But the principal culprit is Cryphonectria parasitica, the fungus that causes chestnut blight.

但栗疫病菌才是罪魁祸首，是这种真菌致栗树感染了栗疫病 。

Dr Powell knew that many of the symptoms of chestnut blight are caused by the oxalic acid that C. parasitica generates as it grows.

鲍威尔知道，栗疫病的很多症状都由栗疫病菌生长时产生的草酸引起。