不同生长年份移山参根的比较解剖学研究

采用石蜡制片法、显微观察生长8年、12年和16年的移山参主根中部的组织结构,并以4年生栽培参(二马牙)和西洋参为对照进行比较分析。结果表明,移山参主根结构由周皮和次生维管组织组成。不同生长年份的移山参主根结构具有一定差异:随生长年份的增长,木栓层细胞体积变小,排列趋于紧密;栓内层草酸钙结晶越来越少;分泌道均为3轮,但平均口径逐渐减小;韧皮部外侧和木质部靠近根中央处的薄壁组织的裂隙逐渐增大;韧皮部与木质部的面积比则不断下降;12年、16年生移山参主根次生木质部中导管数量和层数明显多于8年生。PAS 反应表明淀粉粒含量在生长12年以后趋于稳定。表明通过观察移山参木质部与韧皮部的面积比和次生维管组织中木质部导管的数量及层数,可以初步判断移山参的生长年份。

Comparative Anatomical Study of the Roots of Transplanted Panax ginseng Plants Growing for Different Times

Histological structures of the central parts of the taproots of Panax ginseng plants that had grown for 8 years, 12 years and 16 years after their transplantation were observed by paraffin sectioning and microscopy and then compared with those of P. ginseng (the variety Ermaya) and P. quinquefolium plants that had planted for four years. The results showed that the taproots of transplanted P. ginseng plants consist of periderm and secondary vascular tissue. The taproots of transplanted P. ginseng plants growing for different times differed to a certain extent. As the plants grew for a longer time the cells in the phellem of the taproots become smaller in size and closer in arrangement and calcium oxalate crystal declined in quantity in the phelloderm of the taproots;all the taproots had three secretory canals but on average the calibers of the canals gradually become smaller; the parenchyma cracks in outer phloem and the xylem part near the root center gradually increased in size,and the area ratios of phloem to xylem continuously decreased; the vessel and vessel-layer numbers in secondary xylem of the transplanted P. ginseng plants growing for 12 years and 16 years were remarkably higher than those of the transplanted plants growing for 8 years.Periodic-Acid-Schiff reactions indicated that the contents of starch granules stabilized when the transplanted plants grew for 12 years or more than 12 years. These illustrated that the time for which a transplanted P. ginseng plant had grown could be preliminarily determined by observing the area ration of phloem to xylem and the vessel and vessel-layer number in secondary vascular tissue of the transplanted plant.