大豆群体冠层叶粒与光照垂直分布规律的初步分析

Preliminary Analysis on Vertical Distribution Of Leaves Grain And Light Of Colony Canopy Of Soybean

本研究对亚有限和无限类型品种（品系）在不同密度条件下的ＬＡＩ、粒重、光照垂直分布进行了分析。亚有限类型在结共、鼓粒期ＬＡＩ以冠层上部节位为主、中层次之；无限类型以中层节位为主、下层次之；开花期相对光强以冠层上部最高、下部最低；亚有限类型上部相对光强低于无限类型；亚有限和无限类型粒重分布主要集中于中上层，其中亚有限类上层比例最高、无限类型中层比例最高。密度对叶、粒、光分布影响显著；随密度增加，在开花至鼓粒期，上层节位ＬＡＩ呈现增加趋势，下层呈现减少趋势；粒重亦为上层递增、下层递减；开花期相对光强分布，随密度增加，上、中、下层均呈现递减之势。根据不同品种（品系）类型叶、粒无分布特点，确定合理的栽培措施，充分发挥产量主导层次生产潜能，是进一步提高大豆子粒产量的有效途径。

The distribution of LAI, grain weight and relative intensity of illumination under different planting density has been studied for semi-determinate and indeterminate varieties (lines). The distribution of LAI for semi-determinate varieties (lines) during podding and filling stage is largely at the part of top nodes of the plant and secondly at the part of middle nodes and for indeterminate ones mainly at the part of middle nodes and secondly at the part of top nodes. The distribution of relative intensity of illumination during flowering stage is the highest at the part of top canopy and lowest at the part of top nodes. The distribution of relative intensity of illumination during flowering stage is the highest at the part top canopy and the lowest at the part of bottom canopy. The distribution of relative intensity of illumination at the part of top canopy for semi-determinate varieties (lines) is lower than that of indeterminate ones. For semi-determinate and indeterminate varieties (lines) the rate of grain weight is largely distributed at the part of middle and top nodes while the rate of grain weight is the highest at the part of top for semi-determinate ones and at the part of middle for indeterminate ones. Planting density effects on the distribution of LAI, grain weight and relative intensity of illumination in vertical direction to a large extent. With increasing of planting density, LAI increased at the part of top nodes and decreased at the part of bottom nodes from flowering stage to filling stage while the rate of grain weight increased at the part of top and decreased at the part of bottom. With increasing of planting density, the relative intensity of illumination decreased from top to bottom in the canopy in flowering stage. It is an effective way for promoting the yield significantly to determine suitable management and dig up productive potential of the most efficient vertical portion for soybean in accordance with the characteristic of distribution on the leaf, grain weight and light in vertical direction for different type of varieties(lines).