Hatching characterisation of cereal cyst nematode（Heterodera avenae） in Jiangsu Province and optimization of the pathotype bioassay | 燕麦孢囊线虫江苏群体的孵化特征及致病型测定条件优化

Chinese. 摘　　要：在室内条件下测定了燕麦孢囊线虫江苏沛县闫集镇群体在不同处理温度和时间下的2龄幼虫孵化特征,同时评价了不同规格小麦种植容器和线虫接种密度对单株小麦白雌虫量的影响,优化了燕麦孢囊线虫致病型测定条件。结果表明：燕麦孢囊线虫江苏群体的孢囊经过低温刺激才能孵化出2龄幼虫。孢囊经5℃低温预处理8周后,在10、15和20℃条件下均能孵化,其中最适孵化温度为15℃,而25℃条件下仅有少量线虫孵化,28和30℃条件下线虫不能孵化。延长低温预处理时间有助于幼虫孵化。孢囊经14周低温预处理后置于15℃条件下,2龄幼虫的单周孵化高峰及累积孵化率均达到最高值,分别为322条和62%。2龄幼虫不同接种密度显著影响致病型测定中单株小麦白雌虫量,在不同规格的小麦栽种容器里每cm-3接种4条2龄幼虫时,单株小麦产生的白雌虫量最多。本研究优化的致病型生物测定条件,不仅可节约2龄幼虫接种量,而且可提高鉴别寄主抗感病评价的准确性。

English. In lab condition,the hatching characters of Heterodera avenae from Yanji Town in Peixian,Jiangsu Province were studied under the influence of temperature and time,and the number of white females produced on wheat seedlings was evaluated by the influences of container size and inoculum density.The results showed that the hatching of juveniles from Jiangsu population was stimulated by cold temperature.The second stage juveniles hatched at 10,15 and 25 ℃ after cysts pre-treated at 5 ℃ for 8 weeks.Juveniles hatched the most at 15 ℃.However,a few juveniles hatched at 25 ℃ and no juveniles at 28 ℃ and 30 ℃.Juvenile hatching was also improved by the extension of cold pre-treated period.When the cysts pre-treated at 5 ℃ for 14 weeks was incubated at 15 ℃,the juveniles hatched during one week interval was the highest with the number of 322 and the cumulative hatching rate was 62%.In pathotype bioassay,the number of white females produced on wheat seedling was significantly different in different inoculum densities.The wheat seedlings planted in different size of containers and inoculated with density of 4 juveniles per cm3 soil produced the largest number of white females.The optimized conditions for pathotype bioassay not only decreased the number of nematode inoculum,but also increased the evaluation accuracy for resistance/susceptible by differentiate hosts.