【作者】 陶龙兴；

【导师】 王熹； 张夫道；

【作者基本信息】 中国农业科学院 ， 植物营养学， 2003， 博士

【摘要】 目前在生产上应用的一些亚种间杂交组合，虽有穗大粒多、营养生长及生殖生长强的优势，却往往存在籽粒充实度较低或年度间结实不稳定的问题，成为困扰当今亚种间杂交稻选育研究和应用推广的主要因素。本论文选用亚种间杂交稻协优9308及其恢复系中恢9308为主试材料，辅以亚种间杂交稻协优9312、Ⅱ优162及其恢复系，研究了灌浆初期籽粒内源吲哚乙酸的变化，及其对籽粒灌浆结实的影响，同时，在论文研究过程中，对杂交稻籽粒内源吲哚乙酸的HPLC测定方法进行了改进。 1、建立了一套更适合水稻籽粒内源IAA测定的HPLC检测方法。本试验利用低温（-20℃）冻熔法去除粗提样品的大部分色素及杂质，采用Sep-Paks C₁₈柱、Oasis HLB小柱及0.45μm超滤膜（均为Waters公司产品）连续三步纯化技术，获得符合定量要求的回收率及测定结果。与传统方法相比，本方法免去了传统方法的多次样品萃取及浓缩的步骤，减少了检测物质在提取过程中的损失，提高了样品的重现性及回收率。 2、进一步验证了籽粒灌浆增重的粒间顶端优势。粒间顶端优势是水稻的普遍属性，杂交组合及其亲本的籽粒灌浆都存在“粒间顶端优势”的生理现象，即强势粒灌浆势对弱势粒灌浆的抑制现象。本研究进一步表明，各组合间籽粒增重的粒间顶端优势的强度有异，组合与其恢复系也存在差异。比之相应的恢复系，其组合的粒间顶端优势比恢复系行所放大。杂交组合强、弱势粒之间的粒间顶端优势现象，与其恢复系强、弱势粒之间的粒间顶端优势现象有一定程度的相关性。在本试验中，如果恢复系籽粒增重具有较强的粒间顶端优势，其组合往往也表现出较强的粒间顶端优势，反之亦然。 3、粒间顶端优势起始于籽粒糖份积累的差异。研究表明，无论是组合还是恢复系，其强势粒的糖份积累规律与弱势粒的糖份积累规律存在很大差异。在本试验中，强势粒中糖份含量受精后就快速升高，弱势粒糖份含量的上升总是滞后于强势粒。 钢人将林钢份的变化动态‘。几。断更系籽村的糖价变化动态h一人材)X的则似性，变化幅度比小时K更系他开放人。 此外，防打滑浆过厂的进行，就籽粒小 f【I可讲述精（初约精、计精读果糖）大局的比例而大，组合‘JL州…，快复系之间行人很人种旧的w似，叮，这种则似L八弱势粒卜表现尤为稳｝L；4、粒阳／加端优势起门十粒间内源IAA水十的共十。尤论足杂文组合应足相w的恢复系，水稻一镇小强势粒‘沾gy，’粒内源IA＊大本变化分＃，强科粒小响内源IAA食品从受精”＼人就开始卜门，随有灌浆的进行，内源IAA 卜升的速度加快，全受份)＊第9人，强势粒中内源IAA水个仍然表现出快速1：升趋势。受课后杂交组合的势粒小内源1＊A含既没有迅速表观山11升的趋势，这种“滞缓”状态一阿维持至受粘门第7大，这时弱势粒中内源1＊A含量才表现出较明显卜升的趋势，们在全受粮后第9大，弱势粒中的IAA含量仍明显低于强势粒。 与杂交组合相比，相应恢复系中强势粒内源IAA含量的上升速度低于问时期组合强势粒IAA含量的卜升速度，而弱势粒内源1＊A含一量的卜升速度高于同时期组合弱势粒IAA含量的卜升速度，恢复系弱势粒内源h 含量卜升的“滞缓”期也短十和)诽nft弱势粒M 含氯的“滞缓”期。巾此可见，比之相应的恢复系，其至交织合放大了强势粒对弱势粒的IAA水个优势。 人一试验中，杂交织合强、弱势粒之问的IAA优势现象，与其恢复系强、弱势粒之间的IAA优势现象有一定程度的扭头性，如果‘恢复系具行较强的粒饲IAA水一个优势，见细介件往也表现tJI较强的粒问！AA水。l‘优势。5、内源IAA足籽粒激浆的信，白、物质。灯光厂H刁＊A勺’比G山＊仍 在籽粒十家积的农工 和先后。问什素标L试验表u，人水稻籽＊灌浆初出］，籽粒中广光积累飞H一IAA，标记贮藏物质’H一G！noose的积累滞厂。 上次，（l）IAA运输抑市开 TIBA＊处I甲，降低厂等丰 卜’H＊ 的水卜；（2）IAA牛物合＊ 山抑开的处土 号通过抑i 2N一IAA 面物个人 的前体原＊ 工H一＊广人籽粒小的积累，降低’H一 ／籽粒小的水个；（3）I＊AN抑剂的处理，抑制 厂’N．彻萄糖人：籽 ＼粒中的积累，累积峰值也因为IAA阻抑剂的处理而降低，峰值出现的时间滞后。这种现象可能是IAA阻抑剂作用的二级效应，IAA阻抑剂的直接效果是导致籽粒中IAA水平的降低，使得葡萄糖在籽粒中的积累缺乏生理动力。 再次，外源IAA处理幼穗，对IAA诱导淀粉的积累有助动效应。高浓度外源IAA对幼穗的处理，使强、弱势粒中累积了较高水平的IAA，缩小了强势粒与弱势粒之间原来存在的IAA水平的差异，削弱了强势粒对弱势粒的“粒间顶端优势”，表现出强势粒的结实率有所下降，弱势粒的结实率明显上升，对整穗的结实率也有所提高。 由此可见，内源IAA对启动籽粒的灌浆起到重要的信息效应，信息出现的时间及强度与籽粒灌浆启动的时期及灌浆强度关系密切。外源IAA的处理，可以削弱强、更多还原

