An efficient in vitro method for mass propagation of a woody ornamental Ixora coccinea L.

Abstract

Various factors that affect culture establishment, shoot growth, proliferation and rooting of Ixora coccinea L., a woody shrub, were studied. Stem cuttings (decapitated shoot, three nodes) were the most suitable explants for multiple-shoot proliferation, and when cultured on a woody plant medium (WPM) containing 2.5 μM BA produced axillary shoots which branched repeatedly, yielding an average of 27 shoots per explant after 6 weeks in culture. Kinetin, 2-iP, zeatin and thidiazuron all induced multiple-shoot formation, but were less effective than BA. While the presence of IAA in the multiplication medium was detrimental to shoot proliferation, shoot growth was not affected by IAA. The production of large amounts of basal callus and vitrification of shoots were the major problems to be avoided in proliferating shoot cultures. Addition of TIBA to the multiplication medium markedly reduced basal callusing, while sealing the culture vessels with a fluorocarbon polymer (tetrafluoroethyleneperfluoroalkyl vinyl ether) film (Neoflon PFA film) almost completely eliminated vitrification. A reduction in the number of vitrified shoots was also achieved with AVG treatment. Following this protocol of using BA-supplemented WPM and Neoflon film, it would be possible to produce more than 100,000 plants from a single stem cutting in 1 year.