人参根系分泌物对其根源愈伤组织化感效应研究

Study on Allelopathic Effect of Ginseng Root Exudates Against Its Root Callus

目的:探讨人参根系分泌物对其根源愈伤组织生长的影响,为阐明人参化感作用机理及连作障碍提供理论依据。方法:采用含栽参土壤提取物80、40、20、10、5 gDW/mL的MS培养基对人参根源愈伤组织进行培养,选取适宜浓度根系分泌物对其根源愈伤组织丙二醛含量和DNA含量的化感效应进行研究,对处理不同时间的根源愈伤组织进行石蜡切片的观察。结果:在接种培养1 d后,丙二醛含量迅速增加,与对照差异极显著(P<0.01),而后又逐渐降低。DNA含量随培养时间的增加而逐渐降低,并在培养1 d时就与对照差异极显著(P<0.01),通过石蜡切片观察可知细胞核数量随培养时间延长而逐渐减少,解体消失。结论:人参根系分泌物的化感作用具有破坏人参根源愈伤组织膜的功能,影响细胞核数量,使细胞分裂和生长受阻,抑制其根源愈伤组织生长。

Objective：To study the effect of ginseng root exudates against its root callus and provide theoretic basis for allelopathic mechanism and continuous cropping obstacle.Methods：We cultured ginseng root callus with MS culture medium whose concentration was equal to soil concentration of 80,40,20,10,5 gDW/mL and chose the optimum concentration for further study on allelopathic effect of ginseng root exudates against its root callus content of MDA and DNA.The root callus which was treated at different time was observed with paraffin slice method.Results：The content of MDA increased quickly after cultured one day and was significantly different from control（P〈0.01）,then gradually reduced.The content of DNA gradually reduced with culturing time and was dramatically different in the treatment（P〈0.01）.The nucleolus gradually decreased,disaggregated and disappeared.Conclusion：The allelopathy of ginseng root exudates can destroy ginseng root callus membranous function and influence the amount of nucleolus.The cell division and differentiation are checked and the growth of ginseng root callus is inhibited.