secondary vascular tissue

The main cause of root tuber expanding is that phellogen produces many layers of phelloderm parenchyma cells and vascular cambium produces a lot of secondary vascular tissue that consists of parenchyma.

但在以后的发育过程中，木栓形成层产生了多层栓内层薄壁细胞，维管形成层则产生了大量高度薄壁组织化的次生维管组织，从而形成了肉质膨大的块根。

With the progressive development of stem, the activity of vascular cambium began. The fascicular cambium differentiated into secondary xylem and secondary phloem, while the interfascicular cambium only differentiated into wide ray of parenchyma tissue.

随着茎的继续发育，维管形成层开始活动，由束中形成层产生次生韧皮部和次生木质部分子；而束间形成层仅产生薄壁细胞组成宽的射线。

It is well known that the developmental inherent rhythm occurs during the development of secondary vascular tissue. Synchronously, the cell ergastic substance shows dynamic changes.

众所周知，树木次生维管组织的发育具有内在的节律性，与此同时维管组织的细胞内含物也会发生动态变化。

Secondary vascular tissue, found only in plants with secondary thickening , develops from the vascular cambium.

次生维管组织由维管形成层发育而来, 仅存在于有次生加厚的植物中.

Therefore, the secondary structure included periderm, pericyclic parenchyma tissue and secondary vascular tissue from the outside to the inside of taproots of Bupleurum chinense DC.

因此，北柴胡根的次生结构从外到内由周皮、中柱鞘薄壁细胞环和次生维管组织组成。

The distribution of cell ergastic substance was closely related to the developmental inherent rhythm of secondary vascular tissue.

杨树维管组织发育过程的内在节律性与细胞内含物的动态变化密切相关。

The results showed that all the cross branch roots of different sizes consisted of periderm, secondary vascular tissue and tetrarch primary xylem.

结果表明：不同直径大小的横走侧根均由周皮、次生维管组织和四原型的初生木质部构成。