Isolation and characterization of Bacillus subtilis EB-28, an endophytic bacterium strain displaying biocontrol activity against Botrytis cinerea Pers.

Abstract

The fungal pathogen Botrytis cinerea Pers. causes severe rotting on tomato fruits during storage and shelf life. As a biological control agent, endophytic bacterium was regarded as an effective alternative to chemical control. Out of 238 endophytic bacterial isolates, three strains (EB-15, EB-28, and EB-122) isolated from Lycopersicum esculentum Mill., Speranskia tuberculata (Bge.) Baill, and Dictamnus dasycarpus Turcz. respectively were found to be strongly antagonistic to the pathogen in vitro and were selected for further in vivo tests. One endophytic bacterium strain, encoded EB-28, was selected from the three in vivo tested isolates. The inhibitive rate of EB-28 reached 71.1% in vitro and 52.4% in vivo. EB-28 was identified as Bacillus subtilis according to its morphological, physiological, and biochemical characteristics and 16S rDNA sequence analysis.

Key words： endophytic bacterium; Bacillus subtilis; Botrytis cinerea Pers; biological control

Acknowledgements

This work was supported by the International Corporation Grant from the Ministry of Science and Technology of the People’s Republic of China (No. 2006DFB72260), and by the Doctoral Grant from Agricultural University of Hebei, China.

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