条斑型玉米圆斑病病原鉴定及其生物学特性研究

 本研究通过致病性测定、形态学和分子生物学鉴定方法,首次明确陕西省发生的玉米条斑型叶斑病是玉米圆斑病的一种症状类型,由玉米生离蠕孢(Bipolaris zeicola)3号生理小种引起。供试品种豫玉22、农大108、农大3138、东单7号、沈单10号、沈单16号、户单4号、新陕资1号、高农1号和陕单9号都对3号生理小种表现感病,品种间抗病性差异不显著。此菌在PDA、PSA、OMA、CMA、WA和Czapek上均可生长,最适生长培养基为PDA。菌落生长温度为5~35℃,最适菌落生长温度为25℃。分生孢子在5~40℃均可萌发,低于5℃高于40℃萌发率极低,萌发的最适温度为28℃。孢子在pH 3~11均可萌发,萌发最适pH为5。在自来水中分生孢子可以萌发,蔗糖和葡萄糖溶液可以明显促进孢子萌发。

Identification and biological characteristics analysis of corn leaf spot caused by Bipolaris zeicola in Shaanxi Province

Narrow and linear lesions on the leaves of mature corn plants were observed in several counties of Shaanxi Province, China. Pure isolates from host tissues were obtained by isolation from four counties. Pathogenicity test and random amplified polymorphic DNA(RAPD) analysis were performed and the results confirmed that the disease was caused by race 3 of Bipolaris zeicola. Resistance of ten varieties widely planted in Shaanxi was assayed, they were all high susceptible to the pathogen. Temperature for colony growth of the race ranged from 5-35℃ and the optimum growth temperature was 25℃. Conidia could germinate in the range of 5-35℃ and best at 28℃;conidia could germinate under pH 3 to pH 11 and pH 5 was optimal for germination;Conidia could germinate in tap water, glucose and sucrose would stimulate germination obviously.