为了比较不同春玉米品种的节折强度,以冀西北寒旱区9个春玉米品种为研究对象,通过测定玉米基部第三节抗折强度,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分析,研究春玉米节折强度与茎秆显微结构之间的关系。结果表明：不同春玉米品种间节折强度达显著水平；对各品种维管束显微指标进行统计分析表明,维管束鞘厚度和表皮细胞厚度变异系数最大,分别达到34.8%和23.2%；茎节维管束数目增多不利于节折强度的提高(r=-0.945**,r=-0.927**),维管束平均面积、韧皮部面积增大有利于节折强度的增加(r=0.831*,r=0.799*；r=0.733*,r=0.786*)。通径分析表明,维管束数目对节折强度的直接效应最大,表皮细胞厚度次之,维管束最大面积、维管束鞘厚度、韧皮部面积等指标也通过维管束数目对茎折强度起间接作用。参试品种中,京农科728、纪元108维管束数目较少,维管束平均面积、韧皮部面积较大,茎折强度较高,抗倒伏性优于其他品种。
英文摘要:
In order to compare different section folding strength of spring maize varieties, in cold and arid regions of northwest 9 spring maize varieties as the research object, through the determination of corn base in the third section flexural strength, microstructure and by using optical microscope to observe the internodes, section microscopic indicators of vascular bundle and folding strength related analysis, research section of spring corn folding strength and stem the relationship between the microstructure. The results showed that the joint folding strength of different spring maize varieties reached a significant level. The statistical analysis on the microscopic indexes of vascular bundles showed that the variation coefficient of vascular bundle sheath thickness and epidermal cell thickness was the largest, reaching 34.8% and 23.2% respectively. The increase of the number of vascular bundles in stem segment was not conducive to the improvement of the nodule folding strength (r=-0.945**, r=-0.927**), while the increase of the mean area of vascular bundles and phloem area was beneficial to the increase of the nodule folding strength (r=0.831*, r=0.799*, r =0.733*, r=0.786*).Diameter analysis showed that the number of vascular bundles had the largest direct effect on the strength of the stem folding, followed by the thickness of epidermal cells, and the largest area of vascular bundles, the thickness of vascular bundle sheath, phloem area and other indicators also had an indirect effect on the strength of stem folding through the number of vascular bundles. Among the tested varieties, the number of vascular bundles was less, the average area of vascular bundles and phloem area were larger, the stalk folding strength was higher, and the lodging resistance was better than other varieties.
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