THE RELATIONSHIP OF SOURCE AND SINK IN SEMI-DETERMINATE SOYBEAN

Li Xinmin Xu Zhongren Du Weiguang Hu Lichen (Soybean Res. Institute, Heilongjiang Academy Agricultural Sciences)

Leaf - pod relation; Physiological compensation; Source - sink unit; Semi -determinate soybean

The relationship of source and sink of different plant sections (upper, middle, bottom and branches) was studied by using the methods of defoliation. The results indicated that there existed two main source - sink units in semi - determinate soybean during reproductive stage, one was upper and middle sections of main stem, the other was section bottom of main stem and branches. When removing leaves of different plant section, we found that all sorts of physiological compensation mainly appeared within the source-sink unit mentioned above. Moreover, the intensity of compensation changed from low to high with plant development. It seemed that when the Iorigi-nal balance of source-sink relation was brokem, mew balance shoud be established by its internal adjustment. The ratio of source anf sink influenced not only photosynthetic rate but also transportion and partition of the photosynthate.