论文部分内容阅读
上一年晚玉米病株上采集的丝黑穗病菌孢子粉,贮藏一个冬、春后,配成0.4％菌土,接种于晚玉米上,在田间可引致45.8％的发病率,而当年早玉米病株上采集的孢子粉引致的发病率平均为25.5％。同一生长季节采集的菌粉,因采集时机的不同和菌粉质量的好坏,也直接影响到发病率的高低,高的达31.4％,低的21％左右。在人工接种条件下的成株期症状,42.9％病株的雄花和果穗都表现黑穗症状,33.7％的病株果穗变黑穗而雄花正常。苗期症状虽然确诊率较低,但也有某些特征可供鉴别参考。不同播种期的晚玉米,其发病的多少与玉米4叶期前,特别是出苗期(4～5天)的土壤温度和含水量有密切关系。温度过高,土壤过干或过湿均不利于侵染。
Spore powdery mildew collected on the maize diseased strain of the previous year was stored for one winter and spring and then mixed with 0.4% geo-soil. The inoculation on late maize resulted in a 45.8% incidence in the field, The incidence of spore powder collected on maize diseased plants averages 25.5%. The same growth season collected bacterial powder, due to the collection of different timing and the quality of bacterial powder, but also directly affect the level of incidence, high up to 31.4%, low about 21%. In the artificial seeding condition, the symptom of adult stage showed that the male flower and the ear of 42.9% of the diseased plants showed the black ear symptom, while the 33.7% of the diseased plants turned black ear and the male flower was normal. Although the diagnosis of seedling symptoms is low, but there are some characteristics for the identification of reference. Late corn at different sowing dates has a close relationship with the soil temperature and water content before the 4th leaf stage of corn, especially in the emergence stage (4 ~ 5 days). Temperature is too high, the soil is too dry or too wet are not conducive to infection.