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 .