品种布局防治小麦条锈病的模拟研究

 用小麦条锈病大区流行模型PANCRIN进行的模拟试验结果指出:抗病品种的合理布局能有效地延缓和减轻抗病性丧失,但其效果易受品种面积、流行速率和越夏区面积浮动的影响。布局策略上首先要按照小麦条锈病菌越夏途径中不同成熟期的麦田进行细致的布局,也就是布局要和"打越夏"结合,效果才更显著。其次要控制每个抗病品种的面积而增多抗病品种的数目,在所用模型规定的条件下,每一抗病品种的种植面积百分比不可超过15%,抗病品种总数争取≥ 6个。此外,要尽量压缩感病品种面积,减少大区流行菌量,感病品种面积最好不超过10%。流行系统的定量控制是个极其复杂的问题,因此上述初步结果只能供作研究参考,还不能视为应用指标。合理布局的设计应以深入掌握越夏规律为基础,这需要进一步开展有关研究。目前情况下,生产上尽量增多抗病品种数目,只要上下游品种雷同的不多,也能多少延长抗病品种的使用年限。

Simulation study on cultivar deployment against Wheat stripe rust caused by Puccinia striiformis West.in China

The effect of cultivar deployment for resistance against stripe rust in China was studied with the model PANCRIN. Simulation results showed that the break-down of resistance might be consi-derably delayed with a proper cultivar deployment. However, this delay may also be affected by several factors, such as the area of different resistant cultivars, pathogen infection rate and fluctuation of wheat-planting area in the regions where the pathogen oversummers. Development of cultivar deployment strategy should be based on consideration of the variation in wheat maturity in the regions where the pathogen oversummers, namely, the cultivar deployment should consider the wheat maturity as detailed as on a field scale. The wheat-planting area of each resistant cultivar should be optimized, and the number of resistant cultivars should be increased. Under the conditions the model used, the maximum percentage of planting area for each resistant cultivar is suggested to be <15%, and the number of resistant cultivars should be ≥ 6. In order to minimize the inoculum potential of disease pandemics, the areas of the universally susceptible cultivars is suggested to be limited to less than 10%. The figures suggested above are for reference only and can not yet be used as control index because the system concerned is very complicated. The strategy for deployment should be further developed based on the fully understanding of the pathogen oversummering process and patterns. Under the current production situation, increasing and using as many resistant cultivars as possible is still suggested to manage the disease. As long as not many same resistant cultivars are used in both upper and lower reaches regions of the pandemic system, the lifetime of resistance in these cultivars could be prolonged.