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通过致病力的测定筛选出两株强致病力核桃基腐病菌菌株HA-1和KY-S,通过对酶活性的分析,研究证实核桃基腐病菌均能分泌4种细胞壁降解酶(CWDEs):β-葡萄糖苷酶、多聚半乳糖醛酸酶(PG)、果胶甲基半乳糖醛酸酶(PMG)、纤维素酶(Cx)。在不同碳源培养条件下,核桃基腐病产生细胞壁降解酶的活性存在一定差异,以蔗糖为碳源时,菌株分泌的各种细胞壁降解酶活性较高。在4种培养基中,达到各酶活性高峰的时间仅为3d。在蔗糖培养基中,核桃基腐病菌产生的Cx最大酶活性为1495.5mU/mL,明显高于其他3种酶,且显著高于其他培养基产生的Cx。但在树皮为碳源的培养基中Cx的活性最低。在CMC为碳源的培养基中PG、PMG的活性最高,分别为826.5mU/mL和661.3mU/mL,此外,以果胶为碳源时产生的PMG的活性最高为1068.0mU/mL。
Two virulent strains of walnut-based pathogenic fungi HA-1 and KY-S were screened out by pathogenicity test. Through the analysis of enzyme activity, it was confirmed that all of the pathogenic bacteria could secrete four kinds of cell wall degrading enzymes (CWDEs ): β-glucosidase, polygalacturonase (PG), pectin methyl galacturonase (PMG), cellulase (Cx). Under different carbon source conditions, there were some differences in the activity of cell wall degrading enzymes in walnut-based rots. When sucrose was used as carbon source, the activity of various cell wall degrading enzymes secreted by the strains was high. In the four media, the time to peak of each enzyme activity was only 3d. In sucrose medium, the maximum activity of Cx produced by Fusarium solani was 1495.5 mU / mL, which was significantly higher than that of the other three enzymes and significantly higher than that of other media. However, Cx activity was the lowest in medium with bark carbon source. The activity of PG and PMG in CMC medium was the highest, which were 826.5mU / mL and 661.3mU / mL, respectively. In addition, PMG produced by pectin as carbon source had the highest activity of 1068.0mU / mL.