摘要
玉米大斑病的发生流行规律 为了掌握玉米大斑病在田间的发病消长,病菌、发病与气候条件的关系,为玉米大斑病的发生测报及有关防治措施提供依据,我们从1973—1977年进行了下述研究工作:一、病菌越冬生活力测定自当年玉米收获后,于10月间,将玉米病叶放在地下10厘米、地表、玉米秸垛底、玉米秸垛中、玉米秸垛表、冷室内、暖室内七处贮存,分别于翌年5、6月田间第一个病斑出现前取出,用人工孢子形成法(将病叶置于保湿玻皿内,在25℃条件下培养48小时)和自然孢子形成法(将病叶置于田间地表,每两天检查一次),镜检分生孢子产生的有无,直至田间第一个病斑出现时止,以确认越冬后的病原菌是否具有生活力。
The northern leaf blight of corn is caused by the fungus Exserohilum turcicure(Pass.)Leonard et Suggs.it occurs mostly in the spring-corn areas of northern and southern China and may cause a reduction of yield by 20%in the heavy diseased-season,and even as high as 30—50%in some severely infecte d fields,Five years experimental results showed that the mycelium of pathogen overwintering in the field infected plant and produced new conidia spreaded through the air in the second year,Results also showed that the germination rate of overwintering conidia is low,The epidemic of disease in the fields may be divided into three stages:i.e.occurrence,infestation and injury.The number of rainy days and the amount of rain in June,July and August which are main factors effecting the occurrance and epidemic of the disease,may be taken as scales for middle and long term foreasting.More than 1000 of corn inbreds and varieties were tested for their disease resistance in seven years,Many of them with the lesion number form of resistance expressed anti-infection,About 200 isolates of the fungus collected from different parts of China were tested,results showed that all isolates avirulent to plants which having gene Htand Htand expressing chlorotic-Iesion form of resistance might be the race 1(US1)of the Exserohilum turcicum.Utilization of resistance varieties along with an integrated control method can be protected the corn from damage of this disease.
作者
潘顺法
姜晶春
马润芝
白金铠
Pan Shun-fa;Jiang Jing-chun;Ma Run-zhi;Pai chin-kai(Institute of Plant Protection,Jilin Academy of Agricultural Sciences)
出处
《中国农业科学》
1980年第3期78-84,共7页
Scientia Agricultura Sinica
