中文摘要：

【目的】揭示小麦株型指标变化规律及播种密度对株型指标的影响。【方法】基于不同播种密度和不同株型品种的小麦田间试验,通过连续观测主要生育时期小麦主茎叶型和茎型指标,分析并模拟分层叶面积、叶向值、株高构成指数等株型指标的动态变化规律及播种密度对其的影响。【结果】不同株型品种分层叶面积指数（LAI）均表现为中部〉上部〉下部的分布特征,并随生育期的推进逐渐向中上部集中,且冠层中上部总是高密度群体LAI较大。所有品种高低密度间株高构成指数（穗下节与倒二节间长度之和与株高的比值,IL）均表现出显著差异,不同株型品种株高构成指数（n节间长与n节间加n-1节间长度之和的比值,In）表现为从下至上先减小后增大的趋势,且上部节间受密度影响较大。较为紧凑的矮抗58叶向值在不同密度下表现平稳,随生育进程略微表现为增大—减小—趋缓的趋势;较为披散的扬麦12号中高密度下随生育进程均表现为平缓—减小—平缓的趋势;扬麦16号则表现为平缓—减小—略微增大的趋势。在分析株型指标变化趋势和课题组已有形态模型的基础上,通过冠层切割和叶面积积分的方法模拟了叶面积指数的分层动态变化,利用组合的形态参数模拟了株高构成指数和叶向值的动态变化,并通过对形态指标的归类分析,构建了综合性株型构成指数,综合体现了叶型和茎型的动态变化。利用独立试验资料对分层叶面积指数、株高构成指数和叶向值的动态变化模型进行了检验,其平均RRMSE分别为17.44%、7.64%和10.66%。【结论】经检验,该模型对上述小麦株型指标具有较好的预测性。

英文摘要：

【Objective】This study was designed to explore the dynamic changing characteristics of wheat（Triticum aestivum L.） plant type index and the effects of planting density on plant type index.【Method】Based on the field experiments with three cultivars（Aikang 58 with erect leaf,Yangmai 12 and Yangmai 16 with flat leaf） and three planting densities in wheat,the time-course measurements were carried out on the indices of leaf type and stem type at main growing stages of wheat,and then the dynamic changing patterns of plant type indices and the effects of planting density on the dynamics of plant type indices in wheat were analyzed and simulated.【Result】The results indicated that the layer LAI of different plant-type cultivars had a trend of ＂middle layer upper layer lower layer＂,and the layer LAI was gradually concentrated in the middle or upper layer with the growing progress.In addition,the larger LAI of the middle or upper layer was observed on high population density.The significant differences of plant height component index（the ratio of the length of rachis and penultimate internodes to plant height,IL） between high and low population densities were observed.The plant height component index（the ratio of the length of n internode to the length of n internode adding（n-1） internode,In） of different plant-type cultivars were all decreased first and increased later from lower to higher leaf positions.In addition,the remarkable effect of planting density was observed on In of upper internode.As for Aikang 58,a relatively constant LOV with a slight ＂up-down-easing down＂ trend was observed.As for Yangmai 12,the change pattern of LOV was in ＂gentle-decrease-gentle＂ trend.As for Yangmai 16,a trend of ＂gentle-decrease-increased slightly＂ was showed.Based on the analysis of plant type index dynamics and the existing morphological model,the dynamics of layer LAI was simulated by using the methods of canopy cutting and leaf area integration,and the dynamics of the plant height comp