细胞分裂素对川牛膝幼苗根生长发育影响的研究

Study on the effects of cytokinin on the growth and development in the seedling root of Cyathula officinalis Kuan

目的:比较不同浓度6-BA对川牛膝幼苗根生长发育的影响,以进一步探究川牛膝"根粗壮、分支少"的品质特征形成机制。方法:以细胞分裂素6-BA培育31 d后的川牛膝幼苗为研究对象,对其根进行形态参数统计和显微结构观察,并对其内源激素、初级代谢产物采用酶联免疫提取法和植物试剂盒进行含量测定。结果:随着6-BA浓度上升,平均主根长度、平均侧根数均显著减少,而平均主根直径与根木质部面积则明显增加。内源激素(赤霉素GA、玉米素ZT、生长素IAA、脱落酸ABA)含量则分别在Z-2、Z-6浓度时达到最大值,含量显著高于其他浓度。初级代谢产物(可溶性糖、淀粉、可溶性蛋白)含量随着6-BA浓度升高而逐渐增大,且均在Z-10浓度时达到峰值。相关性分析则显示ZT、ABA与平均主根长度和平均侧根数均呈负相关,初级代谢产物含量和ZT、GA则与平均主根直径呈正相关。结论:高浓度的6-BA通过提高ZT、ABA含量而显著抑制川牛膝幼苗主根长度增加和侧根发育;对主根直径增粗则具有显著促进作用,体现在川牛膝幼苗根木质部面积增大和ZT、GA以及初级代谢产物含量的增加上。

Objective:To compare the effects of different concentrations of 6-BA on the root growth and development in the seedling root of Cyathula officinalis Kuan to further explore the formation mechanism of the quality characteristics of Cyathula offcinalis Kuan"strong roots and few branches".Method:In this experiment,seedlings of Cyathula officinalis Kuan after 31-day incubation with cytokinin(6-BA)were taken as the research object.The morphological development indexes and microstructure of the roots were observed.The endogenous hormones and primary metabolites were determined by enzyme-linked immunoextraction and plant kit.Result:With the increase of 6-BA,the average main root length and the average number of lateral roots decreased significantly,while the average main root diameter and root xylem area increased significantly.The content of endogenous hormones(gibberellin GA,zeatin ZT,auxin IAA,abscisic acid ABA)reached their maximum values at the concentrations of Z-2 and Z-6 respectively,which were significantly higher than other concentrations.The content of primary metabolites(soluble sugar,starch,soluble protein)gradually increased with the increase of 6-BA and all reached a peak at the concentration of Z-10.Correlation analysis showed that ZT and ABA were negatively correlated with the average main root length and the average number of lateral roots,while the primary metabolite content and ZT and GA were positively correlated with the average main root diameter.Conclusion:High concentration of 6-BA can significantly inhibit the increase of the main root length and lateral root development of the seedling root of Cyathula officinalis Kuan by increasing the content of ZT and ABA.It has a significant promotion effect on the thickening of the main root diameter,which is reflected in the increase of the xylem area and the content of ZT,GA,primary metabolites in the seedling root of Cyathula officinalis Kuan.