The influence of temperature on breaking of diapause and egg hatching in cereal cyst nematode (Heterodera filipjevi) (Short scientific report)

The cereal cyst nematode Heterodera filipjevi has obligatory diapause stage in life cycle. For this purpose, the effect of different thermal treatments viz. 5, 10, 15, 5+15, 20 and 25°C were tested on the number of egg hatching of H. filipjevi for 12 weeks. The highest hatching rate was observed at 5+15°C with 87.8% whilst the treatment 25°C showed the lowest hatching rate of 1.1%. The treatments 5°C and 5+15 °C with highest hatching rates respectively showed significantly increasing of hatching between the sixth and seventh weeks followed by decreasing from the eighth week. Therefore, a pre-hatching incubation temperature at 5°C for six weeks is required to breaking diapause in Iranian population of H. filipjevi to occur the highest hatching rate at 15°C and by increasing the temperature the hatching rate is decreased.