甘肃苜蓿斑点病的初步研究

The Pathogen of the Medicago stativa Leaf Spot in Gansu Province

近年来甘肃省苜蓿(Medicago stativa L.)发生一种叶部病害——斑点病,严重地降低了苜蓿的产量和饲用价值。为了有效地控制该病害对苜蓿的危害,在室内对其病原菌进行了形态学鉴定及生物学特性研究。结果表明:苜蓿斑点病的病原菌为链格孢菌(Alternaria alternata (Fr.:Fr) Keissler),该病原菌能很好地利用麦芽糖、蔗糖、甘氨酸;其生长最适温度为25℃,最适pH为6.0-7.0,最适宜的RH为98%以上,最适培养基为5%AL和PSA。在上述环境条件下,菌丝生长快,菌丝茂盛,产孢量大,孢子萌发率高。

Leaf spot is a serious leaf disease in alfalfa,which have been in Gansu Province in recent years.The disease reduced yield and forage value of alfalfa.In order to effectively control the disease of alfalfa,the morphology and biological characteristics of the pathogen was made in laboratory.The results indicated that it was caused by Alternaria alternata（Fr.：Fr） Keissler.The Pathogen can utilize sucrose,maltose,glycin Well.The optimum temperature,pH value and relative humidity（RH） of the pathogen are 25℃,6.0-7.0,above 98% respectively.Under such conditions the pathogens grow quickly,the aerial mycelium of colony is abundant,the conidia germinate well.