苗期PCR检测玉米丝黑穗病的取样时期及部位研究

Different Growing Stages and Parts of Maize Head Smut During Seeding Stage by PCR

以2份抗病及2份感病玉米自交系为试验材料,模拟玉米丝黑穗病适宜的侵染及田间发病条件,采用室内菌土接种方法培养玉米幼苗,通过PCR检测病原菌侵染率,研究苗期PCR检测抗、感玉米自交系的最佳取样时期和检测部位。结果表明,SSR标记SR3可用于玉米丝黑穗病室内接种鉴定;同一自交系不同的取样时期叶鞘侵染率均显著高于叶片侵染率;感病自交系与抗病自交系三叶期第3叶叶鞘的PCR侵染率差值极显著高于其他取样时期和取样部位,且该期4份自交系的侵染率与田间接种条件下的发病率呈显著正相关,为鉴别抗感自交系最佳的取样时期和部位。

Two resistant and two susceptible maize inbred lines were tested by indoors inoculation method in seedling stage. Disease incidence came from PCR result under modeling field conditions, aimed to obtain the best sampling period and check position for PCR detection. The results showed that SSR markers SR3 could be used in detection of head smut in indoor infection condition. There was higher incidence of each inbred line from leaf sheath than leaf in different sampling periods. The best sampling period and check position were three-leaf seedling and sheath of the third leaf apart through the comparison analysis of the average difference of incidence rate between re- sistant and susceptible inbred lines. This conclusion was further supported by regression analysis that there was a significant positive correlation between incidence rate indoor and the field.