玉米常用自交系茎节抗折强度分析

通过采用新的玉米茎节抗折强度测定方法，研究了23个玉米常用自交系的茎节抗折强度及其与株高、穗位高、去鞘茎粗、带鞘茎粗及叶鞘厚度等性状的相关关系。结果表明：抽雄后6 d不同自交系间茎节抗折强度呈现极显著差异；抽雄后6 d带鞘茎节抗折强度与株高、穗位高及地上第3节茎粗显著不相关，而与折断处去鞘茎粗、带鞘茎粗和叶鞘厚度呈极显著正相关。通径分析表明，抽雄后6 d带鞘茎节抗折强度受折断处带鞘茎粗的直接影响，去鞘茎粗和叶鞘厚度对带鞘节抗折强度的影响是通过其对带鞘茎粗的直接作用而间接实现。抽雄后6 d的叶鞘贡献率要高于抽雄后15 d，6 d时叶鞘贡献率的变异幅度较大；带鞘茎节抗折强度的变异幅度低于去鞘茎节抗折强度。育种上抗茎折材料的选择应注重穗位以上茎节粗度及叶鞘厚度两个性状。

The Study of the Stalk Lateral Breaking Strength on Maize Inbred Lines

With the use of a new measurement method for stalk lateral breaking strength(SLBS), we studied SLBS and correlative characters of 23 inbred lines. The results showed that there were difference in significant level between inbred lines during 6 days after tassel. The SLBS showed no relationship on significant level with plant height, ear height and the third stem diameter, but significant relationship with node diameter without sheath, node diameter with sheath and sheath thickness, Path analysis showed that the SLBS was primarily influenced by node diameter with sheath, and the effect of node diameter without sheath and sheath thickness on SLBS can be indirectly actualized via node diameter with sheath. Thick sheath might improve the breaking strength effectively. Breeders should pay attention to the stem diameter of both basal stem and the one above the ear.