玉米褐斑病流行规律及GEM种质资源抗病性鉴定

近几年玉米褐斑病发生逐渐严重,已成为玉米生产上的一种主要病害。2007～2009年连续3年对冀东地区玉米褐斑病的发生规律进行了调查,并对57份美国GEM种质资源进行了田间自然发病条件下的抗病性鉴定。结果表明,7月份的降雨量是褐斑病流行的重要因素,Logistic模型能较好地拟合降雨量对褐斑病流行的影响;玉米拔节期是褐斑病防治关键期,当累积降雨量达到247.7 mm时要及时进行防治。抗病性鉴定结果表明,GEM种质资源中有37份免疫材料,占鉴定总数的64.91%;有8份抗性材料,占总数的14.03%。

Epidemic Regularity of Maize Brown Spot and Resistance Identification to GEM Breeding Materials

Maize brown spot caused by Physoderma maydis is increasing serious and has been a main disease of maize in recent years. Epidemic regularity of maize brown spot was studied in three consecutive annual from 2007 to 2009 in Jidong zone and resistance to GEM germ plasm resource of maize, total of 57, was identified in the fields. The result showed that rainfall in July is an important factor to affect brown spot epidemic dynamics. The relation between rainfall and disease index of brown spot could be simulated by Logistic models. The maize joint stage when accumulated rainfall to 247.7 mm after infection was the best control condition for the disease. And the 37 immune materials, accounted for 64.91% in total, 8 resisted materials, 14.03% to maize brown spot were identified.