibited rough surfaces and irregular shapes, while Bacterial Strain-4 displayed round cell shapes instead of the typical rod morphology. Moreover, the isolates demonstrated diverse pigmentation, with strains showing various shades of white, creamy, light yellow, pinkish red, light orange, yellow, and red. In KOH test, five strains (2, 6, 9, 10, and 13) showed positive reactions to KOH, while the remaining nine strains (1, 3, 4, 5, 7, 8, 11, 12, and 14) showed negative reactions. The catalase test confirmed that six strains (1, 2, 6, 9, 10, and 13) were gram-negative, and the eight strains (3, 4, 5, 7, 8, 11, 12, and 14) were gram-positive. In the gram staining test, ten strains (1, 2, 3, 6, 8, 9, 10, 11, 12, and 13) were gram-negative, while the remaining four strains (4, 5, 7, and 14) were gram-positive. Finally, in the starch hydrolysis test, ten strains (1, 2, 3, 6, 8, 9, 10, 11, 12, and 13) were gram-negative, whereas the four strains (4, 5, 7, and 14) were gram-positive. This study will help us to identify various endophytic bacteria that could play a role in nodule formation and adaptation of soybean plants in diverse soil conditions of Pakistan.