Screening for Nematicidal Activities of Bacillus Species Against Root Knot Nematode (Meloidogyne incognita)

摘要

Aims: The aim of this study is to screen for nematicidal activities of Bacillus species against root knot nematode ( Meloidogyne incognita ). Study Design: Randomized complete block design was used for this study Place and Duration of Study: This work was done in Research and Development Division, Malaysian Pepper Board in January 2011 to December 2012. Methodology: In this study, bacteria were isolated from pepper farm, the use of these strains was evaluated to control root knot nematode in vitro and the effectiveness of the antagonistic strains in greenhouse condition was investigated. Results: Four rhizobacteria with nematicidal activity were isolated. Among these strains, nematotoxicities of Bacillus strains were intensively analyzed. Bacillus spp strains MPB04 and MPB93 showed remarkable nematicidal activity of 76.4 and 50.6%, killed tested nematodes within 2 h and completely destroyed tested nematode within 12 h. The results also showed that nematicidal activity displayed by Bacillus strains is related with their proteolytic activity. The pot trial also revealed that the application of Bacillus strain MPB04 and MPB93 reduced the root population of M. incognita by 60.95 and 35.28%, respectively over control. This indicated that these bacterial isolates could reduce the ability of M. incognita to reproduce in soil. Conclusion: The coherence of results by chemical, genetic and greenhouse analysis has further strengthened the hypothesis that nematicidal activity displayed by Bacillus strains is related with their proteolytic activity responsible for nematode penetration by bacteria strains.