In vitro regeneration of the colorful fern Pteris aspericaulis var. tricolor via green globular bodies system

Abstract

Pteris aspericaulis var. tricolor T. Moore ex Lowe is a fern species with colorful fronds, potentially used as an ornamental plant. In the present study, we reported the establishment of in vitro regeneration of P. aspericaulis var. tricolor via green globular bodies (GGBs) system by using in vitro juvenile sporophytes as explants. GGB induction, multiplication and plantlet regeneration media, as well as the influence of light-emitting diodes (LEDs) on GGB multiplication and plantlet regeneration were investigated. The highest GGB induction frequency obtained on the medium supplemented with 2.73 μM thidiazuron (TDZ). The medium containing 1.32 μM 6-Benzyladenine (BA) was the optimum for GGB multiplication. GGB cultivated on 1/4 MS medium with the addition of 0.1% (w/v) activated charcoal (AC) behaved the highest differentiation frequency (94.44%), and 1/4 MS medium without AC was the most effective for plantlet growth. The light quality of LEDs (white, blue, red) had no effect on GGB multiplication and differentiation, but remarkably affected the plantlet height. Red LEDs promoted the petiole elongation, while blue LEDs inhibited it. Morphological and histological observation showed that GGBs consisted of a cluster of single GGBs with meristem and scale-like structure, and new single GGBs were efficiently initiated from the epidermal cells in top meristem of GGBs.