Abstract: Rice blast disease， caused by Magnaporthe oryzae， was one of the most devastating fungal diseases of rice. It was very important to monitor airborne conidial density of M. oryzae in fields for forecasting and control of blast disease. In present study， a qPCR detection method for conidia of M. oryzae was developed， based on M. oryzae MHP1 gene as the target sequence. Airborne conidia of M. oryzae in fields were trapped and quantified using this method. The results showed that airborne conidia population of M. oryzae was largely fluctuant， and indicated that the conidia release of M. oryzae was obviously affected by meteorological conditions during the monitoring periods. Generally， this qPCR method could be used to detect and quantified airborne conidia of rice blast fungus in fields.

Key words: Key words: rice blast, amount of conidia, spore trap, qPCR, meteorological factor