水稻细胞质雄性不育系和保持系表型观察及活性氧代谢研究

【作者】 刘莉；

【导师】 陈国祥；

【作者基本信息】 南京师范大学 ， 植物学， 2016， 硕士

【摘要】 植物细胞质雄性不育(CMS)具有重要的杂种优势利用价值。本研究以新育成的野败型优质籼稻三系不育系天丰A及其保持系天丰B为实验材料,首先从植株主要形态特征方面观察不育系与保持系之间的表型差异,以探究不育所造成的诸多形态变化,其次从生理生化角度研究了水稻不育系和保持系花药和叶片发育过程中活性氧代谢和相关抗氧化酶活性动态变化差异,以探讨水稻细胞质雄性不育的生理机制。该研究旨在为水稻不育的可能机制及其选育和生产应用提供理论依据,对于将来利用水稻细胞质雄性不育系培育杂种植株具有重要的指导意义。研究结果如下：1.不育系天丰A与保持系天丰B的株高、剑叶长宽都没有显著差异,但不育植株的始穗期比保持系延迟,不育性对穗长、单株穗数、每穗颖花数、颖花形态、花药形态均有影响,说明植株营养体对不育性造成的不利影响具有较大的抗性,而生殖器官及其附属组织对不育性造成的不利影响具有较弱的抗性,使整个植株在稻穗、颖花、花药形态方面与可育系相比表现出明显的差异。另外,可能由于发育过程中雄性不育植株的生理代谢发生异常,致使营养器官向生殖器官输送营养物质的过程不能顺利进行,最后导致营养期的生长延长,而生殖期的生长发育推迟。根据花粉育性鉴定的结果,不育系花粉对I2-KI反应几乎不着色,且在扫描电镜下观察到不育系花粉呈瘪三角形或不规则的多边形,说明可能是花粉发育过程中代谢异常,使花粉中内含物空缺,营养物质供应不足,导致花粉变形,最终造成雄性不育。2.不育系花药天丰A中O2产生速率、H202和MDA含量总体高于保持系天丰B,抗氧化酶CAT活性总体低于保持系,而POD活性始终比保持系花药高。说明不育系花药发育过程中O2-、H2O2代谢异常,MDA积累过多,抗氧化物保护酶SOD、CAT活力下降,引起活性氧自由基的产生与清除代谢失调,同时活性不断上升的POD酶,有可能使IAA大量氧化降解,导致花药发育过程中IAA缺失,营养代谢失调、物质能量亏损,这些因素相互作用可能是导致雄性不育的重要原因。3.对花药各发育时期相应的叶片进行研究,发现水稻不育系天丰A与保持系天丰B活性氧代谢差异在叶片中也有所表现,两系叶片中的H2O2、MDA含量和CAT活性存在显著差异,但其叶片表型无明显差异,可能是由于生长发育过程中花药内部的生理代谢反应比较激烈,细胞质雄性不育引发的活性氧代谢异常造成的生理毒害作用主要表现在活跃组织中,所以活性氧代谢异常造成的生理毒害在花药中表现的更明显。也进一步证实雄性不育可能是由于不同组织或器官对活性氧伤害的忍受能力不同造成的。更多还原

【Abstract】 Plant cytoplasmic male sterility (CMS) has important value in heterosis utilization. In this study, Tianfeng A of a new wild abortive indica CMS line and its maintainer line Tianfeng B were employed as experimental materials. At first phenotypic differences between CMS line and maintainer line were observed to explore the many morphological changes caused by infertility. Secondly dynamic change differences of active oxygen metabolism and related antioxidant enzymes activity in anthers and leaves from CMS line and maintainer line were studied in the development process to investigate physiological mechanisms of the cytoplasmic male sterile rice. This study aimed to provide a theoretical basis for possible mechanisms of rice infertility and its breeding and production applications, which will have important guiding significance for rice hybrid breeding by using cytoplasmic male sterile line in the future. The results are as follows:1. plant height, length and width of flag leaves between CMS line Tianfeng A and maintainer line Tianfeng B were not significantly different, but heading stage of CMS line was later than that of the maintainer line and panicle length, panicles per plant, spikelets per panicle, spikelets shape, anthers shape were affected by sterility, which indicated that the ability of reproductive organs and its affiliated organizations to resist the adverse effects caused sterility was less than that of phytomas, so that panicles, spikelets and anthers of CMS line plants exhibited significant differences compared with that of fertile lines. In addition, it is possible that abnormal physiological metabolism of male sterile plants make the delivery of nutrients can not be carried out smoothly during the development process, and finally lead to the growth of vegetative period extended and development of reproductive period is delayed. Pollens of male sterile line can not stained with I2-KI solution and were in flat triangles or irregular polygons by scanning electron microscope, which indicated that abnormal metabolism in the process of pollen development may cause the lack of nutrient supply, so that the pollen was out of shape, and ultimately cause male sterility.2. Anthers of CMS line Tianfeng A had higher production rate of O2-, contents of H2O2 and MDA, in comparison with the maintainer line Tianfeng B. The activities of SOD and CAT were obsessively lower in CMS anthers, whereas POD activity of CMS anthers was higher than those of maintainer line. Based on the above results, abnormal metabolism of O2- and H2O2, excessive accumulation of MDA and decline of SOD and CAT activities in the process of CMS anthers development made production and scavenging of reactive oxygen species disordered. Meanwhile rising activity of POD may cause substantial degradation of IAA, which lead to lack of IAA, imbalance of nutritional metabolism, loss of physical energy during anthers development. The interaction of these factors may be an important cause of male infertility.3. Investigation of the leaves on corresponding period found differences of active oxygen metabolism between CMS line Tianfeng A and maintainer line Tianfeng B were also reflected in the leaves. Contents of H2O2 and MDA and activity of CAT in leaves of the two materials was significantly different, but the leaves had no obvious phenotypic differences. The reason may be that physiological metabolic reactions inside anther is fierce in the process of growth and development and that physiological toxicity of abnormal reactive oxygen metabolism caused by cytoplasmic male sterility mainly manifest in the active organization, so the physiological toxicity caused by the abnormal metabolism of reactive oxygen species is more obvious in the anther. It is also further confirmed that the male sterility may be caused by differences in the ability of different tissues or organs to tolerate the injury of reactive oxygen species.更多还原