播量与追氮量对BNS型杂交小麦灌浆期冠层结构及产量的影响

为了明确BNS型杂交小麦的高产形成机理，以3个不同类型的BNS型杂交小麦为材料，采用正交试验设计，研究了不同播量与追氮量下BNS型杂交小麦生育后期的冠层结构及产量性状变化。结果表明，与常规品种相似，BNS型杂交小麦的冠层性状随生育期的推进而呈规律性的变化。花后13 d时，冠层上部叶片叶绿素含量逐渐上升，至花后20 d时达最大值，呈现先升高后降低的趋势；此时中部叶片叶绿素含量最高，而下部叶片急剧衰亡；冠层中上部叶面积指数因品种不同而有一定差异，叶片功能期越长产量越高；不同类型小麦品种冠层透光率亦有所不同。冠层中上部透光率在抽穗期叶面积指数较大时较高，在灌浆中期随叶面积指数的下降而降低，灌浆后期透光率增大。本研究结果表明，不同小麦品种的冠层结构及产量因素受播量与追氮量的影响不同，杂交小麦生育后期受播量与追氮量的影响较大。良种良法配套是实现杂交小麦高产的技术保证。

Effects of Planting Density and Nitrogen Fertilizer Rate on the Canopy Structure at Grain Filling Stage and Yield of BNS Hybrid Wheat

The canopy structure and yield traits of BNS hybrid wheat were investigated in treatments with different sowing quantity and nitrogen fertilizer rate. The experiment was designed using orthogonal experiment design and 3 different kinds of wheat hybrid varieties were used,in order to probe into the high-yield formation. The results showed that canopy traits of BNS hybrid wheat changed with growth period,similar to conventional varieties. Chlorophyll content in upper leaves increased gradually at 13 d after anthesis,reached the maximum value at 20 d after flowering with trend of increasing first and then decreasing. The chlorophyll content of middle leaves reached the highest at this time,but the lower leaves declined sharply. The LAI was different for different hybrid wheat varieties,the longer the functional period of leaves was,and the higher the yield was. The canopy light transmittance of different kind of hybrid wheat was difference and the higher transmittance was achieved when the LAI was larger in upper parts,but the canopy light transmittance decreased when the LAI was smaller at middle filling stage,and it increased at late grain-filling stage. There was significant difference in yield components of different BNS hybrid wheat,increasing seeding rate appropriately could contribute to gain larger population and achieve higher yield. The results proved that planting density and nitrogen fertilizer rate influenced the canopy structure and yield traits of different wheat varieties,and for hybrid wheat largely at late growth stage,so the compatible technique with good varieties and good technical measures were the key to achieve higher yield.