不同种植密度对小麦籽粒灌浆特性及产量的影响

Effects of Planting Density on Grain Filling Characteristics and Grain Yield of Winter Wheat

[目的]研究不同种植密度对冬小麦籽粒灌浆特性及产量的影响，以期为河西灌区冬小麦高产栽培制定合理的密植范围。[方法]设计了225万（T1）、300万（T2）、375万（T3）、450万（T4）、525万（T5）、600万（T6）、675万（T7）、750万（T8）、825万（T9）、900万（T10）、975万（T11）、1050万（T12）基本苗／hm^2共12个密度处理，分别运用Richards模型、一元二次方程模拟了冬小麦籽粒干物质增长过程及籽粒灌浆速率随花后时间的变化情况，并对所建立的Richards模型进行推导得到基本的灌浆参数，通过SPSS、DPS软件对籽粒灌浆参数与千粒重进行相关、逐步回归及以及通径分析。[结果]不同密度处理间千粒重、单位面积穗数、穗粒数、单株穗数、单位面积籽粒产量均存在显著差异；不同密度处理冬小麦的籽粒灌浆均符合慢-快-慢的“S”型生长特性，用Richards模型能很好地模拟冬小麦籽粒增重过程，用一元二次抛物线方程能较好地模拟冬小麦灌浆速率随花后时间变化过程；不同密度处理间平均灌浆速率、最大灌浆速率有较大差异，最大差异率分别为33．98％、22．61％，1_7的平均灌浆速率1．26mg／（grain·d）及最大灌浆速率2．44mg/（grain·d）均最大，T12的平均灌浆速率0．94mg／（grain·d）及最大灌浆速率1．99mg／（grain·d）均最小；平均灌浆速率、最大灌浆速率、灌浆活跃期、灌浆快增期与千粒重显著或极显著正相关，相关系数分别为0．628％、0．630^＊、0．849^＊＊、0．739^＊＊；通径分析表明，灌浆活跃期对千粒重的贡献最大。[结论]灌浆活跃期对千粒重的贡献最大，河西绿洲灌区冬小麦的适宜密度范围为675万～750万基本苗／hm^2。

[ Objective ] The research aimed to research the characteristics of grain filling and grain yield of winter wheat under different planting density in order to determine the reasonable winter wheat planting density. [ Method] Twelve density treatments were designed, which were 225×104（T1）, 300×104（T2）, 375×104（T3）,450×104（T4）, 525×104（T5）, 600×104（T6）,675×104（T7）, 750×104（T8）, 825 × 104（T9）, 900 × 104（T10）, 975 × 104（T11 ） and 1 050 × 104（T12） basic plants/hm^2. Grain dry matter growing process and grain filling rate could be described by Richards Model and Monodic Quadratic Equation, and the grain filling parameters could be calculated from Richards model fomula. Relation analysis, stepwise regression analysis and path analysis were made by DPS, SPSS software. [ Result ] Richards Model and Monodic Quadratic Equation could properly describe grain dry matter growing process and the change process of grain filling rate with days after anthesis. There was big difference in average grain filling rate, maximum grain filling rate under different planting density. Average grain filling ratel. 26 nag/（ grain · d） and maximum grain filling rate 2.44 mg/（ grain · d） of T7 were the quickest, and the average grain filling rate 0.94 mg/（ grain · d） and maximum grain filling rate 1.99 mg/（ grain · d） of T12 were the slowest, and the maximum difference percentage of the average grain filling rate and maximum grain filling rate among different density were 33.98% , 22.61%. There was significant correlation between average grain filling rate, maximum grain filling rate, grain filling active duration, rapid increasing stage and thousand grain weight（ TWG）, and the correlation coefficients were 0. 628 ^＊ , 0. 630 ^＊ , 0. 849^ ＊ ＊ , 0. 739^ ＊ ＊. Active grain filling duration con- tributed mostly to TGW. [ Conclusion] Active grain filling duration contributed mostly to TGW. 675 × 10^4 - 750 × 10^4 basic plants/hm^2 was the most optimum planting density in Hexi oasis district.