大豆花叶病毒(SMV)流行的产量损失及其模型预测

THE MODELS TO PREDICT YIELD LOSS OF SOYBEAN CAUSED BY SOYBEAN MOSAIC VIRUS EPIDEMICS

网室接种和田间调查测定SMV引致大豆的产量损失证明,SMV侵染大豆植株愈是在生育早期产量损失愈重。盛花期以后发病的植株产量损失显著减小,鼓粒初期的病株几乎无产量损失。SMV不同毒株引致的产量损失显著不同,强毒株的侵染,引致感病品种的产量损失平均超过弱毒株的40％。根据不同初侵染水平的30组SMV流行与产量损失数据,采用逐步回归分析,建立了准确度较高的产量损失预测多点模型和单点模型。根据损失测定,大豆盛花期的SMV病株率低于3％可控制SMV流行所造成的产量损失。

Experimental resuts from yield loss studies with inoculation of two isolates of soybean mosaic virus in net cage, and with in vestigation of infection in epidemic field plots indicated that during early vegetative development of soybean plants, thinfection of SMV caused more serious losses than the infection after flowering beginning. After podding stage, the infection of SMV caused nearly no yield loss in the fields.The infection of the severe and mild isolates of SMV resulted in different yield loss signif-cantly. The severe isolate(83-02) caused 40% loss more than that of the mild isolate (83 -03).According to the analysis of conrrelation between the disease incidences during the various growing stages of soybean and yield losses of 30 group data, the disease incidences of 5 growing stages were used for stepwise regression calculation As a results, two predicting models of multiple- point and single - point for the yield losses of five susceptible soybean cultivars were obtained. The models were examined with 8 group data of actual yield losses other than in the setablishment of the models, good fittingness were observed between the actual and theoretical values. Through X2 - test, the above conclusion was also obtained. If the disease incidence was controlled to less than 3% after flowering stage, he yield loss caused by SMV could be controlled. The predicting models of yield loss would be benefitial to make the decision in disease management.