改良倒伏指数法鉴定小麦品种抗倒性初步研究

由于小麦茎秆基部弹性容易测定，因而本研究用其替换茎秆基部机械强度，对王勇等（1997）提出的倒伏指数进行改进。为验证这种方法的应用效果，以47个河南省区域试验小麦新品系及自育品系为试验材料，通过对小麦茎秆特性进行分析，结合多试点抗倒性验证，应用改良倒伏指数法对小麦抗倒伏能力进行初步鉴定。结果表明，从灌浆中期到灌浆后期，小麦基部茎秆弹性总体处于下降趋势，但仍有22.3%的品系基部茎秆弹性呈上升趋势，72.3%的品系倒伏指数有所下降，说明大部分小麦品系在灌浆后期的抗倒伏能力相对于灌浆中期有所上升。经相关性分析，节间充实度、长度、干重、重心高度、地上部鲜重、茎秆基部节间弹性等特性均与小麦抗倒性有关，其中，茎秆基部第一、第二节间充实度、长度、基部茎秆弹性与抗到性关系最为密切。在灌浆中后期，倒伏指数与倒伏点率、严重倒伏点率、平均相对倒伏面积、平均倒伏级及乔春贵等（1988）的方法计算得到的倒伏指数均呈正相关，以灌浆中期相关性较高。说明应用改良的倒伏指数衡量小麦品种抗倒伏能力是可行的，且在灌浆中期准确度更高。

Preliminary Study on the Improved Lodging Index Method for Identifying the Resistance of Wheat Varieties

Lodging is a very important trait for maintaining a high potential grain yield in bread wheat breeding, which is complicated with stem traits, plant height, environment, management and so on.How to find a simple, convenient and accurate method to predict lodging happening is the key aim for geneticists, breeders and physiologists.The study was conducted to provide a convenient and quick appraisal method for lodging resistance of wheat.The stalk characters of 47 winter wheat varieties (lines), sampled from wheat region test in Henan province were detected.A new method of lodging index was verified with more pilot regional tests.Results showed that the basal stem flexibility of most varieties were declined from the middle or later grain-filling stage to dough stage, but 22.3% of the total varieties were ascended.The lodging index of 72.3% of the total varieties was declined from the same stage, indicating that the lodging resistance of most wheat varieties at the dough stage were better compared with that at the middle or later grain-filling stage.Results of correlation analysis showed that center of gravity height, fresh weight of above ground, basal stem flexibility and stem node traits including length, dry weight and plumpness, were associated with lodging resistance, especially for basal stem flexibility.The correlations between basal stem flexibility and lodging resistance were significant.