选用抗病品种是防治稻瘟病的重要措施,品种的抗病性与品种的生理机制,代谢能力有密切关系。稻株体内如氮素偏多则易感病,利用淀粉与碘反应,速测稻株叶鞘淀粉含量作为水稻生长期间植株诊断的方法。在氮肥过量稻株生长过旺的情况下,一般易感稻瘟病,叶鞘淀粉含量也相对下降。采用叶鞘淀粉含量测定,作为预测稻瘟病发生轻重的方法曾获得一定的结果,如广西梧州地区测定抗病品种的叶鞘淀粉含量高,感病品种淀粉含量低。在水稻生长期间稻株叶鞘淀粉含量的多少,一定程度能反应稻瘟病的感病程度。为了解不同抗感反应品种的叶鞘淀 The selection of resistant varieties is an important measure to prevent and control rice blast. The disease resistance of varieties is closely related to the physiological mechanism and metabolic capacity of varieties. In rice, if the nitrogen is too much, it is susceptible to disease. Using the reaction of starch and iodine, the leaf starch content in rice leaves can be determined rapidly as the method of plant diagnosis during rice growth. In the case of excessive nitrogen fertilizer overgrowth, generally susceptible to rice blast, leaf sheath starch content is also relatively decreased. As the method of predicting the severity of rice blast, certain results have been obtained using the determination of starch content in leaf sheath. For example, the content of starch in leaf sheath and the starch content in susceptible varieties are low in Wuzhou area. During the rice growth stage, the amount of starch in the leaf sheath of the rice plant can reflect the degree of susceptibility to rice blast to a certain extent. In order to understand the different resistant varieties of leaf sheath precipitation