抗倒伏甘蓝型油菜(Brassica napus L.)根和茎解剖学结构分析

摘要

对甘蓝型油菜(Brassica napus L.)6个抗倒伏材料和5个易倒伏材料的苗期和苔期的根部和茎部采用石蜡切片的方法切出6 μm厚的薄片,用番红-固绿双重染色,借助Olympus显微镜观察不同材料茎的表皮、皮层、厚角组织、维管束和髓的结构,以及根的木质部、导管等,并对茎和根的结构特点进行了比较.结果表明:①在苗期的茎中,与易倒伏材料相比,抗倒伏材料有较多的厚角组织;抗倒伏材料维管束的面积占茎基部横切面面积之比比易倒伏材料平均高13.1个百分点;抗倒伏材料和易倒伏材料间维管束的个数差异不大,但抗倒伏材料的维管束排列相对比较紧密.②在苔期的茎中,抗倒伏材料的厚角组织和厚壁组织比易倒伏材料发达;虽然两者间维管束的个数和面积无明显差异,但抗倒伏材料维管束排列紧密.③在苗期的根部,抗倒伏材料和易倒伏材料木质部的面积占根部横切面面积之比差异不显著;但抗倒伏材料导管数目比易倒伏材料平均多74.7个,易倒伏材料中较大导管的数目多于抗倒伏材料.④在苔期的根部,抗倒伏材料木质部占根横切面面积的之比比易倒伏材料高8.33个百分点,抗倒伏材料单位面积导管的数目多于易倒伏材料.因此,较多的厚角组织和厚壁组织、较多的导管数和排列紧密的维管束是甘蓝型油菜抗倒伏材料苗期和苔期重要的解剖学特点.%A comparison of anatomical structures of stems and roots, sampled at seedling and bolting stage, was made between lodging resistant( six lines) and susceptible lines ( five lines) in Brassica napus L. by applying paraffin and safranine-fast green double stain method. Results showed that :①More collenchyma tissue was developed in the stem of resistant lines at seedling stage compared to susceptible ones. Anatomical structure of the resistant line was characterized with larger vascular area in stem base. The ratio of vascular areas to the total areas of stem base cross section of resistant lines gave 13. 1％ higher than that in susceptible one. The number of vascular bundles had no difference between resistant and susceptible lines. However the vascular bundles were more closely arranged in resistant lines compared to the susceptible ones.②More collenchyma and sclerenchyma tissue were formed in the stem of resistant lines at bolting stage. No difference was shown in the number of vascular bundles and the percentage of vascular areas between resistant and susceptible lines. A close arrangement of the vascular hundles was only observed in resistant lines at bolting stage.③ There was no difference in the ratio of xylem areas to the total cross section areas of root between resistant and susceptible lines at seedling stage. Average number of vessels in the root of resistant lines was 74. 7 more than that in susceptible lines, while the number of larger vessels in susceptible lines was more than that in resistant lines. ④ The ratio of xylem areas to the total cross section areas of root at bolting stage gave 8. 33％ higher in resistant lines than that in susceptible ones, and the number of vessels in resistant lines was higher than that in susceptible lines.