不同小麦品种茎秆抗倒性的研究

Study on the Stem Lodging Resistance of Different Wheat Varieties

为了明确影响小麦抗倒伏性的主要因素,选用生产中应用较广泛的6个高产小麦品种,采用田间试验与实验室分析相结合的方法,对不同品种的抗倒伏性状进行研究。结果表明,百农矮抗58的倒伏指数较小,为0.432,与其他品种相比差异显著;百农矮抗58的茎秆机械强度大、茎秆基部第二节短粗、秆壁较厚、次生根数量较多、株高和重心高度较低。相关分析表明,倒伏指数与第二节关系密切,第二节机械强度越大、壁越厚、干重越大、地下部根量越多,倒伏指数就越小,茎秆抗倒性就越强;适当降低株高可以降低植株的重心高度,增强植株抗倒能力。逐步回归分析表明,影响茎秆抗倒性的直接因子为茎秆基部第二节机械强度、第二节干重、地下部根量及地上部鲜重,其中第二节机械强度对茎秆倒伏指数的直接作用最大,其直接通径系数为-0.775,可用第二节机械强度的大小评价品种茎秆抗倒性的强弱。

Six high-yield wheat varieties widely applicated in production were selected,to investigate the lodging resistance of different varieties comprehensively,by combining field and laboratory methods.The results showed that the lodging index of Bainong AK 58 was smaller as 0.432,and which was significant difference with others.The research found that the stem mechanical strength of Bainong AK58 was larger,its second internode was shorter and thicker,and its culm wall was thicker,as the secondary root number was more,and its plant height and height of center of gravity were lower than others.Correlation analysis showed that lodging index had close relationship with the characteristics of second stem,the thickness of second section of the mechanical strength,the thickness of culm wall,the dry-matter weight of second stem and the root numbers,which were the main determinants of the lodging resistance.Therefore,reducing the plant height appropriately could reduce the gravity height of plant,and enhance the capability of plant lodging resistance.Stepwise regression analysis showed that the direct factors influencing lodging resistance were the mechanical strength of second stem,the dry-matter weight of second stem,the root numbers and the fresh plant weight of above ground,the most direct action on stem lodging index were the mechanical strength of the second stem with the direct path coefficient of-0.775.So,the stem lodging resistance strength of wheat varieties could be evaluated through the mechanical strength of second stem.