ABSTRACT
The present work was carried out to study the potential of bacteria isolated from the seeds of rice plant for the biocontrol of five rice pathogenic fungi. Eleven endophytic bacteria isolated from rice seeds were evaluated for their antagonistic potential. Of five pathogens studied, only the growth of Magnaporthe grisea was inhibited by one bacterial isolate in an in vitro dual culture assay. Based on 16S rDNA sequence analysis, and biochemical and morphological characteristics, this strain was closely related to Stenotrophomonas maltophilia. We named this new isolate to be S. maltophilia SEN1 (seed endophyte). This isolate was further tested for the production of volatile and diffusible antibiotics against M. grisea, for plant growth-promoting (PGP) traits and colonization of some rice cultivars. In addition, S. maltophilia SEN1 was tested for its ability to promote plant growth and reduce the incidence of rice blast disease under greenhouse conditions. When applied to the soil, this isolate increased seedling growth and suppressed blast disease in plants of three studied cultivars. This study also showed this isolate could colonize the root interior of other rice cultivars. This study indicates that the S. maltophilia isolate studied has an excellent potential to be used as biocontrol agents of M. grisea or biofertilizer under in vitro and in vivo conditions.
Acknowledgment
We wish to thank the University of Tehran for providing the necessary facilities and funding for this study.
Disclosure statement
No potential conflict of interest was reported by the authors.
Additional information
Notes on contributors
Hassan Etesami
Dr Hassan Etesami is a research scientist with 15 years of research experience in the soil biology and biotechnology area. He obtained his doctor’s degree from the Department of Soil Science, University College of Agriculture & Natural Resources, University of Tehran, Tehran, Iran. Dr Etesami has a special interest in developing biofertilizer and biocontrol agents that meet farmers’ expectations. He has coauthored over 30 publications in different areas including biofertilizers and biocontrol. Currently, he focuses on bioremediation and using of endophytic bacteria to reduce the transfer of heavy metals to plant. At the present time, he is as a faculty of the Department of Soil Science at the University of Tehran, Iran.
Hossein Ali Alikhani
Prof. Hossein Ali Alikhani is a research scientist with 20 years of research experience in the soil biology and biotechnology area. He obtained his doctor’s degree from the Department of Soil Science, University College of Agriculture & Natural Resources, University of Tehran, Tehran, Iran. Prof. Alikhani has a special interest in developing biofertilizer and biocontrol agents that meet farmers’ expectations. He has coauthored over 70 publications in different areas including biofertilizers, bioremediation, and vermitechnology. At the present time, he is as a faculty of the Department of Soil Science at the University of Tehran, Iran.