【作者】 杨连新；

【导师】 王余龙；

【作者基本信息】 扬州大学 ， 作物栽培与耕作学， 2002， 博士

【摘要】 在大田、盆栽、群体水培等条件下，以籼稻、粳稻和杂交稻等不同类型品种为供试材料，在谷壳形成期设计多种处理改变稻体内氮、碳水平，研究其对谷壳生长和发育的影响，以及在谷粒充实期设计多种处理改变灌浆物质供应水平，研究其对谷粒充实的影响，企图明确提高水稻粒重的机理、途径和方法。主要结果如下： 1．在不同栽培和环境条件下，同一水稻品种的千粒重有较大差异。其中，扬稻6号千粒重的极差为6.69g，最大千粒重是最小千粒重的1.28倍；日本晴千粒重的极差为7.52g，最大千粒重是最小千粒重的1.38倍；武运粳8号千粒重的极差为3.79g，最大千粒重是最小千粒重的1.15倍；汕优63千粒重的极差为5.85g，最大千粒重是最小千粒重的1.25倍。从不同比重等级籽粒的千粒重来看，盐粳2号千粒重的极差为4.34g，最大千粒重是最小千粒重的1.22倍；扬稻4号千粒重的极差为8.89g，最大千粒重是最小千粒重的1.41倍；汕优63千粒重的极差为7.40g，最大千粒重是最小千粒重的1.31倍；02428／明恢63千粒重的极差为10.76g，最大千粒重是最小千粒重的1.54倍。 2．适当降低移栽至抽穗期的供氮浓度或适量施用分蘖肥，能明显增大谷壳面积，显著提高千粒重；增加移栽至抽穗期的供氮浓度或过多施用穗肥，使谷壳面积明显减少，千粒重显著下降；适量施用粒肥能提高千粒重；抽穗前15d至抽穗期进行遮光、缺水或抽穗前15d剪根处理均使谷壳面积减小和谷粒充实度降低，千粒重显著下降；增加土壤通透性，促进根系生长，能明显增加谷壳面积和谷粒充实度，千粒重显著提高；适当降低土壤容重能明显增加日本晴谷壳面积和谷粒充实度，显著提高千粒重，而土壤容重过高将使谷壳面积减少、谷粒充实度降低，千粒重明显下降；扬稻6号的千粒重以土壤容重1.45g·cm^-3处理为最高，土壤容重过高过低均使谷壳面积减少、谷粒充实度降低，千粒重显著下降。 3．增加谷壳的长度和宽度能提高灌浆前期的灌浆速度，促进糙米的生长，增大糙米体积，使粒重显著提高；增加单位谷壳面积谷壳重能显著提高籽粒的充实程度，使粒重显著提高。在不同栽培和环境条件下，谷壳大小是造成处理间粒重差异的主要原因，不同类型品种表现一致；在籽粒不同比重条件下，谷粒充实度高低是造成不同比重等级谷粒千粒重差异的主要原因，不同类型品种表现一致。 4．扬稻6号谷壳长度、宽度的生长均呈“S”型曲线，可用Richards方程拟合。一般抽穗前10～14d是谷壳伸长、增宽最快的时期，谷壳增宽较谷壳伸长稍为滞扬州大学博士学位论文后;增加谷壳快增期生长速度（VZ）和最大生长速度（Vm）能显著增加谷壳的长度和宽度;通过栽培条件适当降低谷壳形成期植株的含氮率、提高谷壳形成期植株的可溶性糖和淀粉含t，均能显著增加谷壳的长度和宽度。 5.促进谷壳的物质积累，增加单位谷壳面积的谷壳重能显著提高谷粒的充实程度，不同类型水稻品种表现一致。抽穗后不同花势谷壳增重过程有显著差异，强势花谷壳增重快，多于抽穗后15d左右达到最大值:弱势花谷壳增重速度明显慢于强势花，且历时长，在抽穗后35d左右才能达到或接近最大值;结实期强、弱势花谷壳增重幅度为51.16¹16.37%，.弱势花增幅明显大于强势花。 6.改变栽培条件和耕作措施等，改善土壤通透性，在谷壳形成期适当降低植株含氮率，增加植株可溶性糖和淀粉含量，调节植株碳氮比率，促进根系生长，能显著增大谷壳面积和促进谷壳的发育;在谷粒充实期提高根系活性，防止叶面积迅速下降，提高净同化率，增加灌浆物质量和谷壳的物质积累量，可显著提高谷粒的充实程度。更多还原

