通过测定黄淮海地区22个常用玉米自交系的玉米茎节抗折强度(节折强度,NSS),并利用光学显微镜观察其茎节显微结构,对维管束各项显微指标与节折强度进行相关及通径分析,研究玉米节折强度与茎秆显微结构之间的关系。结果表明,不同自交系间节折强度差异达显著或极显著水平;对各自交系维管束显微指标进行统计分析表明,单个维管束面积的变异系数最大,为25.06%,其次是维管束数目,为19.97%;茎节维管束数目增多不利于节折强度的提高(r=-0.54**,r=-0.55**),单个维管束面积增大有助于节折强度的提高(r= 0.48*,r=0.43*)。通径分析表明,抽雄后6 d及15 d两个测定时期均为维管束个数对节折强度的直接效应最大,单个维管束面积效应次之;在花后6 d,维管束最小直径、平均直径等指标对于节折强度的贡献也主要通过维管束数目的间接效应起作用。

To identify the relation between node snap strength(NSS) and stalk microstructure, NSS of 22 maize inbred lines was measured and microstructure of vascular was observed through optical microscope. Based on the data, the correlation and path analysis between NSS and stalk microstructure was studied. The results showed that the NSS difference of inbred lines reached significant or extremely significant level. The variation coefficient of single vascular area, 25.06%, was maximal; which was followed by variation coefficient of vascular number, 19.97%. The increase of vascular number went against the enhancement of NSS(r=-0.54**, r=-0.55**), but the increase of vascular area contributed to the enhancement of NSS(r=0.48*, r=0.43*). Path analysis indicated the direct effect of vascular number to NSS was maximal followed by the muscular area at 6 days and 15 days after pollination. At 6 days after pollination, contributions of minimal diameter and average diameter of vascular affected NSS through the indirect affection of vascular number.

国家“863”课题(2006AA100103)、山东省农业科学院创新基金项目(2006YCX005)、山东省农业科学院博士基金项目(2006YBS020)