龙眼剥皮再生的解剖学研究

ANATOMICAL STUDIES ON REGENERATION AFTER RINGING OF DIMOCARPUS LONGAN

龙眼(Dimocarpus tongan Lour.)茎干经过大面积环剥,都能再生出新皮。环剥初期,愈伤组织都由近暴露面的射线细胞产生,稍后,其他未成熟木质部细胞也参加愈伤组织的形成,这些愈伤组织一般在靠近表面都可发生木栓形成层,以后迅速形成正常的周皮。在愈伤组织与木质部交界处的未成熟木质部细胞发生维管形成层。新发生的形成层正常地向外分化出次生韧皮部,向内分化出次生木质部。初期有些原来的射线将新形成层带分割成许多小区,二个月后,由于新的形成层不断平周活动,逐渐将形成层连成一圈,以后基本上与正常树皮维管组织的发育一样。

The trunk of Dimocarpus tongan Lour, following an extensive length of copletely girdling could regenerate new bark. Several days after girdling, the ray cells near the surface dilated and proliferated outward to form callus. Then other immature xylem cells rehabilited the ability of cell division and took part in the formation of callus. A cork cambium developed near the surface of callus, and then developed normal periderm rapidly. The immature xylem cells developed vascular cambium at the place where callus bound xylem. The newly formed cambium can normally produce phloem outwardly and xylem imwardly. At early stage some former ray devided the new banding into many segments. However, two months later, the new cambium activity proceeded periclinally so as to establish a complete ring of cambium zone. Subsequent differentiation of newly formed cambium followed the normal pattern of vascular tissue development in the plant.