玉米穗腐引起叶枯的抗性鉴定

Identification of resistance to leaf blight caused by ear rot in maize

【目的】发掘兼抗穗腐与叶枯的优异种质资源,为探索穗腐与叶枯抗性间相互影响的分子调控机制奠定基础。【方法】在传统穗腐病接种方法的基础上进行改良,并对326份骨干自交系和244份RIL群体进行抗性鉴定。【结果】建立了授粉后2 d于穗轴基部接种1 mL孢子数量体积分数为5×10^(6)个·mL^(-1)的拟轮枝镰孢孢子悬浮液的接种体系及其鉴定体系,穗腐引起叶枯抗性在不同自交系间存在较大差异,来自CIMMYT的自交系和P群的自交系抗性较好。【结论】穗腐引起的叶枯抗性与穗腐抗性的比较研究发现,70.9%的自交系表现不同,可能存在不一样的抗性机制。研究还鉴定出14份兼抗玉米穗腐与叶枯的优异自交系。

【Objective】The elite inbred lines screened with resistance to ear rot and leaf blight would be used for resistance breeding in maize and exploring the molecular regulation mechanism of the interaction between the resistance to ear rot and leaf blight.【Method】Improvement on traditional inoculation methods for ear rot disease,and the resistance to leaf blight of 326 inbred lines and 244 RILs were identified.【Result】The inoculation system and resistant criterion were established by inoculating one milliliter of Fusarium verticillioides spore suspension(5×10^(6) spores·mL^(-1))at the base of cob in maize after 2 days pollination,which improved originating from ear rot inoculation method.The resistance to leaf blight caused by ear rot was significantly different among inbred lines.The germplasm originated from CIMMYT inbred lines and P-group were highly resistant.【Conclusion】The part of inbred lines and RILs were used for comparing the resistance to cob rot and that of leaf blight,it was found that the resistance to cob rot of 70.9%of inbred lines was not consistent with the resistance to leaf blight,and there could be different molecular mechanisms.In addition,14 elite inbred lines were identified with high resistance to leaf blight and cob rot.