In vitro regeneration from mature leaf explants of Pelargonium rapaceum (L.) L’Hérit

Methods to regenerate whole plants from mature leaf explants of Pelargonium rapaceum (L.) L’Hérit were established. To optimize shoot induction, leaf explants were cultured on media containing different types and combinations of plant growth regulators. Growth was initiated within 17–24 days culture, and included callus formation, and root or shoot organogenesis ranging from 20 to 100% regeneration. Shoots were induced only when explants were cultivated on MS medium containing a combination of NAA and kinetin, NAA and BAP, IAA and Kinetin, or IAA and BAP. On media containing NAA and BAP, dark incubation was critical for efficient direct shoot regeneration from explants. Direct shoot formation and the highest number of shoots per explant (17.6) were obtained from leaf explants cultured in the dark for 30 days on MS medium containing 0.1 mg l⁻¹ NAA and 0.1 mg l⁻¹ BAP. Shoots cultured on MS medium containing 0.1 mg l⁻¹ NAA formed tuberous roots with microtubers within 42 days. Healthy regenerated plants were acclimated and transferred to a greenhouse.     

Natural dyeing of cotton with <Emphasis Type="Italic">Xylocarpus granatum</Emphasis> bark extract: Dyeing,fastness, and ultraviolet protection properties

In this research we investigated the dyeing of cotton fabrics with extracts of Xylocarpus granatum, a mangrove plant with a long history of use in leather tanning and textile dyeing. X. granatum bark was extracted and spray-dried, yielding a tannin-rich, reddish-brown powder. This powder proved a suitable colorant for the natural dyeing of cotton with promising color fastness properties to wet treatments (washing, water, sea water, and perspiration), hot pressing, crocking, and light exposure. However, the dye alone produced only weak levels of coloration and therefore metallic salt mordants were employed to improve the color strength, through the formation of insoluble tannate complexes. The resulting fabric K/S values were dependent on the mordant used and exhibited the following trend: ferric sulfate > sodium dichromate > copper sulfate > potassium aluminum sulfate > no mordant, for fabrics exposed to mordants before and after dyeing. Mordanting resulted in slight variations in shade and color fastness. In most cases, the color fastness properties were preserved, except for color fastness to light and hot pressing, for which lowered ratings were found for some mordants. Stiffness and mechanical performance were not greatly affected by dyeing or mordanting, except for sodium dichromate mordanting which significantly stiffened and weakened the fabric. The ultraviolet protection factor (UPF) of all the dyed samples achieved the maximum (50+) level, highlighting the excellent UV shielding properties of the fabric. Overall, X. granatum bark extract is a promising, effective colorant for the natural dyeing of cotton in terms of appearance, fastness, and physical characteristics.