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Chinese Agricultural Science Bulletin ›› 2018, Vol. 34 ›› Issue (28): 73-77.doi: 10.11924/j.issn.1000-6850.casb18050162

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Developmental Morphology of Regenerative Roots of Gentiana scabra

  

  • Received:2018-05-31 Revised:2018-07-13 Accepted:2018-07-24 Online:2018-10-11 Published:2018-10-11

Abstract: To understand the development process of regenerative roots on the excised roots, this study used conventional paraffin sectioning techniques to explore the replantation development process on the excised root after taking medicinal ingredients in Gentiana scabra. The results showed that the adventitious root structure of three-year-old G. scabra was composed of cortex and vascular cylinder. There was no periderm on the lateral cortex, and the formation layer did not form a complete ring. The secondary xylem was not developed. The adventitious roots on the excised root were formed by some cambium cells division, and then these cells divided rapidly to form the meristematic cell clusters. These meristematic cell clusters grew in a unidirectional polarity and formed root primordia directly. Multiple root primordia were formed from the excised root surface. The occurrence of adventitious roots, without the formation of callus, belonged to the type of direct organogenesis. The regeneration time of different plants was slightly different, and there was also developmental unsynchronization in the same root system. Under indoor condition, the regeneration cycle of reproductive roots took about 15 days. These roots could grow to a certain length and thickness in the autumn of that year. Therefore, the regenerative roots of rough gentian roots belong to the type of direct organogenesis. The meristematic cell masses originate from some cells near the formation layer. These regenerative roots can meet the harvesting standards after a growing season.