Regulation of Dry Matter Production Process in Response to Changes in Photosynthetic Source-Sink Balance by Environ-mental factor

大豆(Glyine max Merr.)CV。Tsurunoko)植株是在人工气候室中放置在充足光照条件下的盆栽中种植的。植物的光合库容量通过去除花蕾和阻止结荚的形成而受到限制，而结荚是生殖生长期的主要库器(库限植物)。(1)库限植株的叶面积与叶重、叶重与非光合器官的比值(源器官与库器官的比值)均大于对照植株。(2)摘除花芽后，叶片的光合作用活性随蔗糖含量的增加而逐渐降低。库限植株的光合作用活性与蔗糖含量呈负相关。(3)在库限植物中，RuBPcase活性随着光合作用活性的降低而显著降低。加入CO_2和Mg~(2+)、Gt~(2+)能完全恢复酶活性。(4)限制库型植物叶片中RuBP的含量随着光合作用活性的降低而显著降低，通过去除花蕾制备的库限型植物所获得的结果与源库模型植物在改变源/库平衡时观察到的结果一致(Sawada等，1986,1987ab，1989,1990,1992)。

Soybean (Glycine max Merr. cv. Tsurunoko) plants were grown in pots placed under a sufficient light condition in a phytotron. Photosynthetic sink capacity in the plants was limited by removing flower buds and stopping formation of pods which were main sink organs at reproductive stage (sink-limited plants). (1) Ratios of leaf area to leaf weight and of leaf weight to non-photosynthetic organs (ratios of source organs to sink organs) of the sink-limited plants were larger than those of the control plants. (2) By removing flower buds, photosynthetic activity successively lowered with increasing sucrose content in leaves. Negative correlations existed between photosynthetic activity and sucrose content in the sink limited plants. (3) In the sink-limited plants, the activity of RuBPcase significantly lowered according to lowering of photosynthetic activity. This lowered activity was perfectly recovered with addition of CO_2 and Mg^<2+>. (4) The RuBP content in leaves of the sink-limited plants largely decreased with lowering of photosynthetic activity.It is concluded that the results obtained from the sink-limited plants prepared by removing flower buds are consistent with the those which were observed in the source-sink model plants when the source/sink balance was altered (sawada et al., 1986, 1987ab, 1989, 1990, 1992).