And about a half month phellogen will begin to appear in the callus near the surface.

大约半个月后，在靠近表面的愈伤组织中出现木栓形成层。

youdao

And about a half month phellogen will begin to appear in the callus near the surface.

大约半个月后，在靠近表面的愈伤组织中出现木栓形成层。

youdao