鞘腐病发生程度与玉米倒伏及产量损失间的相关性分析

为深入探讨鞘腐病的发生对玉米倒伏及产量的影响,通过温室接种法测定了玉米不同发育阶段鞘腐病的发病程度及相关防御酶活性,以确定玉米鞘腐病的易感时期;并通过田间接种不同浓度的层出镰孢菌获得不同发病级别的玉米鞘腐病病株,于乳熟期调查病害发生程度,利用YYD-1B数显植物茎秆强度检测仪测定每株玉米茎秆的抗倒伏能力,收获后测定其产量。结果显示,玉米鞘腐病的易感时期为开花期,郑单958和浚单20在此时期鞘腐病的发病率分别为64.36%和40.22%;病情指数分别达42.73和19.58,均高于其它时期;玉米自交系OH43Ht1、郑58和杂交品种郑单958的茎秆抗倒伏能力均随着玉米鞘腐病发病级别的升高而降低;郑58和郑单958的产量随玉米鞘腐病发病级别的升高而降低,每公顷产量损失郑58从13.84%增加到29.53%、郑单958从3.99%增加到16.72%。表明玉米鞘腐病严重发生时能够降低玉米的抗倒伏能力和产量,且对自交系的影响大于杂交品种,生产中应引起高度重视。

Analysis of the correlation between diseased-degree of corn sheath rot and corn lodging and yield loss

In order to investigate the impact of corn sheath rot on corn lodging and yield loss, the disease severity and defensive enzyme activities at different corn developmental periods were measured by inoculating pathogens in the corn in the greenhouse, and the susceptible period of the disease was identified. In this study, corns with different disease degrees were obtained by inoculating different concentrations of spore suspension of Fusarium proliferatum in the field. The disease degree at the milk stage of corn was also investigated. The lodging resistance of corn was measured by the YYD-1B digital display plant stem intensity detector, and the yield was determined after harvest. The results showed that the susceptible period of corn sheath rot was the flowering period. The incidence rate of Zhengdan 958 and Jundan 20 were 64.36% and 40.22%, and the disease indexes were 42.73 and 19.58, which were higher than these at other periods. The stem lodging resistance of inbred lines OH43Ht1, Zheng 58 and hybrid variety Zhengdan 958 decreased with the increase of disease-degree of corn sheath rot. The yields of Zheng 58 and Zhengdan 958 decreased with the increase of the corn sheath rot disease level. The yield loss of inbred line Zheng 58 increased from 13.84% to 29.53%, and Zhengdan 958 from 3.99% to 16.72% per hectare, respectively. The results indicated that it could reduce the lodging resistance and yield when corn sheath rot occurred seriously, and the effect on inbred lines was greater than hybrids, which should be paid attention to in the agricultural production.