【作者】 白方坤；

【导师】 李景原；

【作者基本信息】 河南师范大学 ， 植物学， 2011， 硕士

【摘要】 丹参作为一味传统中药在我国沿用已久,始载于《神农本草经》,传统以丹参植物的根入药,因其根色红且形状似参而得名“丹参”。正品丹参来源于唇形科(Labiatae)、鼠尾草属(Salvia)植物丹参(Salvia miltiorrhiza Bge)的根。本文主要研究了丹参生长发育过程根的解剖结构和有效成分的相关性。主要内容如下:研究表明:根尖(root tip)指从根的顶端到着生根毛的部分。主根、侧根和不定根都有根尖。根尖在根的生长、根的吸收、根的分枝以及根的组织分化中都起着十分重要的作用。根尖可以分为根冠(root cap)、分生区(meristematic zone)、伸长区(elongation)和成熟区(maturation zone)四个部分。根冠位于根尖的最前端,是由薄壁细胞组成的一个保护根尖的帽状结构,覆盖在分生区之外,保护着幼嫩分生组织,当根向土层深处生长时,使分生组织不致于被土壤中细砂石所磨损。同时,根冠外层的细胞形成粘滑的胶质,使根在生长过程中容易深入土层。根冠细胞在根生长时,由于与土壤的磨擦,外部细胞不断脱落,而里面的分生组织细胞不断地进行细胞分裂补充到根冠中,使根冠始终保持一定的厚度。分生区也叫生长锥,位于根冠之上,大约长1mm,是顶端分生组织。分生区的细胞在植物的一生中始终保持分裂能力,根的其他结构都由分生区细胞分裂所产生。根的分生区由原分生组织和初生分生组织两部分组成。原分生组织位于最前端,细胞分化较少,在原分生组织的最前端有一团细胞,其分裂的频率明显低于周围的细胞,这一区域叫做不活动中心(quiescent center)。初生分生组织位于原分生组织的上方,细胞已出现初步的分化,根据细胞的形状、大小及液泡化程度的不同,将初生分生组织划分为原表皮、基本分生组织和原形成层三个部分。原表皮以后发育成表皮,原形成层位于中央,以后发育成维管柱,基本分生组织位于原形成层和原表皮之间,以后发育成皮层。伸长区在分生区的上方,细胞多已停止分裂。细胞液泡化程度增加,体积增大,并显著地沿根的长轴方向伸长,是根部伸长的主要动力;另外,伸长区的细胞已加速分化,最早的筛管和环纹导管开始出现,是分生组织向成熟结构的过渡区。由外形上来看,成熟区外部密生根毛,因此,又叫根毛区(root hair zone)。根毛区的细胞开始成熟,细胞已分化为筛管、导管以及薄壁细胞等各类成熟组织,因此这一区叫做成熟区。根毛为植物的重要部分,根系分布在土壤中,根毛及其附近的表皮细胞具有吸收水分及无机盐类的能力。根毛是根表皮细胞的突出物,根毛呈筒状,表皮细胞与根毛间无横隔,细胞质沿细胞壁呈一薄层,中央为一大液泡,细胞核位于根毛的顶端。单位面积上大量生长根毛,大大的扩展了与土壤的接触面积,使得根系能充分吸收土壤中的水分和无机盐类。同时也发现根毛的形成与外界环境有关。丹参的根、茎、叶中均含有水溶性成分。叶中水溶性成分含量由高到低依次为丹参素>咖啡酸>原儿茶醛。在生长期中,丹参素、咖啡酸含量在6月份最高,以后逐渐减少,12月降到最低;原儿茶醛的含量变化不大;叶的发育过程中,水溶性成分含量逐渐降低。茎中几乎不含水溶性成份。根中丹参素含量最高,原儿茶醛次之,咖啡酸最低。在生长期中,丹参素含量在7月最高,且6～9月含量较为稳定,9月以后丹参素含量逐渐降低;原儿茶醛、咖啡酸的含量在7、8、9月较为稳定,以后逐渐降低,至12月降至最低。根中有效成分含量与根的粗度无相关性,随着皮部与木质部厚度之比增大,有效成分含量有增加的趋势。丹参酮ⅡA和丹参酮I在生长季节的含量变化规律呈“单峰”曲线,丹参酮ⅡA在7月含量最高,丹参酮I在5月含量最高。更多还原

