pH对木霉菌和镰刀菌生长及其竞争的影响

Effect of pH on the growth and competition of Trichoderma spp.and Fusarium spp

由镰刀菌引起的茎基腐病对西番莲生产造成了严重威胁,然而目前缺乏对其有效的生物防治手段。木霉菌是目前应用最广泛的生防真菌,能够有效防治多种作物病害,但是其防治效果容易受到环境因素如土壤pH的影响。为筛选西番莲茎基腐病的潜在生防菌株并探究pH对木霉菌防治效果的影响,本研究选取从热带西双版纳西番莲种植区分离的4种木霉菌和4种镰刀菌作为材料,通过菌丝生长速率法测定不同菌株在不同pH条件下的生长动态,并采用平板对峙试验探究pH对木霉菌抑制镰刀菌生长效果的影响。结果表明:木霉菌的最适生长pH为4~6,而镰刀菌的最适生长pH为7~9。4种木霉菌对4种镰刀菌的生长均具有显著的抑制作用,其中,哈茨木霉的抑制效果最显著,抑制率可达72%。此外,pH对木霉菌的抑菌效果具有显著影响,且因木霉菌和镰刀菌种类的不同也表现出差异。因此,针对特定的病原菌和生防菌种类,在田间进行生物防治时需关注环境pH对生防菌防治效果的影响。

Collar rot caused by Fusarium spp.is a serious threat to the production of Passiflora edulis.However,biocontrol methods are lacking.Trichoderma spp.,as the most widely applied biocontrol fungus,can be effective in managing crop diseases.The effectiveness is significantly influenced by environmental factors,such as soil pH.To screen potential biocontrol strains against collar rot of P.edulis,and to explore the effect of pH on the inhibition rate of Trichoderma spp.,we selected four Trichoderma species and four Fusarium species isolated from P.edulis planting area in Xishuangbanna.The growth dynamics of different strains under different pH conditions were deter-mined using the mycelial growth rate method.The effect of pH on the growth inhibition of Fusarium spp.by Tri-choderma spp.was investigated using the plate confrontation assay.The results showed that the optimal growth pH range was 4-6 for Trichoderma spp.and 7-9 for Fusarium spp.All four Trichoderma strains exhibited significant in-hibitory effects on the growth of the four Fusarium strains.T.harzianum showed the most notable inhibition,reac-hing up to a 72%inhibitory rate.Moreover,pH significantly influenced the inhibitory effect of Trichoderma spp.,with variations observed depending on the specific species of Trichoderma spp.and Fusarium spp.Therefore,it is essential to consider the environmental pH impact on the efficacy of biocontrol agents when applying biological con-trol measures in the field,tailored to the specific pathogen and biocontrol agent involved.