不同温度对燕麦孢囊线虫田间群体孵化的影响

Effect of temperature on the hatch of Heterodera avenae field population

为明确不同温度经历燕麦孢囊线虫的孵化特点,分别于10月初小麦播种时和土壤结冻前即12月底采集大量燕麦孢囊线虫孢囊,在室内离体条件下分别测试不同温度对其孵化的影响。小麦播种时采集的燕麦孢囊线虫经5℃恒温处理的孵化高峰期为处理后第10～12周,比15℃恒温处理推迟了约4周;前期置于5℃培养,然后再转至15℃处理的孢囊,5℃处理时间越长,孵化高峰期越滞后;此外,随着5℃低温处理时间的增加,其总孵化率具有增加的趋势。12月底采集的孢囊在5～30℃条件下均有孵化,其最佳孵化温度为20℃,在此温度下其总孵化率最高,且孵化期最短;25℃以上高温对卵的孵化具有显著的抑制作用。

The effect of temperature on the hatch of Heterodera avenae population sampled in early of October at wheat sowing period and in end of December before soil freezing was evaluated in vitro for under- standing H. avenae hatching characteristics with different temperature experiences. The results showed that the hatching peak of H. avenae collected in wheat sowing period was 10 - 12 weeks after treatment at constant temperature of 5 ~C. It is about 4 week＇ s delay comparing to that at constant temperature of 15 ℃. For the treatments of pre-incubation at 5℃, then transferring to 15 ℃, the longer the incubation time at 5℃, the more delay the hatching peak; the total hatch increased with increasing incubation time at 5℃. It proved that the low temperature at 5 ℃ was favorable for the total hatch. H. avenae collected before soil freezing （experienced 〈 10℃ for seven weeks） could hatch at 5 -30℃, but the optimum tempera- ture for its hatch is 20 ℃. The highest hatch rate was observed at this temperature and its hatching period was shorter than those at other temperatures. The hatch was significantly inhibited at the temperature of over 25℃.