【作者】 白志英；

【导师】 李存东； 张凤路；

【作者基本信息】 河北农业大学 ， 作物栽培学与耕作学， 2007， 博士

【摘要】 小麦代换系是遗传研究和育种的宝贵资源,开发利用小麦代换系对小麦抗旱育种具有重要意义。本试验以小麦中国春-Synthetic 6x 21个代换系及其亲本为材料,通过设置不同水分处理,采用形态观察、生理生化指标测定等方法,研究干旱胁迫对小麦代换系形态、生化及农艺性状的影响,并初步确定调控穗花发育及其相关性状的主效应染色体。主要研究结果如下:1.通过研究正常灌溉和干旱胁迫条件下不同小麦代换系和亲本的穗花分化过程,初步确定了延缓穗花分化进程的主效应基因可能位于Synthetic 6x的2B和7D染色体上;耐旱相关基因可能位于2D染色体上。2.通过测定不同处理条件下小麦代换系及其亲本叶片的生理、生化指标,结果表明干旱胁迫导致相对含水量、蛋白质含量、叶绿素及类胡萝卜素含量、光合速率、蒸腾速率降低,最大荧光(Fm)、PSⅡ原初光能转换效率(Fv/Fm)以及PSⅡ潜在活性(Fv/Fo)降低,却导致细胞膜透性增大、SOD和POD活性增强、脯氨酸和丙二醛含量增加、水分利用效率增加。在干旱胁迫条件下,Synthetic 6x的1D、2B、2D、3A、3D、4A、4B、6A、6B、7D和7A染色体上具有调控细胞膜稳定性的基因;1A、2D和3D染色体上可能存在调控相对含水量的基因,3A、3B、4B、5B、6B、1D、2D和4D染色体上可能存在调控离体失水速率的基因;5D和1D染色体上可能有促进脯氨酸积累的基因存在,4A、4B、2D和6D染色体上可能有抑制蛋白质含量下降的基因存在;2B和7D染色体上可能存在诱导SOD活性增强的有利基因,1A、2A和2D染色体上可能存在诱导POD活性增强的有利基因;7A和1D、7D染色体上可能存在抑制MDA含量增高的基因:3A和4D染色体上可能存在诱导叶绿素含量增高、光合速率及水分利用效率增高的有利基因,2A和4D染色体上可能存在诱导类胡萝卜素含量增高的有利基因;7B染色体上可能存在诱导蒸腾速率增强的有利基因;3A染色体上可能存在调控调控Fo的基因,4D染色体上可能存在调控Fm的基因,3A和7A染色体上可能存在调控Fv/Fm及Fv/Fo的有利基因。3.通过测定不同处理条件下小麦代换系及其亲本的农艺性状,表明干旱胁迫抑制了株高、穗长、穗下节间、单穗粒重、千粒重和单穗粒数增长。在干旱胁迫下,Synthetic 6x的1A、5A、6A、1D、2D、3D、4D、6D和7D染色体上可能存在调控株高的基因;1A、4A、6A、7A、1B、2B、4B、6B、7B、2D、3D、5D、6D和7D这15染色体上可能存在调控穗长的基因;1A、3A、6A、7A、2B和2D染色体上可能存在调控穗下节间长度的基因;1A、5A、2B、2D和5D染色体上可能存在调控单穗粒重的基因;1A、5A、2B、2D、3B、3D和6D染色体上可能存在调控千粒重的基因;5A、7A、7B、2D、3D、5D和7D染色体上可能存在调控单穗粒数的基因。4.利用主成分分析法对小麦代换系及其亲本的形态及生理生化指标的抗旱系数(DRC)进行分析和综合评价,将21个单项生理指标综合成为7个相互独立的综合指标。通过聚类分析,将小麦代换系及其亲本划分为3类:2D代换系及其父本Synthetic6x属高度抗旱类型;1A、3A、4A、6A、7A、2B、4B、6B、1D、3D、4D、7D代换系属中度抗旱类型;其余8个代换系(2A、5A、1B、3B、5B、7B、5D、6D)以及中国春属不抗旱类型。5.利用透射电镜观察不同代换系旗叶的超微结构,父本Synthetic 6x与2D代换系对水分变化不够敏感,与对照相比结构变化较小,表明二者抗旱性较强。而母本中国春与5D代换系对干早胁迫敏感,与对照相比结构变化较大,表明二者抗旱性较差。更多还原

