三株生防酵母菌对Botrytis cinerea的抑菌作用研究

Study on antifungal activities of biocontrol yeasts against Botrytis cinerea

针对三株生防酵母菌Cryptococcus albidus 63(Ca63)、Cryptococcus albidus 64(Ca64)、Candida parapsilosis yett1006对番茄灰霉病病原菌B.cinerea t08016b的抑菌作用进行研究。三株生防酵母菌与B.cinerea t08016b的对峙培养过程中,未产生明显抑菌圈,均可减弱B.cinerea t08016b生长势;几丁质酶和β-1,3-葡聚糖酶活性测定结果表明,t08016b并无诱导三株酵母菌分泌酶活显著增加(P>0.05);研究酵母菌对B.cinerea t08016b菌丝生长和孢子萌发率影响发现,C.albidus 63、C.albidus 64和C.parapsilosis yett1006对菌丝生长量的抑制率分别为88.57%、90.66%和85.65%,高浓度菌液对孢子萌发有显著抑制效果,1×108cfu·mL-1菌体活细胞能完全抑制病原菌孢子萌发,菌体活细胞浓度越低抑制效果越不明显,无菌滤液和灭活的菌体活细胞对病原孢子的萌发无显著抑制效果。结果表明,生防酵母菌主要通过竞争有限的生长空间和营养条件,而非通过分泌抑菌物质实现拮抗作用。

In this study, the antifungal activities of biocontrol yeasts Cryptococcus albidus 63（Ca63）, Cryptococcus albidus 64 （Ca64） and Candida parapsilosis yett1006 against Botrytis cinerea were investigated. The dual culture between three biocontrol yeasts and B. cinerea t08016b results showed that no obvious inhibiting zone appeared, but the pathogen growed more weakly than the control. The results of chitinase andβ-1, 3-glucanase activities assay showed that the levels of the two enzymes activities did not change significantly （P＆gt;0.05） when the three biocontrol yeasts cultured with pathogen. The inhibition rates of three biocontrol yeast strains on mycelium growth were 88.57%, 90.66% and 85.65%, respectively. High concentrations of biocontrol yeasts had a strong inhibitory effect on the spore germination of B. cinerea t08016b. Especial y, 1 × 10^8 cfu·mL^-1 biocontrol yeasts almost stopped the spore germination of B. cinerea t08016b. Heat-inactived yeast suspension and culture supernatant had no significant inhibitory effects on B. cinerea. These results il ustrated that the antagonic effect of biocontrol yeasts was mainly due to the competition of limited space and nutrient conditions, not secreting antifungal substances.