春季不同时期低温胁迫对冬小麦茎基腐病发病特征的影响

Effects of Low Temperature Stress at Different Stages in Spring on the Pathogenesis of Stem Base Rot of Winter Wheat

明确春季不同时期低温胁迫对小麦发病特征的影响,旨为拓宽冬小麦茎基腐病发病机理提供新的研究思路。采用盆栽试验,以石优17(中抗茎基腐病)和藁优2018(高感茎基腐病)为试材,播种前在基质中混入含有假禾谷镰刀菌的接种体,分别在起身前期、起身后期、拔节期和抽穗期利用人工模拟低温环境的方法进行连续3 d的低温处理,以自然条件下生长的植株为对照(CK),在低温胁迫结束后第10天和第20天各测定1次小麦的病茎率和病情指数。结果表明:低温胁迫结束后第10天,石优17低温处理的平均病茎率为53.4%、平均病情指数为40.9,藁优2018低温处理的平均病茎率为64.1%、平均病情指数为52.0,均显著高于其CK;低温胁迫结束后第20天,石优17低温处理的平均病茎率为64.3%、平均病情指数为47.3,藁优2018低温处理的平均病茎率为68.7%、平均病情指数为58.9,均显著高于其CK。低温胁迫会加重小麦茎基腐病的发生,小麦起身前期低温处理对植株病茎率影响不显著,而低温出现的时间越晚,小麦茎基腐病的发病程度越重;低温胁迫下,感病品种较中抗品种发病严重。

The purpose of clarifying the effects of low temperature stress on the pathogenesis of wheat at different stages in spring is to provide new research ideas for broadening the pathogenesis of stem base rot of winter wheat.Using pot experiment,Shiyou 17(moderately resistant to stem base rot)and Gaoyou 2018(highly susceptible to stem base rot)were used as test materials.Inoculants containing Fusarium graminearum were mixed into the substrate before sowing.The plants grown under natural conditions were used as control(CK)for 3 d by artificially simulating low temperature environment at the early rising stage,late rising stage,jointing stage and heading stage respectively.The diseased stem rate and disease index of wheat were measured on the 10th and 20th day after low temperature stress.The results showed that on the 10th day after low temperature stress,the average diseased stem rate and disease index of Shiyou 17 and Gaoyou 2018 were 53.4%and40.9 respectively,which were significantly higher than those of CK.On the 20th day after the end of low temperature stress,the average diseased stem rate of Shiyou 17 with low temperature treatment was64.3%,and the average disease index was 47.3.The average diseased stem rate of Gaoyou 2018 with low temperature treatment was 68.7%,and the average disease index was 58.9,which were significantly higher than that of CK.Low temperature stress will aggravate the occurrence of stem base rot of wheat,and the effect of low temperature treatment on diseased stem rate is not significant.Under low temperature stress,the disease of susceptible variety was more serious than that of moderately resistant variety.