茭白碳水化合物积累与分配特性研究

Studies on Accumulation and Allocation of Carbohydrate in Zizania latifolia

以茭白品种‘蒋墅茭’和‘葑红早’为试材的研究表明 :在肉质茎膨大之前 ,植株茎蘖各部位的总糖、还原糖、淀粉积累量持续上升 ,短缩茎中积累量最高 ;肉质茎膨大开始时 ,各部位碳水化合物积累量下降 ,以短缩茎的下降量最大 ,认为膨大前叶片的光合产物在短缩茎和叶片中积累以短缩茎为主 ,植株积累的碳水化合物主要以淀粉形式存在。孕茭前 1 4 C同化物在短缩茎的分配率较大 ,上位叶片、叶鞘也有较多积累 ,肉质茎膨大过程中 ,大量的1 4 C同化物在肉质茎中积累。饲喂叶片光合产物除供应自身茎蘖外 ,还向植株其它各部位输送。

The changes of carbohydrate accumulation in leaves and stems of the Zizania latifolia were studied on two typical varieties at their differ ent grow th and development stages.The allocation of photosynthesis assimilates in differ ent organs was also determined by using 14 C-labeling technique.The re sults showed that,before the Zizania gall expanding,the accumulation of tota l sugar,reducing sugar and starch increased continuously and the greatest amount of carbon assimilates were observed to be accumulated in the culm,as compared w ith that in other organs.When Zizania gall began to expand,the carbohydrate in other organs stopped accumul ation.Most carbohydrates stored in culm were remobilized.The culm serves as sto red organs for remobilized assimilates to the growth of Zizania gall.Starch is t he main form for stored carbohydrate,and most of 14 C assimilates was p re-fixed in culm before pregnant.The accumulated carbohydrate in the up leaf a nd sheath of plant was higher than that of its low leaf and sheath.During the p eriod of Zizania gall expanding,most of prefixed- 14 C was remobili zed into gall.The labeled assimilates fixed by leaves supplied not only for its straws but also for the other parts of the plant.