The pot experiments were carried out in a greenhouse located at Yixing, China during May to June 2010. The temperature ranged from 23 °C to 30 °C and the relative humidity from 60% to 85%. In the pot experiment, each pot was filled with 150 g of infested soil, and one germinated seed was planted per pot. There were 3 replications of each treatment, and each replication contained 10 pots. The experiment was repeated twice.