Introduction of some new endophytic bacteria from Bacillus and Streptomyces genera as successful biocontrol agents against Sclerotium rolfsii

Abstract

Endophytic bacteria live inside plant tissues without causing disease and not only promote plant growth but can also protect plants against plant pathogens. During 2010–2011 crop years, some endophytic bacteria were collected and are then biochemically and molecularly identified (16srRNA) from bean farms of East Azarbaijan, Iran. Among these bacteria isolates, four isolates from Bacillus genera and four isolates from Streptomyces genera were selected for evaluation of their ability for biocontrol of Sclerotium rolfsii in laboratory and glasshouse conditions. Except one isolate named Streptomyces parvus, the rest of isolates could significantly inhibit mycelial growth in dual culture on PDA medium. All seven selected isolates showed significant inhibition in disease treatments in glasshouse experiments. Biological traits, such as length, wet and dry weight of roots and stems in endophytic bacterial treatment showed no differences with healthy control.

Keywords:

• biocontrol
• endophytic
• Bacillus
• Streptomyces
• Sclerotium rolfsii

Acknowledgements

This study was a part of MSc thesis of the first Author which has been submitted to Plant Protection Department, University of Tabriz, Iran. We would like to express our gratitude to all academic and non-academic staffs in Soil biology lab and Plant Bacteriology, Plant Virology and Mycology labs in Faculty of Agriculture University of Tabriz, Iran.