A study on antifungal properties of root endophytic bacteria against soil borne fungal pathogens in cotton.

摘要

The effects of endophytic bacteria (Bacillus-2, Pseudomonas-1, Bacillus-1, Bacillus-3, Azotobacter and Pseudomonas-2) from cotton on soilborne Fusarium and Rhizoctonia species were studied. In an in vitro assay using the dual culture technique, the root endophytic bacteria suppressed the growth of Fusarium and Rhizoctonia species. In a pot culture experiment, the inoculation of cotton (cv. DH-2) seeds with the bacterial isolates enhanced cotton seed germination, plant height, root length and dry matter, and markedly reduced the incidence of root discoloration due to the soil inoculation of both pathogens. Treatment with Bacillus-3 against Fusarium resulted in the greatest reduction in disease intensity (84.4%), and in the highest values for germination (93.2%), plant height (31.4 cm), root length (33.2 cm) and dry matter yield (18.9 g). However, against Rhizoctonia, Bacillus-1 was the most effective in the reduction of disease incidence (78.8%), and in the enhancement of germination (92.8%), plant height (30.5 cm), root length (31.7 cm) and dry matter yield (19.9 g).