玉米黑束病研究病害症状与病原生理特性的研究

Identification and Physiological Properties of Black Bundle Disease of Corn

玉米黑束病菌〔Acremonium strictum W.Gams(Cephalosporium acremonium Cda)〕产生的症状类型,主要是髓部出现黑束型和褐节型;叶部出现淡紫红枯死型和个别品种产生黄白色枯死型.病原菌只侵染玉米.菌丝在 PDA 培养基上生长适温28～30℃,孢子萌发为20～33℃,致死温度50℃.该菌对 pH 值适应范围广,但以 PH 值6最佳.紫外线与黑暗和光照与黑暗各12h 交替处理有利于菌丝生长.在 PDA、蔡氏、马丁、玉米粉培养基上生长良好,在玉米粉、PDA 上产孢量最大.玉米茎髓提取液有利于菌丝生长.该菌能利用多种碳源,尤以蔗糖,D(+)葡萄糖最好,在可溶性淀粉培养液中产孢量最多.无机氮对菌丝生长较有机氮为好,其中磷酸氢二铵和碳酸氢铵最隹.

The pathogenic fungus of black bundle disease of corn Acremonium stricturn W.Gams(Cephalosporium acrernonium Cdv.)caused thin purplish-red withered spots on leaves of most varieties and yellowish-white withered spots on leaves of a few varieties.The optimal temperature for hyphal growth on PDA was 28～ 30℃.The spores germinated at 20～33℃.The lethal temperature was 50℃.The fungus could withstand a wide pH range,with an optimum of pH 6.0.Mycelia grew well when treated alternately with ultraviolet ray and darkness or with light and darknss(each last- ing 12 hours),and the fungus developed well on PDA,Cai,Martin and corn meal cul- ture media.Spore production was highest on PDA and corn meal culture medium,and the hypha also grew well on the extrates of corn medulla.The fungus could efficiently use various kinds of carbon sources,especially sucrose and D-(+)-glucose.Spore pro- duction on soluble starch culture medium was twelve and thirteen times higher than on the former two media.Organic nitrogen was less suitable for hyphal growth than inorganic nitrogen,among which(NH_4)_2HPO_3 and NH_4HCO_3 were the best.