连作谷子根腐病病原鉴定及其致病性分析

Identification and pathogenicity of the pathogen causing root rot on continuous-cropping foxtail millet

0引言近几十年来,受土地资源限制和区域产业发展的要求,以高投入与高产出、种植类型单一化、土地高强度利用等为特点的集约化种植已成为我国农业生产中典型的生产模式^([1])。连作导致作物产量和品质下降、病害频发、土壤肥力衰退等问题日益突出,成为农业可持续发展中的重大问题之一^([2])。

Foxtail millet(Setaria italica(L.)Beauv.),a novel model species in C4 gramineae crops,plays a principal role in food security in Africa and Asia and in the adjustment of the crop planting structure in China.It is sensitive to continuous cropping,which is a serious constraint to the production and the quality.Root rot disease is typical for the diseased foxtail millet in continuous cropping fields.In this study,a fungus was obtained from the rotten root millet samples and grouped according to their colony morphology,namely,YDSi-1,YDSi-2 and YDSi-3.According to pathogenic tests fulflling the Koch's postulate,YDSi-3 showed a strong pathogenicity for root rot of foxtail millet.Based on morphological and molecular identification,YDSi-3 was identified as Fusarium oxysporum.This is the first report of F.oxysporum causing root rot of foxtail millet in China,and will provide a theoretical basis and technical support for the control on the continuous cropping of foxtail millet in the future.