【Abstract】 Wheat substitution lines are the valuable resources of genetic research and breeding. It is very important to exploit and utilize wheat substitution lines in drought resistance breeding. Chinese Spring (CS)-Synthetic 6x substitution lines and parents were used to study the effect on morphological characters, physiological and biochemical indexes and to determine the main effect chromosomes controlling spikelet progress and correlated indexes by observing morphological structure and measuring indexes under drought stress. The main results were as follows:1. A series of spikelet differentiation progress of Chinese Spring (CS)-Synthetic 6x substitution lines and parents under different water treatments were observed to determine the main chromosomes controlling spikelet differentiation progress. The result indicated that the genes inhibiting spikelet differentiation may be located on 2B and 7D chromosomes and that of drought tolerance may be located on 2D chromosome.2. The physiological and biochemical indexes of Chinese Spring (CS)-Synthetic 6x substitution lines and parents were measured to study the effect on correlated characters. The results showed that drought stress resulted in reduction of relative water content, protein content, chlorophyll content, corticoid content, net photosynthetic rate, transpiration rate, Fm, Fv/Fm, Fv/Fo and accumulation of proline content, SOD activity, POD activity, MDA content, water use efficiency.Under drought stress, the chromosomes 1D, 2D, 2B, 3A, 3D, 4A, 4B, 6A, 6B, 7D and 7A of Synthetic 6x were associated with membrane stability; the genes regulating RWC and RWL may be located on 1A, 2D, 3D and 3A, 3B, 4B, 5B, 6B, 1D, 2D, 4D chromosomes respectively; 1D, 5D chromosomes may associate with the proline accumulation and the 4A, 4B, 2D, 6D chromosome may associate with the protein reduction; the genes regulating SOD and POD activity may be located on 2B, 7D and 1 A, 2A, 2D chromosomes respectively, the genes of inhabiting MDA content may be located on 7A, 1D, 7D chromosomes; the genes regulating chlorophyll and corticoid content may be located on 3A, 4D and 2A,4D chromosomes, respectively; the genes of regulating high photosynthesis may be located on 3 A and 4D chromosomes, the genes of regulating high transpiration rate may be located on 7B chromosome, the genes of regulating high water use efficiency may be located on 3A and 4D chromosomes; the genes of regulating Fo may be located on 3A chromosome, the genes of regulating Fm may be located on 4D chromosome, the genes of regulating Fv/Fm and Fv/Fo may be located on 3A and 7A chromosomes.3. The agricultural traits of Chinese Spring (CS) - Synthetic 6x substitution lines as well as parents under the control and drought conditions were measured. The results indicated that drought stress resulted in reduction of plant height, spikelet length and so on.The results also indicated the genes of controlling plant height may be located on 1A, 5A, 6A, 1D, 2D, 3D, 4D, 6D and 7D chromosomes; 1A, 4A, 6A, 7A, 1B, 2B, 4B, 6B, 7B, 2D, 3D, 5D, 6D and 7D chromosomes may associate with spikelet length; 1 A,3A, 6A, 7A, 2B and 2D chromosomes may associate with controlling internode length; 1 A, 5A, 2B, 2D and 5D chromosomes may associate with controlling grain weight per spike; 1 A, 5A, 2B, 3B, 2D 3D and 6D chromosomes may associate with controlling 1000-grain weight; 5A, 7A, 7B, 2D, 3D, 5D and 7D chromosomes may associate with controlling kernel number per spike4. The drought comprehensive resistance of DRC of physiological, biochemical indexes and agricultural traits of Chinese Spring (CS) - Synthetic 6x substitution lines as well as parents was evaluated by principal components analysis. The results showed that the 21 single indexes could be classified into 7 independent comprehensive components. The cluster analysis was used to divide 21 substitution lines and parents into three kinds of drought resistance type. That was that: 2D substitution line and Synthetic 6x belonged to high drought resistance type; 1A, 3A, 4A, 6A, 7A, 2B, 4B, 6B, 1D, 3D, 4D, 7D substitution lines belonged to middle drought resistance type; 2A, 5A, 1B, 3B, 5B, 7B, 5D, 6D substitution lines and Chinese Spring belonged to poor drought resistance type.5 The differences of cell ultra-structure of flags leaves in two wheat substitution lines and parents under drought stress were investigated. The results showed the ultra-structure of flags leaves of 2D substitution line and Synthetic 6x with strong drought resistant were less affected than 5D substitution line and Chinese Spring with weak drought resistant under drought stress.更多还原