【Abstract】 Subspecies hybrid rice which are widely adopted in China show a strong superiorities in larger spike, more grain number and stronger growth potential, but a low seed setting rate of most combinations become a major obstacle in their application and extension. By setting up an IAA HPLC detection method, and application of isotopes and ELISA technique, the correlation of endogenous 1AA with the grain filling were studied in this thesis. Subspecies hybrid rice Xieyou9308 with its restorer Zhonghui9308 was tested as main material; Xieyou9312 and Hyou162 with their restorers were also planted and sampled in this experiment. The results are briefly described as follows.1. Purification and detection method of endogenous IAA in subspecies hybrid rice grains was improved and established. It is simplified and operable method when compared to the traditional one, and the released data is coincides with quantitative requirements.2. Further confirmation of the "Apical-grain superiority" in grain filling: It is a common phenomenon of apical-grain superiority in grain filling, but the differences were existed within combinations and restorers. There were some correlation between restorer and its hybrid rice, the apical-grain superiority in combination was amplified when comparing to its restorer.3. Carbohydrate accumulation in spikelets: Superior spikelets showed a privilege in easy access to accumulate the carbohydrate. The carbohydrate content in superior spikelets increased rapidly soon after pollination and reach the peak. Only then, the carbohydrate content in inferior spikelets began to accumulate. The combination and its restorer show a similar fluctuation pattern in carbohydrate accumulation. During grain filling period, the accumulating ratio of three kinds of sugar (Glucose/Sucrose/Fructose) in spikelets of restorer showed a correlation with its combination.4. Endogenous IAA content in superior spikelets of the combinations increased rapidly soon after pollination. While as the IAA content in inferior spikelets was stay still for a period of 7 days from pollination. IAA content in inferior spikelets was much less than the superior spikelets. These phenomena were also observed in their restorers, but as compareto their combinations, the scope of IAA fluctuation was reduced. There was a positivecorrelation of the phenomena between restorer and its combination.5 > Endogenous IAA could be a signaling substance for triggering the grain filling.First, Resulting from isotopes experiments, 3H-IAA accumulation in spikelets was always 3-6 hours prior to H-Glucose accumulation.Second, IAA transport inhibitor-TIBA inhibited the accumulation of 3H-IAA in spikelets; IAA bio-synthesis inhibitor-PCIB inhibited the accumulation of 3H-IAA in spikelets through the inhibiting of 3H-Try transportation; The two inhibitors could also reduce the 3H-Glucose accumulation in spikelets by decreasing endogenous IAA level.Third, Exogenous IAA application on young panicle could be a assisting effects of carbohydrate accumulation in spikelets. The application of high concentration IAA to the young panicle (before anthesis) could improve the seed setting rate of inferior spikelets, and more or less decrease the seed setting rate of the superior spikelets. The main reason of the above phenomena could be a reduced difference of endogenous IAA level in spikelets by exogenous IAA application, and then the apical-grain superiority between superior spikelets and the inferior spikelets was weakened.Therefore, it is considered in this dissertation that endogenous IAA is a signaling substance in triggering the grain filling. There is a positive correlation between IAA emerging time & intensity and the starting & intensity of the grain filling in spikelets. The application of exogenous IAA could improve seed setting rate by weakening the apical-grain superiority. It will be a new stream to the photo-hormone physiology, and will have some practical meaning in improvement of the seed-setting rate by m更多还原