高粱新病害顶腐病的初步研究

 我国高粱上发生的新病害顶腐病是由亚粘团串珠镰孢(Fusarinm moniliforme var.subglutinans Wr.&Reink.)侵染引起的。病菌生长的适宜温度为25~30℃,适宜pH值为6~8。小型分生孢子萌发的适宜温度为25~28℃,适宜pH值为6~7。病菌在Bilai培养基上,pH4~11间均易产生大型分生孢子。黑光灯和日光灯照射对大型分生孢子形成有促进作用,且黑光灯优于日光灯;在光照处理下最适宜产生大型孢子的培养基为小麦粒和高粱粒。病菌在PSA培养基上培养10~12天后可产生厚垣孢子。病菌能利用多种碳源,以半乳糖、甘露糖为佳,乳糖、木糖、葡萄糖次之。对氮源利用远不及碳源。人工接种条件下,病菌能侵染高粱、苏丹草、哥伦布草、玉米、谷子、珍珠粟、薏苡、水稻、燕麦、小麦、狗尾草等禾本科植物。

THE OCCURRENCE AND PRELIMINARY STUDIES ON SORGHUM TOP ROT

There occurred a new disease, top rot,of sorghum caused by Fusarium moniliforme var. subglutinans Wr. & Reink. The optimum temperature for fungus growth in culture was 25-30℃, and for germination of microconidia was 25-28℃. The optimum pH values for mycelium growth was pH6-7, and for microconidia germination was pH6-8. The macroconidia were readily produced from mycelial culture on Bilai medium of pH values 4 to 11. Both ‘black light’ and fluorescent light treatment favoured the macroconidia production, and the ‘black light’ showed better effect than the fluorescent light. Chlamydospores were produced from mycelia and macroconidia on PSA medium after 10-12 days. The fungus grew better in many kinds of sugar as the carbon sources, such as galactose, mannose, lactose, xylose and dextrose. The medium which only contained nitrogen sources was not in favour of the pathogen growth. Under artificial inoculation, the pathogen could infect cereal plants such as sorghum, sudangrass, Columbus grass, corn, foxtail millet, pearl millet, jobstears, rice, oat, wheat and green foxtail.