Li Z G, Cui K M, Yuan Z D, Liu S J
Sci Sin B. 1983 Jan;26(1):33-40.
The girdled trunk of Eucommia ulmoides, sometimes could not regenerate a new bark due to ringed surface necrosis. But, if an extension of 10cm of the bark on each end of the necrotic part was removed in time and re-covered with new bark taken from another tree, the re-covered bark and the newly girdled part could heal together one week after. Opposite to the necrotic surface the loose part of the re-covered bark regenerated callus from the phloem ray cells. If the re-covered part was very close to the necrotic surface, no callus was regenerated. However, many scattered tracheid-like elements derived from phloem were found. And then groups of cells including several tracheid-like elements were discernible. There was a ring of meristematic cells around that group of cells. Finally these meristems gradually became normal and had usual activities of vascular cambium.
杜仲的环状剥皮树干，有时会因环状表面坏死而无法再生新皮。但是，如果及时将坏死部分两端各10厘米长的树皮切除，并用取自另一棵树的新皮重新覆盖，重新覆盖的树皮和新环剥部分在一周后可以愈合在一起。与坏死表面相对，重新覆盖的树皮的疏松部分从韧皮射线细胞再生出愈伤组织。如果重新覆盖的部分非常靠近坏死表面，则不会再生愈伤组织。然而，发现了许多源自韧皮部的分散的管胞状细胞。然后可以辨别出包括几个管胞状细胞的细胞群。在那组细胞周围有一圈分生组织细胞。最后，这些分生组织逐渐恢复正常，并具有维管形成层的正常活动。
