In Vitro Bioassay of Purpureocillium lilacinum and Bacillusthuringiensis for Control of Meloidogyne incognita on Black Pepper(Piper nigrum L.) in Sarawak, Malaysia, Northern Borneo

Abstract

This study aimed to evaluate strains of the entomopathogenic fungus Purpureocillium lilacinum and the bacterium Bacillus thuringiensis from Bintulu, in north-eastern Sarawak, Malaysia for their invitro nematicidal properties against different developmental stages of Meloidogyne incognita. Tenindigenous novel strains of P. lilacinum, a commercial strain of the fungus (P. lilacinum M), and a strainof B. thuringiensis carrying Cry6 and Cry14 gene sequences were screened for parasitism against M.incognita females and eggs, egg hatching inhabitation and 2nd stage of active juveniles (J2) mortality. Ourstudy demonstrates that P. lilacinum A and P. lilacinum B were the most effective biocontrol agent againstM.incognita females, eggs and J2 due to highest infection of females, eggs and significant decrease inegg hatching events. P. lilacinum A, P. lilacinum B, and P. lilacinum M (positive control) demonstratedhighly significant infection (>90%, P≤0.01) on M.incognita female nematodes. The present study revealedthat spore suspension (105 spore/mL) of P. lilacinum A, P. lilacinum B and P. lilacinum M resulted in 78.8%,66.0% and 73.4% parasitism on eggs, respectively. P. lilacinum A, P. lilacinum B and P. lilacinum M withlow mortality of 6.0%, 5.5% and 5.7%, respectively, showed significant (P