河西走廊制种玉米生育中后期叶部真菌病害诊断与病原初步鉴定

对河西走廊制种玉米生育中后期叶部真菌病害进行田间调查,并将采集到的标本进行组织分离、病原鉴定和致病性测定。结果表明,引起制种玉米生育中后期叶部真菌病害的植物病原有13种,其中由Curvulairia lunata(Wakke)Boed病原引起的玉米弯孢菌叶斑病是玉米叶部的一种新病害,在田间发病率较高,病情指数较大,危害十分严重;由Exserohilum turcicum(Pass.)Leonard et Suggs和Bipolaris maydis(Nishik.et Miyabe)Shoemaker病原引起的大斑病和小斑病是玉米生育中后期叶部发生的主要真菌病害;Physoderma maydis Miyabe和Fusarium subglutinans(Wollenwe.et Reinking)P.E.Nelson et al病原引起的褐斑病和顶腐病有加重发生的趋势;Puccinia sorghi Schw引起的普通锈病在局部区域的一些品种和组合上发病较为严重;其他叶部病害零星发生,对制种玉米正常的生长发育影响较小,一般不会造成流行为害。

Diagnosis and Preliminary Identification on Pathogeny of Foliage Fungal Diseases at Medium-late Stage of Maize in Hexi Corridor

A series of field survey on foliage fungal diseases of maize at medium-late stage was conducted in the Hexi Corridor, and samples were collected for tissue isolation, pathogen identification and pathogenicity test. The results showed that there were 13 kinds of plant pathogenic fungi at medium-late stage of maize. Curvularia lunata was considered as new and prevalent pathogens to cause corn Curvularia leaf spot disease. Exscrohilum turcicum and Bipolaris maydis caused by Exserohilum turcicum(Pass.) Leonard et Suggs and Bipolaris maydis(Nishik. et Miyabe) Shoemaker were significant traditional fungal diseases of maize. Occurrence and damage of brown spot and maize top rot of corn caused by Physoderma maydis Miyabe and Fusarium subglutinans respectively had an aggravating tendency. The rust caused by Puccinia sorghi Schw was serious in some local varieties and combinations. Others were sporadic leaf disease in the Hexi Corridor, and could not cause epidemiologic damage.