荸荠生育过程中叶状茎内碳水化合物代谢的变化

(1)荸荠生育过程中,叶状茎中转化酶活性有所下降,淀粉酶活性则增加。(2)叶状茎照光后,先迅速合成可溶性糖类,而后才合成淀粉,亦即淀粉的快速合成比可溶性糖的快速合成时间稍迟。(3)叶状茎中碳水化合物含量的日变化在晴天和阴天基本相同,但变化幅度的大小受气候条件的影响。晴天糖类的日相对变化幅度较大,淀粉的日相对变化较小;阴天则相反。(4)温度和无机磷对叶状茎蔗糖合成能力有明显的影响。温度在25—30℃时,蔗糖合成能力较强。低浓度(0.01—0.05M)KH_2PO_4会促进蔗糖的合成,较高浓度(超过0.05M)时会抑制蔗糖的合成。

CHANGES OF CARBOHYDRATE METABOLISM IN LEAFY STEM DURING GROWTH AND DEVELOPMENT OF CHINESE WATER-CHESTNUT

The present study is intended to find out the change of carbohydrate metabolism in leafy stem of chinese water--chestnut (Eleocharis tuberosa Shulf).The results shows that the activity of invertase decreased and that of amylaseincreased through the grouth Period. Under light condition, starch was synthe-sized in the leafy stem. But the time of synthesis was a little later than thatof sulable sugars. Diurnal change of Carbohydrate Content in the leafy stem hadthe same tendency in either fine day or cloudy day, but the extent of thevariation was different. Sucrose biosynthesis in the leafy stem were affected by temperature andthe concentration of inorganic phosphate. The capacity of sucrose biosynthesiswas higher at higher temperature, and was promoted by low concentration ofinorganic phosphate and inhibited by higher concentration.