【Abstract】 Research was conducted on Salvia miltiorrhiza, a traditional medicinal plant, to investigate the effects of irradiation and shade on the concentration of catalpol in seedlings and rhizosphere. The plants were grown under three irradiances: full light, partial shade (50% full light), and irradiation. The Salvia miltiorrhiza seedlings were harvested and the hydroponic culture solution in the containers was collected on days 3, 6, 9, 12, 15 after treatment respectively for determination of catalpol. The results showed that irradiation increased the concentration of catalpol in leaves rapidly at the early stage. Then, instead of increasing, the concentration of catalpol decreased a little. In contrast, the catalpol content in Salvia miltiorrhiza leaves was reduced under partial shade. Similar trends were observed in roots and stems of Salvia miltiorrhiza under irradiation and shade. The concentration of catapol in medium in which full-light, shade and UV-irradiated seedlings were grown all increased with time. But the concentration of catapol in medium of irradiated seedlings was greater than that of full-light seedlings, the concentration of catapol in medium of shade seedlings is lower than that of full-light seedlings. Therefore, irradiation increased both production of catalpol in Salvia miltiorrhiza seedlings, and secretion of catalpol into Salvia miltiorrhiza rhizosphere. In contrast shading decreased not only production of catalpol in Salvia miltiorrhiza seedlings, but also secretion of catalpol into Salvia miltiorrhiza rhizosphere.Irradiation increased the concentration of catalpol in leaves of Salvia miltiorrhiza seedlings rapidly at the early stage. Then, instead of increasing, the concentration of catalpol decreaced a little. The production of catalpol was, therefore, probably increased at the early stage by irradiation due to induceing stress response of plant, increaceing more plant secondary metabolites to guard against irradiation damage. However, a further extension of time to radiation, the leaves were damaged by the radiation, which affected not only the photosynthetic efficiency but the production of the secondary metabolites. Therefore, a further extension of time to UV radiation, the catalpol content in Salvia miltiorrhiza leaves did not increase significantly, or even decreased. In contrast, the catalpol content in Salvia miltiorrhiza leaves was reduced under partial shading, suggesting that shading affected photosynthesis, then the synthesis of secondary metabolites. There was an accumulation of catalpol in the medium in which Salvia miltiorrhiza seedlings were grown. As described in the Materials and methods section, in the present experiments only R. glutinosa roots were immersed in the medium. Thus, the Salvia miltiorrhiza seedlings probably secrete catalpol from their roots into the medium. The results described in the present research showed that the concentration of catalpol in the medium in which UV-irradiated seedlings were grown was greater than that in the medium in which full-light seedlings were grown.There are few reports on the effect of irradiation on catalpol concentration, but it was noted that irradiation increased not only production of momilactone B in rice seedlings but also secretion of momilactone B into rice rhizosphere. On the contrary, the concentration of catalpol in the medium in which shaded seedlings were grown was lower than that in the medium in which full-light seedlings were grown. These results suggest that irradiation increased both production of catalpol in Salvia miltiorrhiza seedlings, and secretion of catalpol into Salvia miltiorrhiza rhizosphere. In contrast shading decreased not only production of catalpol in R. glutinosa seedlings, but also secretion of catalpol into Salvia miltiorrhiza rhizosphere. So if high concentration of catalpol in soil is the reason for Salvia miltiorrhiza continuous cropping obstacle, intercropping with tall crop can be taken in agricultural production to shade Salvia miltiorrhiza, so as to reduce secretion of catalpol into Salvia miltiorrhiza rhizosphere.更多还原