Inoculation and colonization of isolated entomopathogenic fungi Beauveria bassiana in rice plants, Oryza sativa L. through seed immersion method

Abstract

Background The aims of the present study were to isolate and identify native entomopathogenic fungi, Beauveria bassiana from the Egyptian soil and to evaluate the artificial establishment of B. bassiana as endophytes in rice plants through seeds immersion. Results Ten soil samples were collected from different cultivated fields at the Ismailia Governorate. Only one sample was positive with a ratio of 10%. Sequencing of the internal transcribed spacer (ITS) region indicated that the isolate obtained from the soil sample belongs to B. bassiana and was registered under the accession no. MN337282. To test the endophytic colonization of B. bassiana, rice seeds were soaked by B. bassiana with a concentration of 5 × 107 spores/ml, to test when B. bassiana become an endophyte in rice plants. The plants were examined for endophytic presence of B. bassiana, 30 days post treatment. PCR amplification using fungal specific primers for a conserved region of β-tubulin gene yielded identical 360 bp products from both B. bassiana and rice treated plants. Conclusion The results showed that seeds immersion with a conidial suspension proved to be a good method to introduce B. bassiana into rice leaves to protect the rice plants against stem borers.