襄阳地区小麦条锈菌越冬潜伏菌源量与病情的关系研究

Study on relationship between the quantity of Puccinia striiformis f.sp.tritici in latent during overwinter and the disease index in Xiangyang area

在小麦条锈病菌(Puccinia striiformis f.sp.tritici,PST)越冬区的湖北襄阳、宜城和枣阳3个地区同一时间定点(GPS定位)采样,应用双重real-time PCR定量测定方法进行潜育侵染测定,并于春季在相应取样点进行病情调查。取样区域按照镇/区划分成不同的区域。每个区域的分子病情指数(MDI)和病情指数(DI)由该区域内所有样品和调查点数据取平均值得到。由MDI转换成风险指数(RI),并做RI与春季病情指数的相关性分析。同时,也通过坐标数据进行了空间分析。结果显示,PST潜伏侵染量与春季病情呈显著相关,并且两者均与其分布区域距汉江水系的距离相关。

Stripe rust, caused by Puccinia striiformis f. sp. tritici （PST）, is one of the most important wheat diseases worldwide. However, the relationship of latent PST in overwinter wheat leaves and the disease index （DI） of the next spring remains obscure. To address this issue, a systemic study with the combination of field sampling and DI investigation, molecular PST detection and correlation analysis was performed. Specially, in winter, sampling of wheat leaves was conducted simultaneously with GPS positioning in Xiangyang, Yicheng and Zaoyang, the overwinter regions of PST. Duplex real-time PCR was used to quantify the latent PST in the sampled leaves. In spring, disease investigations were conducted simultaneously in the same sampling positions. Sampling areas were divided into different districts based on town/suburb district. The MDI and DI of each dis- trict were obtained by calculating the average of all sampling and investigation points within the district. Each MDI of a district was converted to risk index （RI） by a formula, and then RI was calculated for correlation with DI. Meanwhile, spatial analyses were conducted based on coordinate data. The results showed that the quantities of PST in latent were significantly correlated with the disease in spring, and their distributions and degree of disease were highly correlated with the distance to the Han fiver.