【作者】 李运祥；

【导师】 王忠；

【作者基本信息】 扬州大学 ， 植物学， 2004， 硕士

【摘要】 通过盆栽试验对扬稻六号和粳稻941两个水稻品种进行施氮时期和施氮量的处理，研究了不同施氮处理对水稻植株生长、颖果发育、胚乳细胞结构和稻米品质的影响。其主要结果如下： (1)提高分蘖期施氮量能增加水稻植株的鲜重和干重、分蘖数和株高；提高孕穗期施氮量能增加灌浆期水稻剑叶叶绿素含量和可溶性蛋白含量，延缓植株衰老，延长籽粒灌浆充实。 (2)增加穗肥施氮量能增加颖果鲜重和干重，提高颖果和颖壳叶绿素含量。增加穗肥施氮量能显著降低灌浆初期颖果中可溶性糖含量和颖果中淀粉含量。 (3)颖果中直链淀粉和支链淀粉含量随粒重的增加而上升，二者积累具有同步性；增加穗肥施氮量能显著降低颖果中直链淀粉含量，并使颖果中直链／总淀粉的比例降低。 (4)颖果中ADPG焦磷酸化酶、SSS酶、GBSS酶和SBE酶活性变化趋势均呈单峰状态。即在灌浆前期随着花后天数的增加而升高，到花后10～15d左右酶活性达到峰值，以后随着花后天数的增加而逐渐降低，籽粒增加施氮量特别是增加穗肥施氮量可以提高籽粒中ADPG焦磷酸化酶、SSS酶和SBE酶的活性，降低籽粒灌浆前期GBSS酶的活性。 (5)颖果中蛋白质百分含量随颖果的充实而逐渐下降，但单个籽粒中蛋白质含量却随粒重增加而增加。增加穗肥施氮量能显著提高颖果中蛋白质量。增加穗肥旌氮量对颖果中蛋白体、淀粉体发育和糊粉层的形成均有显著的影响。增加穗肥施氮量可以延长籽粒灌浆时间，使籽粒中淀粉体充实良好。 (6)增加穗肥施氮量能提高籽粒糙米率、精米率、整精米率、蛋白质含量，降低稻米垩白率和直链淀粉含量，对稻米品质有改善作用。更多还原

【Abstract】 Pot experiments were conducted to study the effects of various nitrogen treatments on rice seedlings’ growth, caryopses development, endosperm microstructure and ripening grains qualities by two commonly grown rice cultivars. The main results are the following:(1) The increased nitrogen fertilizer used at the tillering stage can significantly enhance the fresh and dry weights, tillering numbers and heights of rice seedlings. The same is true for the chlorophyll and soluble protein content in the rice flag leaf when topdressing was used at the heading stage, it can retard grain filling process and senescence in the later stage of rice.(2) The topdressing ratio of nitrogen fertilizer at the heading stage is positively correlated to the chlorophyll content in caryopses. The nitrogen fertilizer treatments had significantly effect on the fresh and dry weights of the caryopses. Increased of application rate of ear manture can decrease significantly soluble sugar at the initial stages of the rice grain fillling and starch content in caryopses.(3) The amylose and amlyospetcin content in the caryopses increase gradually with the increased weight of grains, and the accumulation of them were simultaneity at the same time. Topdressing ratio of nitrogen fertilizer at the heading stage is negatively correlated with the amylose content in caryopses, and topdressing ratio of nitrogen fertilizer at the heading stage affected the ratio of amylose to total starch in caryopses development.(4) The changes of ADPG-PPase(AGP), soluble starch synthase(SSS), granule-bound starch synthase (GBSS) and starch branching enzyme (SBE) activities in the caryopses is a single peak curve. That is, the enzyme activities increase at the initial stage of grain filling with day after flowering, reach their peak at 10~15d after flowering, and then activities of them decreased with days increase. Increased topdressing ratio of nitrogenfertilizer at the heading stage can enhance AGP, SSS and SBE enzyme activities in grains, and decrease GBSS enzyme activity in early filling.(5) The protein percent content in caryopses decreases gradually during the rice grain filling, but the protein content in each rice grain increases with the grain weight increasing. Increased of application rates of ear manture is markedly positively correlated with the protein content in caryopses. Increased topdressing of nitrogen fertilizer at the heading stage had significant effect on the development of protein bodies and amyloplasts, and the formation of aleurone layer in caryopses. It can retard grain filling process and make amyloplasts developed enough.(6) Increased topdressing of nitrogen fertilizer at the heading stage raised the ratios of brown, fine and integrated fine rice grains and increased protein content compared with the control group, while decreased the degree of opaqueness and amylose content. That is, the nitrogen fertilizer can markedly improve the rice grain qualities.更多还原