杜仲形成层的活动式样

杜仲形成层在３月下旬芽开始绽开时恢复活动，同时产生木质部和韧皮部。７月底形成层细胞停止分裂，同时停止产生韧皮部，８月中旬停止产生木质部。过氧化物酶、酶酶和淀粉酶的同工酶酶谱及活性，以及多糖颗粒的贮量都随形成层活动周期的变化而变化。但多糖颗粒不是淀粉粒，不过它们的变化说明，７月下旬进入第一被动休眠期，１１月中旬进入生理休眠期，１１月底进入第二被动休眠期。

Pattern in Cambial Activity in Eucommia ulmoides

In Eucommia ulmoides , the cambium reactivated at the last ten days of March when buds were sprouting and produced secondary xylem and phloem. And the cambium cells ceased to divide and to differentiate into pholem at the end of July, but continued to differentiate into xylem until mid-August. The variations of polysaccharide content and zymogram and activity of peroxidase, esterase and amylase isozyme were related to the periodicity of cambial activity. But the polysaccharide granues were not starch granues. However, it showed that cambum entered first quiescence at the end of July, and the rest at mid-November, and the second quiescence at the end of November.