杜仲形成层活动周期中多糖贮量和淀粉酶同工酶的变化

杜仲(Eucommia ulmoides)枝条中的多糖颗粒经Ⅰ-KI溶液染色不显蓝黑色反应,偏光显微镜检查也不显示各向异性。髓、木质部、木射线和皮层薄壁细胞内多糖贮量的变化和形成层的活动周期有关:从5月下旬至12月中旬,逐步积累:从12月下旬至翌年4月中旬则逐步消失。韧皮部薄壁细胞中的多糖颗粒很少,而且没有季节性变化。淀粉酶同工酶酶谱在不同组织中不同,并随形成层的活动状态而变化,但与多糖颗粒的积累和消失无相关关系。

Changes of Polysaccharide Storage and Amylase Isozyme Activity in Relation to the Annual Cycle of Cambium Activity in Eucommia ulmoides Shoots

The polysaccharide granules in tissues of Eucommia ulmoides stained noblue-black with I-KI solution and showed no anisotropy under polarized micro-scope.The seasonal changes of polysaccharide granules in the pith,xylem and cor-tex parenchyma of the shoots were mere related to the annual cycle of cambial activ-ity.Polysaccharide granules accumulated from the end of May to mid-December,and degraded gradually until mid-April of the following year. A few polysaccharidegranules existed in the phloem parenchyma and their variation was less obviousthan that in xylem and cortex.Zymogramphy of amylase isozymes was differentamong tissues.Albeit the enzyme activities changed during the annual cycle of cam-bial activity,but showed no interrelation with the accumulation and degradation ofpolysaccharide granules.