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为探究卵寄生真菌产生的几丁质酶对南方根结线虫卵孵化的抑制作用,采用分离自黑龙江大豆孢囊线虫孢囊上的菌株CGMCC5328,利用NAG和p NP法测定其几丁质降解酶系和外切酶的活性,分析几丁质酶粗酶液对南方根结线虫卵的孵化抑制效果。结果表明,菌株CGMCC5328经形态学和ITS序列分析鉴定为渐狭蜡蚧菌Lecanicillium attenuatum;在几丁质酶诱导培养基中培养第4天时其分泌的几丁质降解酶系达酶活高峰,为16.90 U/m L;第6天外切酶达酶活高峰,为0.59 U/m L,之后酶活趋于稳定持续至第14天;几丁质酶分子量分别为79.6、65.6、54.1、42.1和32.9 k Da;其中培养第7天的几丁质酶粗酶原液对南方根结线虫卵孵化的抑制率为83.17%;第6天菌株CGMCC5328对卵的寄生率为85.10%。表明高效产几丁质酶的卵寄生真菌渐狭蜡蚧菌菌株CGMCC5328对南方根结线虫卵孵化具有明显的抑制效果。
In order to explore the inhibitory effect of chitinase produced by egg parasitic fungi on the egg hatching of Meloidogyne incognita, the strain CGMCC5328 isolated from the cyst of Cyanotheca sibiricum Heilongjiang was used to determine the chitin degradation by NAG and p NP methods Enzyme activity and exo-enzyme activity, analysis of chitinase crude enzyme activity on the southern root-knot nematode eggs incubation inhibitory effect. The results showed that strain CGMCC5328 was identified as Lecanicillium attenuatum by morphological and ITS sequence analysis. The chitinase-degrading enzyme reached the peak of enzyme activity on day 4 of culture in chitinase induction medium 16.90 U / m L; the activity peak of exonuclease reached 0.59 U / m L on the 6th day, then the activity tended to be stable until the 14th day; the chitinase molecular weights were 79.6, 65.6, 54.1, 42.1 and 32.9 kDa. The inhibition rate of chitinase crude enzyme on the 7th day was 83.17% for egg hatching of M. incognita and 85.10% on day 6 of CGMCC5328. The results showed that egg-producing fungi Chromosomallla gracilis CGMCC5328, an efficient chitinase producing strain, had a significant inhibitory effect on egg hatching of M. incognita.