Optimizing shoot culture media for Rubus germplasm: the effects of NH4+, NO3- and total nitrogen
Optimization of in vitro mineral nutrition in culture medium is often overlooked as a means for improving micropropagation, despite the fact that mineral nutrients greatly affect morphological and physiological growth and development. Non-optimal mineral concentrations in culture media may result in stunted growth and physiological disorders such as hyperhydricity, leaf chlorosis, shoot tip necrosis, and leaf spots. The most common nitrogen (N) forms used in tissue culture growth media are NO3− and NH4. The effects of N may be dependent on either the total N amount or the proportion of NO3− and NH4+. Modeling studies on the effects of mineral nutrition on growth and development of micropropagated red raspberry indicated that the amounts and ratios of nitrogen coumpounds were very important. In this study, ammonium and nitrate nitrogen were varied to determine the best growth responses. Eight red raspberry cultivars and one wild red raspberry were initially evaluated for overall quality, shoot length, proliferation, leaf characteristics and physiological disorders. The concentration of nitrate was the most significant factor for improved shoot quality of most cultivars. The amount of ammonium and interactions between ammonium and nitrate influenced most shoot growth responses. Tests of 10 additional cultivars and species showed that the five best treatments from the first group tested were also the most effective for the wider range of germplasm. Most of this Rubus germplasm grows well on a medium with increased calcium, magnesium and phosphorous and the standard nitrogen components while others are greatly improved by altering the total nitrogen or the ammonium to nitrate ratios.
Sukalya Poothong, Barbara M. Reed. Optimizing shoot culture media for Rubus germplasm: the effects of NH4+, NO3–, and total nitrogen. In Vitro Cellular & Developmental Biology-Plant 52: 265-275, 2016.
In vitro propagation and cardenolide profiling of Digitalis ferruginea subsp. schischkinii, a medicinally important foxglove species with limited distribution in Northern Turkey
Turkey has a wide-range of floral richness, and of the plant species, genus Digitalis L., commonly known as the “foxglove”, are the main sources of cardenolides, which possess different pharmacological properties effective against several pathological conditions. The main goal of the study was to develop an efficient in vitro regeneration protocol in a foxglove species having limited distribution (D. ferruginea subsp. schischkinii). Furthermore, cardenolide profiling of populations distributed naturally at different locations along the Black Sea region (Northern side of Turkey) was estimated. In addition, a comparison of selected cardenolide spectra was made between regenerants (in vitro produced plantlets) and the plants grown in natural habitats.
In this study, we claimed the importance of population selection traveling around 10,000 km throughout the study, for consistent plant propagation in order to achieve the desired phytochemical profile in the resulting clones. Using in vitro cultivation techniques, medicinal plants may be propagated on the basis of their chemotypic variation at the population level; thus, these techniques may contribute important information for the production of natural compounds having medicinal and economic value without disturbing natural habitats of the source plants. This point of view is especially very important for biennial plants, which do not set seed until the second year of growth as seen in many foxglove species. In this present work, a straightforward and very effective regeneration protocol (i.e. 6 shoots production from hypocotyl segments after 4 wk cultivation in vitro) was established for the first time in D. ferruginea subsp. schischkinii based on the cardenolide profiles of natural populations. This work might also be applicable for the domestication purpose of other foxglove species.
Buhara Yücesan, Aliyu Mohammed, İsmail Eker, Muhammad Sameeullah, Öznur Demir-Ordu, Cansu Cihangir, Nevin Şahbaz, Özge Kaya, Frieder Müller-Uri, Wolfgang Kreis, Ekrem Gürel. In vitro propagation and cardenolide profiling of Digitalis ferruginea subsp. schischkinii, a medicinally important foxglove species with limited distribution in Northern Turkey. In Vitro Cellular & Developmental Biology-Plant 52: 322-329, 2016.