摘要
Morphological traits, anatomical features, chemical components and bending stress in the stems of three genotypes of wheat (Triticum aestivum L.), namely Xiaoyan54, 8602 and Xiaoyan81, were ex- amined by means of light microscopy coupled with Fourier transform infrared spectroscopy (FTIR). No- ticeable changes in morphological and anatomical traits were observed, including outer radius of stem, the ratio of stem outer radius to stem wall thickness, various tissue proportions and variations among dif- ferent types of vascular bundles. The results of chemical analysis revealed that Xiaoyan81 had the highest cellulose content in comparison with Xiao- yan54 and 8602, whereas lignin level in Xiaoyan81 was lower than that in 8602 but higher that that in Xiaoyan54. Bending stress analysis demonstrated that Xiaoyan81 may be the main target for identifica- tion, for it had the highest bending stress among the stems of three genotypes. Associated with bending stress, all the results presented here suggested that the ratio of stem wall thickness to its outer radius, schlerenchyma tissue proportion, the average num- ber of big VB per unit and the cellulose content are four important factors affecting the mechanical strength of Xiaoyan81 wheat stems, which can be considered as the key parameters for selecting varie- ties with bending stress. Therefore, it was suggested that in the selection of lodging resistant cultivars one should consider those characterized with large ratio of outer radius of stem to stem wall thickness, great-erschlerenchyma tissue proportion, high average number of big VB per unit with high cellulose content in their stems.
Morphological traits, anatomical features, chemical components and bending stress in the stems of three genotypes of wheat （Triticum aestivum L.）, namely Xiaoyan 54, 8602 and Xiaoyan81, were examined by means of light microscopy coupled with Fourier transform infrared spectroscopy （FTIR）. Noticeable changes in morphological and anatomical traits were observed, including outer radius of stem, the ratio of stem outer radius to stem wall thickness, various tissue proportions and variations among different types of vascular bundles. The results of chemical analysis revealed that Xiaoyan81 had the highest cellulose content in comparison with Xiaoyan54 and 8602, whereas lignin level in Xiaoyan81 was lower than that in 8602 but higher that that in Xiaoyan54. Bending stress analysis demonstrated that Xiaoyan81 may be the main target for identification, for it had the highest bending stress among the stems of three genotypes. Associated with bending stress, all the results presented here suggested that the ratio of stem wall thickness to its outer radius, schlerenchyma tissue proportion, the average number of big VB per unit and the cellulose content are four important factors affecting the mechanical strength of Xiaoyan81 wheat stems, which can be considered as the key parameters for selecting varieties with bending stress. Therefore, it was suggested that in the selection of lodging resistant cultivars one should consider those characterized with large ratio of outer radius of stem to stem wall thickness, greaterschlerenchyma tissue proportion, high average number of big VB per unit with high cellulose content in their stems.
基金
supported by the National Natural Science Foundation of China(Grant No.30330390)
National Science Fund of China for Distinguished Young Scholars(Grant No.30225005).
关键词
弯曲应力
小麦
茎
维管束
纤维素
木质素
wheat, stem, vascular bundles, cellulose, lignin, bending stress.