【Abstract】 Field and pot and dydroponical experiments were carried out in Yangzhou university in 1999 ~ 2002 with different varieties as materials including typical indica, japonica and hybrid indica. With a large numbers of treatments for changing nutritious level of plant during hull formation stage, effects of that on hull growth and development were studied. And with a large numbers of treatments for changing levels of available grain filling substances in the filling stage, effects of that on grain plumpness were studied. These experiments were supposed to illuminate the mechanism and ways of improving grain weight in rice. Main results obtained were as follows:1. 1000-grain weight of every varieties varied significantly under different cultural and environmental conditions. The 1000-grain weight ranged 6.69g under different cultural and environmental conditions in Yangdao 6, 7.52g in Nipponbare, 3.79g in Wuyunging 8, 5.85g in Shanyou 63. The ratio of the maximal grain weight to the minimum grain weight was 1.28 in Yangdao 6, 1.38 in Nipponbare, 1.15 in Wuyunging 8, 1.25 in Shanyou 63; 1000-grain weight of the different specific gravities ranged 4.34g in Yanging 2, 8.89g in Yangdao 4, 7.40g in Shanyou 63, 10.76g in 02428/Minghui 63. The ratio of the maximal grain weight to the minimum grain weight of the different specific gravities was 1.22 in Yanging 2, 1.41 in Yangdao 4, 1.31 in Shanyou 63 and 1.54 in 02428/Minghui 63.2. Reducing N application concentration from transplanting to heading properly or employing feasible amounts of tiller promoting fertilizer would result in obvious increment of hull area and grain weight. While raising N application concentration fromtransplanting to heading or employing excessive spike fertilizer would result in obvious decrement of hull area and grain weight. Employing feasible amount of top dressing at heading would be beneficial to grain weight increment. Compared with CK, Shading and water stress treatments during hull formation stage or root-cutting treatment on the 15th days before heading would result in obvious decrement of hull area, grain plumpness and grain weight. Sand-adding treatment for promoting root growth would redound to hull area, grain plumpness and grain weight significantly. Effects of soil bulk density on hull area and grain plumpness and grain weight were subjected to the varieties. Optimum soil bulk density was 1.30g cm-3 for Nipponbare, 1.45g cm-3 for Yangdao 6.3. Increasing hull length and hull width could raising grain filling rate at early stage, promote growth of brown rice, and that would result in obvious increment of brown rice volume and grain weight. Increasing hull weight per unit hull area would raise grain plumpness and grain weight significantly. The variation of grain weight under different cultural and environmental treatments was essentially determined by the hull size, and that of grain weight among different specific gravities was essentially determined by grain plumpness, that were found to be consistent in the four varieties.4. The dynamic changes of hull length and width could be described with the Richards equation in Yangdao 6. In general, the maximum rate of hull growth were reached on the 10th~14th days before heading. The increment of hull width was a little slower than that of hull length. Ultimate length and width of hull were mainly subjected to hull growth rate during the main growth period(V2) and maximum hull growth rate(Vm). Reducing nitrogen content of plant properly and increasing content of soluble and insoluble carbohydrates of the plant during hull formation stage by feasible cultural conditions could increase hull length and hull width significantly.5. Raising dry matter accumulation and hull weight per unit hull area would result in the increment of grain plumpness, that was found to be consistent in the four varieties. Patterns of hull weight increment of strong and weak potential spikelets were quite different. For the hull of strong potential spikelets(SPSs), its weight increased very qu更多还原