Long-Qing Chen

Callus Induction and Plant Regeneration from In Vitro Cultured Leaves, Petioles and Scales of Lilium Leucanthum (Baker) Baker

ABSTRACT Lilium leucanthum is a high-value ornamental and medicinal plant in China. The plant has low propagation rate in nature; therefore, identification of a suitable system for in vitro propagation is needed. The aim of current study was to identify a suitable system for optimum callus induction and plant regeneration from in vitro cultured leaves, petioles and scales of L. leucanthum. Bulblets regeneration was tested on MS medium supplemented with different concentrations of BA and NAA. The highest frequency of regeneration (96.7%) and the largest mean number of bulblets per scale (3.07) were obtained on MS medium containing 0.5 mg l−1 BA and 0.1 mg l−1 NAA. In vitro cultured scale explants showed great ability to induce callus, followed by in vitro cultured petioles and leaves. MS medium with 1.0 mg l−1 BA and 1.0 mg l−1 2,4-D was found to be optimal for callus induction from in vitro leaves and petioles with the highest induction percentages of 79.6% and 83.3%, respectively. MS medium containing 0.5 mg l−1 BA and 1.0–3.0 mg l−1 2,4-D was found best for callus induction from scales with the highest percentage (98.3%). The largest number of bulblets was regenerated (23.9) from 1.0 g of fresh callus cultured on MS supplemented with 0.5 mg l−1 BA and 0.2 mg l−1 NAA. The number of roots per plant was fewer and the length of roots was greater on the rooting media with AC compared to the media without AC; half-strength MS medium with 0.05 mg l−1 NAA was more suitable for rooting. After acclimatization, transplanted plantlets grew normally under greenhouse conditions.

Properties of Natural Fibers from the Abaxial Side of Fireweed (Gerbera delavayi) Leaf Blade for Manual Spinning

ABSTRACT Natural plant fibers obtained from the abaxial side of fireweed (Gerbera delavayi) leaf blade were systematically studied. Fireweed fibers were manually dismantled from hot-bath-treated, refrigerated, or untreated leaves and evaluated for different properties. In terms of the collection method, treatment with hot bath exhibited the highest efficiency. As for chemical composition, that of raw (untreated) fireweed fibers was similar to that of cotton, except for wax content that was four times higher in fireweed fibers that in cotton fibers. Fireweed fiber generally exhibited low values of length (6.5 mm), fineness (0.5 dtex), tenacity (0.7 cN/dtex), density (0.9 g/cm3), and crystallinity (14.6%) but similar elongation at break and moisture regain to those of cotton. Furthermore, fireweed fibers showed a smooth surface, soft texture, and water impermeability. After hot-bath treatment, fibers showed 20% lower wax component but higher thermal stability than raw fibers. The small size hindered the fibers from achieving the desirable standard of spinning and weaving by modern machine, but these unique cellulose fibers can be used for manual textile application without any chemical treatment.