Environ Exp Biol (2019) 17: 169–177

In vitro regeneration and propagation from fasciated stems of Vitex rotundifolia

Abstract

An efficient plant proliferation and regeneration system via fasciated stems was established for the first time in Vitex rotundifolia L. Aseptic nodal segments were used as explants and cultured on Murashige and Skoog medium supplemented with different plant growth regulators alone and in different combinations to investigate the induction, proliferation, axillary shoot initiation and elongation from fasciated stems and subsequent regeneration. The obtained results show that the growth of fasciated stems can be regulated by cytokinins. A higher concentration of cytokinins induced both the formation of axillary shoots from normal stems and the development of fasciated stems. Anatomical analyses revealed that fasciated stems (5 to 25 mm wide) were much wider than normal in planta shoot stems (2 to 3 mm wide). The pith cells of fasciated stems developed laterally to 0.05 – 0.08 mm in width, while normal stems were usually 0.02 to 0.04 mm in width. Flow cytometry indicated no obvious changes in chromosomes among the four types of shoots. This is the first report on the development of axillary shoots from fasciated stems in V. rotundifolia tissue culture. Our protocol serves as a new form of clonal plant regeneration.