旱稻孢囊线虫（Heterodera elachista）孵化特性研究

为了解旱稻孢囊线虫的孵化特性,从水稻根系及根系附近土壤分离孢囊,在室内离体条件下研究不同温度及水稻根系分泌物、土壤浸液、水稻根汁等因子对2龄幼虫孵化的影响,并观察不同温度下2龄幼虫的存活能力.结果表明:旱稻孢囊线虫孵化的适宜温度范围为28～32℃,且在该温度范围初孵2龄幼虫的存活率高、存活时间相对较长,35℃下孵化率及初孵2龄幼虫的存活率、存活时间均明显下降,40℃下无线虫孵化,20℃下孢囊线虫孵化率仅为0.9％,4℃下可延长2龄幼虫的存活时间.水稻分泌物、水稻土壤浸液和水稻20倍根汁对旱稻孢囊线虫孵化具有刺激作用,5倍根汁和4 mmol/L氯化锌溶液对线虫的孵化有抑制作用.上述结果可为制定旱稻孢囊线虫防治措施提供依据.

Hatching characteristics of the rice cyst nematode Heterodera elachista

This study aimed to understand the hatching characteristics of the rice cyst nematode,Heterodera elachista Ohshima.Cyst nematodes were obtained from soil samples and harvested rice root samples.Several factors were studied to determine their effects on hatching and viability of second-stage juveniles(J2) from cysts of H.elachista in vitro.The tests indicated that the optimum temperature range for emergence of J2 from cysts of H.elachista was 28 ℃-32 ℃.The survival rate and survival time of newly hatched J2 were higher at 28 ℃-32 ℃,which significantly descended at 35 ℃.No juveniles emerged from cysts at 40 ℃,and hatching rate of cysts at 20 ℃ was 0.9%.The survival time of hatched juveniles might be prolonged at 4 ℃.The root diffusate of rice,leachate of rice soils and twenty-time rice root juice stimulated emergence of J2 from cysts,five-time rice root juice and 4 mmol/L zinc chloride solution inhabited emergence of J2 from cysts.The results provided a reference for formulating strategies for controlling the rice cyst nematode.