关键词: 淡紫拟青霉, 南方根结线虫, 插入突变, 致病力, 酶活力

Abstract: [Objective] The objective of this study was to investigate that protease and chitinase and their pathogenicity against Meloidogyne incognita when the genome of mutants of nematophagous fungus Paecilomyces lilacinus are inserted by T-DNA. [Method] Chitinase and protease activity are important indicators which can evaluate the biological control potential of P. lilacinus. These chitinase activity and protease activity of the mutants were analyzed and pathogenicity against Meloidogyne incognita was assayed. [Results] The chitinase and protease activities of mutants were affected at different levels after T-DNA was inserted into genomes. The tested 14 mutants were different on parasitic rates of nematode eggs. The pathogenicity of 1 mutant was increased but The pathogenicity 11 mutants was decreased significantly. According to the analysis, no positive correlations were detected between the activities of protease, chitinase of mutants and parasitic rates. [Conclusion] The study confirmed that chitinase and protease activities and parasitic rates were affected at different levels when T-DNA inserted into genomes. Additionally, the study may be helpful to understand the pathogenic mechanism of P. lilacinus and clone genes related to pathogenicity.

Key words: Paecilomyces lilacinus, Meloidogyne incognita, insertional mutagenesis, pathogenicity, enzyme activity