【作者】 朱蕾；

【导师】 施国新； 林金星；

【作者基本信息】 南京师范大学 ， 植物学， 2004， 硕士

【摘要】 小麦(Triticum asetivum L．)新品种“小偃81”，是由抗病虫害小麦品种“小偃54”和高产抗倒伏小麦品种“8602”杂交选育出的具有优良特性的后代。本文运用茎秆强度测定、显微结构测量、组织化学染色、激光共聚焦显微镜、原子力显微镜、透射电镜、傅里叶转换红外光谱、木质素含量测定等方法及氧电极等生理技术手段，对“小偃81”及其亲本“小偃54”和“8602”的茎秆生物学特性与抗倒伏的关系进行了较全面和系统的研究。此外，文中还对北京地区大面积种植的小麦品种“京411”的旗叶和芒的叶绿体的结构与光合活性作了比较。 研究结果表明：杂交新品种“小偃81”属于矮秆品种，其植株高度明显比对照亲本品种“小偃54”和“8602”矮。通过秆强测定器在实验田中测得的“小偃81”的抗倒伏力明显强于对照亲本。茎秆组织结构分析显示：与母本“小偃54”和父本“8602”相比，“小偃81”的茎秆直径变小、横切面上维管束数目减少，而茎秆壁厚比、横切面上机械组织比例却显著增大，单位面积上维管束数目增多。 细胞壁木质素分析表明：“小偃81”茎秆的细胞壁的Klason木质素含量高于其亲本；组织化学染色和激光共聚焦显微镜观察显示小麦茎秆中的木质素多分布于机械组织和维管束的纤维细胞壁；傅里叶转换红外光谱(FT-IR)分析表明小偃81的木质素特征基团含量高于亲本“小偃54”和“8602”，且成分多为紫丁香基(S型)木质素。 小麦茎秆纤维分析发现：与亲本对照相比，“小偃81”的纤维长度较短，长宽比较小；而纤维壁厚，胞腔小，壁腔比大，更坚硬，不易被外力打破原有的网状连接结构。傅里叶转换红外光谱分析显示：“小偃81”纤维素的C-H伸缩振动强于“小偃54”和“8602”。原子力显微镜观察到了小偃81茎秆的次生细胞壁上微纤丝的排列。 器官的衰老过程伴随着一系列的叶绿体和光合活性变化：器官衰老，光合活性降低，叶绿体数量减少。芒和旗叶的衰老都具有这些变化，只是芒似乎有一个滞后的时期，即当旗叶变黄并且放氧速率开始降低的时候，芒仍具有较高的光合活性。摘要 综上所述，与亲本“小僵54”和“8602”相比，杂交小麦新品种“小堰81”的茎秆的高度、解剖结构和细胞壁的木质素与纤维的含量和组成等茎秆的质量都更有利于抵抗风雨等外力的作用，从而减少倒伏的发生。对高产小麦品种“京411”的旗叶和芒的叶绿体发育过程的研究表明:芒对光合作用的贡献也不容忽视。更多还原

【Abstract】 The new wheat (Triticum asetivum L.) variety Xiaoyan 81, a comparatively lodging resistant cultivar, is a selected offspring from its maternal parent Xiaoyan 54 which is a commercial cultivar with good quality and broad adaptability and paternal parent 8602 which has a higher ratio of the grain-weight and high yield. The relationship of culm cytological features and lodging resistance was studied by means of various techniques, including culm strength determination, anatomical analysis, histochemical staining, confocal laser scanning microscopy (CLSM), atomic force microscopy (AFM), Fourier transfer infrared spectrometry (FT-IR) and Klason lignin determination. In addition, structural and functional changes in chloroplast of the flag leaf and the awn in cv. Jing 411 were investigated using transmission electron microscope (TEM) and oxygen electrode during series developmental stages.First of all, the prostrate tester was used for testing the culm strength of cv. xiaoyan 81 in comparison with its maternal parent cv. xiaoyan 54 and paternal parent cv. 8602 during the period from the milk stage to dough ripe stage. The result showed that the culm strength of cv. Xiaoyan 81 is stronger than cv. Xiaoyan 54 and cv. 8602.Subsequently, the culms of cv. Xiaoyan81 together with its maternal parent cv. Xiaoyan 54 and paternal parent cv. 8602 were compared at the morphological level to determine the anatomical features that were associated with these traits. This analysis revealed that the lodging resistant cv. Xiaoyan8l culms were shorter, possessed smaller diameter and thicker width, higher thickness-diameter ratio and higher percentage of mechanical tissue, less number of vascular bundles and more in unit area, compared with its parents.Furthermore, the lignin content determination according to Klason’s method revealed a much higher lignin content in the culm of cv. Xiaoyan8l than that in the cv. Xiaoyan 54 and cv. 8602. Semi-quantitative analysis of lignin with confocal laser scanning microscopy (CLSM) and histochemical staining indicated that lignin deposited in the cell wall of mechanical tissues and vascular bundles in cv. Xiaoyan 81. Fourier transfer infrared spectroscopy (FTIR) showed that the lignin characteristic units in cv. Xiaoyan 81 were higher than that of its parents, and cv. Xiaoyan 81 possessed much syringl units, which likely contributed much to lodging resistance.-3-Moreover, in contrast to its parents, cv. Xiaoyan 81 possessed shorter fiber and length-width ratio, thicker fiber wall, small pith and large fiber wall-pith ratio. Therefore, the fiber in cv. Xiaoyan 81 was hard and the original fiber net construction was not easy to break. FT-IR analysis showed that C-H flex oscillation of cellulose in cv. Xiaoyan 81 was stronger when comparing with its parents. And the cellulose microfibrils array in the cell secondary wall was captured using atomic force microscope.In addition, structural and functional changes in the awn and the flag leaf were studied. Awns are organs directly exposed to light but they contain more grana per chloroplast, bigger granal stacks and more thylakoids per grana] stacks. And non-leaf organs have fewer and smaller chloroplasts than leaves. In the meanwhile, studies on the rates of photosynthetic oxygen evolution of awns and flag leaves in wheat were carried out. It demonstrated that the photosynthetic contribution of non-leaf organs was 6%-28% of that of flag leaves. The decline in photosynthetic activity was closely related to the reduction of chloroplast numbers. Interestingly, it was observed that the photosynthetic capacity in the aging plant declined earlier in leaf organs than in non-leaf organs, which suggested that non-leaf organs were still functional in the later development stages, when leaves had been yellowish and exhausted.In the summary, all of these findings provided anatomical and chemical evidence for a better quality in biomechanics of culm in cv. XiaoyanSl than that in its parents. The awns contribute much to the photosynthesis as well as the leaf.更多还原