Antagonistic Effect of Bacillus spp. against Sugar Beet Pathogens Fusarium Wilt

Bayoumy, Samia; Afify, Aida; El-Sayed, A.; Elshal, Samar

doi:10.21608/jacb.2017.38676

Antagonistic Effect of Bacillus spp. against Sugar Beet Pathogens Fusarium Wilt

Document Type : Original Article

Authors

¹ Dept. Microbiology, Fac. Agric. Mansoura Univ., Mansoura, Egypt.

² Plant Pathology Research Institute, Agricultural Research Center (A.R.C), Giza, Egypt.

10.21608/jacb.2017.38676

Abstract

Twenty bacterial isolates were recovered from the rhizosphere of sugar beet cultivars in Egypt. All the isolates have antagonistic effect against three phytopathogenic fungi: Fusarium solani, Fusarium oxysporum and Fusarium dimerum. In vitro all bacteria gave comparable results. Four isolates which showing highly antagonism were identified by standard tests. In vitro it was found that 4 strains very active to antagonism and were namely by biolog system belonging to Bacillus spp.; B. subtilis, B. amyloliquefaciens, B. weihenstephanensis and B. pseudomycoides.In vivo, the highest percentage of survival plants was 86, 90 and 72%by B.amyloliquefaciens, B.pseudomycodies and B. subtilis for the control of F. solani, F. oxysporum and F. dimerum, respectively more than the other Bacillus spp.All Bacillus strains were positive for indole acetic acid production from tryptophan, but it failed to produce HCN. Also, all Bacillus strains were negative for cellulase and chitinase tests.The usage of Bacillus spp. as seed treatment reduced the percentage of damping-off incidence of sugar beet under greenhouse conditions. This result shows that these four Bacillus spp. are very effective biocontrol agents and should be used for further biocontrol applications and should be classified as biocontrol agents.

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