大豆长花序短果枝株型性状的利用研究 Ⅴ.不同施肥水平和种植密度下长花序短果枝大豆沈农6号的光合性能分析

Utilization of Soybean Germplasm with Plant-type of Long Floral Axis and Short Pod-branch Ⅴ.Studies on Leaf Photosynthetic Traits of Soybean Shennong6with Long Floral Axis and Short Pod-branch Under Different Fertilizer Levels and Seeding Rates

在不同施肥水平和种植密度条件下研究了长花序短果枝株型品种沈农6号叶片的光合性能,结果表明,在同一施肥水平条件下随种植密度的增加叶面积指数最大值呈现递增趋势,但叶面积指数最大值持续时间逐渐缩短。施肥量适中或较低时的叶面积指数在生育后期下降缓慢,而施肥量高时叶面积指数在达到峰值后便急速下降。同一品种鼓粒中期长花序叶、短果枝叶及其它叶片间叶绿素含量差别不大,并且它们受施肥水平和种植密度的影响也比较小。长花序叶的光合速率大于短果枝叶以及短果枝的同节位主茎叶,多数处理组合的短果枝叶的光合速率高于其同节位主茎叶。气孔导度高,细胞间隙CO2 浓度低,光合速率就较大。短果枝叶的光合速率与单株产量相关(r =0 .6 9 )达到显著水平,而长花序叶(r =0 .4 0 )和短果枝同节位主茎叶(r=0 .11)

Leaf photosynthetic traits of soybean Shennong6with long floral axis and short pod-branch were studied under different fertilizer levels and seeding rates in2002.The results were as follows:At the same fertilizer level,the values of maximum LAI increased as the increment of seeding rate,but the duration of maximum LAI was decreased.High fertilizer level would result in the fast defoliation of population after flowering.There were no significant differences of chlorophyll content among the leaves on the nodes of long floral axis,short pod branch and main stem.However the photosynthesis rate of the leaf on the node of long floral axis was higher than those on the nodes of short pod branch and main stem,the photosynthesis rate of leaf on short pod branch was higher than that of leaf at the same node of main stem.The photosynthesis rate of leaf on short pod branch had a significant relationship with the grain weight per plant.Also Leaf Dura-tion Days of short pod branch leaf had a significant difference under different seeding rates.but there was no significant difference under different fertilizer levels,which meant that the effect of seeding rate on Leaf Duration Days of short pod branch leaf was bigger than that of fertilizer level.