大豆植株光合性能与干物质及荚粒形成关系的研究

大豆生育期间,群体中的单株干物质日增量、单株光合速率及单株光合面积均呈单峰曲线变化。其中,日增量在开花期以前和鼓粒期以后受光合面积的支配,而在开花期至鼓粒期则主要受光合速率的制约。 群体中的单株各节位间,叶片平均光合速率、平均光合面积、总光合势和总光合量与荚数、粒数及总粒重的高低分布趋势基本一致、均以中上部节位最大,基部和顶部节位最小。各指标间,以总光势和总光合量与籽粒数及总粒重的线性正相关较强,达显著水平。 结果还表明,盆栽植株各节位叶片的光合性能和荚粒形成量,均优于群体中的单株各对应节位叶。

STUDIES ON THE RELATIONSHIP BETWEEN PHOTOSYNTHETIC CAPACITIES AND FORMATIONS OF DRY MATTER AND SEED YIELD IN SOYBEAN PLANTS

The diurnal dry matter increment of single plant changed maily with net photosynthetical rate and leaf area of plant during soybean growth and development stage. There was a positive correlation between dry matter increment and leaf area of single plant in the period before blooming and after filled green bean. But during other growth stages, it correlated with net photosynti-cal rate per plant positively. In the community of soybean, the nodes which located at the positions betweed middle and upper parts of main stem showed dominant positions in vertical distibu-tions of leaf area(LS) , total leaf area duration(LAD) , average value of leaf net photosynthetical rate (LA), total leaf photosynthate (TLA) , number of pods(P), unmber of beans(B) and total bean weight(BW). The results of regression analysis among those varables indicated that the correlation between TLA and B or BW and between LAD and P. B, or BW were high (r=0. 9167 - 0. 9376), but the crrelation between LS and P,B,or BW and between LA and P,B,or BW in lower nodes of main stem were low. Furthmore, pot-culture condition had a some improvement than under field-culture condirion on LA, LS, LAD,TLA,P,B,BW, transpiration and water using efficiency in each corresponding node of main stem. The results also showed that the relationships between photosynthetical capability and bean yield were so complex that it is imposible to explain directly the formation of bean yield by means of net phototsynthetical rate per unit laef area, leaf index or leaf area durationindividually. Therefore we suggested that photosynthetical capicity, community structure and ecological conditions must be considered together in the period of plant growth and development.