Auxin-induced plantlet formation of Dendrobium stratiotes x Dendrobium lineale hybrid in in vitro culture

Native species orchids, as a source of genetic diversity, can be used in crossing activities to produce hybrid orchids. Dendrobium is a type of orchid in great demand and of high economic value because of its unique flower shape and colour. Developing new varieties through interspecific crossings has produced a D. stratiotes × D. lineale hybrid that successfully germinated in in vitro culture. This experiment was carried out to study the effect of auxin type and concentration on D. stratiotes × D. lineale hybrid orchid plantlet development in in vitro culture, as well as to determine the best type and concentration of auxin to stimulate D. stratiotes × D. lineale hybrid orchid plantlet development. The results showed that the number of shoots formed and the root length of the D. stratiotes × D. lineale hybrid were controlled by the interaction between auxin type and its concentration. Adding 15 µM IBA produced the most shoots, 16.33 shoots per explant. In addition, NAA application resulted in the longest shoots (1.38 cm shoot per explants) and most roots (11 roots per explants) at 8 weeks after planting, which were significantly different from those produced by IAA or IBA.