2株真菌的鉴定及对禾谷孢囊线虫的防治效果

【目的】生防菌株的种类鉴定及对禾谷孢囊线虫Heterodera avenae的防治效果。【方法】以形态学特征和rDNA-ITS序列比对及系统发育树分析相结合的方法鉴定生防菌的种类,测定菌株A1和B1发酵液对孢囊、卵和2龄幼虫的活性及对小麦孢囊线虫病的盆栽防治效果。【结果】菌株A1和B1分别鉴定为寄生曲霉Aspergillus parasiticus和长枝木霉Trichoderma longilbrachiatum。处理14 d后,A1和B1的菌丝对线虫孢囊的寄生率可达80.00%以上。处理12 d后,菌株A1和B1的发酵液原液对卵孵化的抑制率分别为63.98%和67.56%,处理72 h后,对2龄幼虫的校正死亡率分别为68.14%和92.98%。盆栽试验发现,菌株A1和B1的3%菌肥培养物处理90 d后,孢囊减少率分别为31.71%和36.04%,小麦根长分别增加28.82%和59.62%,株高分别增加20.38%和21.43%。【结论】菌株A1和B1对禾谷孢囊线虫具有防治作用,是2株极具开发潜力的生防菌株。

Identification of two fungi strains and their control effects to cereal cyst nematode

Objective To identify the species of biocontrol strains and analyze their control efficiency to cereal cyst nematodes (Heterodera avenae).Method Biocontrol fungus A1 and B1 were identified according to morphological characters, rDNA-ITS sequence alignment and analysis of phylogenetic tree. The control effects of the fermentation broths of strain A1 and B1 against cysts, eggs and the second-stage juveniles (J2) and pot control effects against cereal cyst nematodes were determined.Result Strain A1 and B1 were identified as Aspergillus parasiticus and Trichoderm longilbrachiatum respectively. The mycelium parasitic rates of A1 and B1 on nematode cysts were over 80.00% at 14 days after treatment. At 12 days after treatment, the inhibition rates of the fermentation broths of A1 and B1 on egg hatching were 63.98% and 67.56% respectively. The corrected mortality rates of J2 at 72 hours after treatment were 68.14% and 92.98% respectively. At 90 days after treatment with 3% fungus fertilizer, pot experiment results showed that cyst reduction rates of A1 and B1 were 31.71% and 36.04%, the root lengths of wheat plants increased by 28.82% and 59.62%, and the plant heights increased by 20.38% and 21.43%, respectively.Conclusion Strain A1 and B1 have control effects on cereal cyst nematodes and are worthy of development and utilization.