Studies Of Stem Structure, Cell Wall Components And Fast-screening Method On Lodging Resistance Wheat

Wheat (Triticum aestivum L.) is a very important crop in our nation even in the world as it used for human food. High yield varieties have also resulted in increased stem lodging. Therefore, a more thorough investigation of high lodging resistance nature of high yield characterizes cultivar stem is needed. Morphological traits, anatomical features, chemical components and bending stress in the stems of three genotypes of wheat, namely Xiaoyan54, 8602 and Xiaoyan81, were examined by means of fluorescent microscopy coupled with Fourier transform infrared spectroscopy (FTIR). 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 vascular bundles (VB) per unit and the cellulose content are four important factors affecting the high bending stress 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, greater schlerenchyma tissue proportion, and high average number of big VB per unit with high cellulose content in their stems. The second investigation aimed at exploring the rapid quality analysis of high lodging resistance wheat cultivar by FTIR, complemented by multivariate analysis such as principal component analysis (PCA) and cluster analysis. The results of FTIR coupled with PCA revealed that developmental internodes of wheat stem could distributed from lower internodes to higher internodes along PC2 loading, which was consistent with polysaccharides and proteins in the cell wall. Furthermore, from the FTIR complemented by PCA and cluster analysis, two distinct populations of stems also could be identified by spectral features that were related to stem bending stress. The main cell wall component responsible for these differences was polysaccharide and protein. Therefore, it was suggested that the combination with multivariate analysis together with FTIR could help resolve the questions highlighted in this study and the application of these methods to a much wider range of cultivars of unknown bending stress promises to be of interest.