中文摘要：

为了探讨田间植株自遮阴对高粱冠层器官性状及籽粒灌浆的影响,通过排除根系竞争研究了高粱茎叶及果穗籽粒对栽培密度的响应。结果表明,栽培密度升高后,高粱植株的单叶面积、比叶质量（鲜质量）、茎秆节间的直径与干质量、穗柄的直径与干质量等均下降,但茎秆的节间长度与节间数及穗柄长度增加;高粱籽粒干质量随栽培密度的升高而下降,栽培密度对粒质量影响最大的时期是高粱生长的第100天前后;随着叶位与节位的升高,高粱的单叶面积与比叶质量以及茎秆的节间性状等在各密度群体内的变化趋势类似。因此,在排除地下根系间的竞争后,增加种植密度同样会抑制田间高粱冠层器官的生长,并进而影响果穗产量。

英文摘要：

To study the effects of self-shading on canopy organ traits and grain-filling in field-grown sorghum（Sorghum bicolor）under different planting densities, in the absence of root competition, the effects of planting density on stem, leaf and ear were investigated. The results showed that planting density resulted in a distinct decline in single leaf area, specific leaf quality（fresh quality）,and diameter and dry quality of stem internode and spike-stem, whereas, the number and length of stem internode and the spike-stem length exhibited an opposite trend. The grain quality decreased with increased planting density, and the most crucial stage affecting grain quality was rapid filling stage（about the 100th day after sorghum planting）. With increase leaf position of sorghum, single leaf area,specific leaf quality and stem internode traits had similar variation tendencies in three planting densities. Accordingly, the canopy organ and yield of sorghum can be also influenced by planting density in the absence of mineral deficiency.