Search results for "Digitalis obscura"
showing 5 items of 25 documents
Cardenolide variation within and among natural populations of Digitalis obscura
1999
Summary Cardenolide content in 49 wild-growing Digitalis obscura plants from six natural populations on the Iberian Peninsula was determined by HPLC. Series A and B glycosides were the predominant cardenolides in all samples, but absolute values varied among and within populations. Hierarchic analysis of variance showed that the proportion of variation attributable to individuals was significantly higher than that attributable to population differences. Furthermore, analyses from greenhouse-grown plants, generated from seeds collected from selected parental genotypes, attributed nearly all the variability in cardenolide content to single plants. Some individual plants showed a leaf content …
Soil‐plant relationships, micronutrient contents, and cardenolide production in natural populations of Digitalis obscura
2004
The production of secondary metabolites by plants growing in natural populations is conditioned by environmental factors. In the present study, we have investigated the relationships among soil properties, micronutrients in soils and plants, and cardenolide production from wild Digitalis obscura (Scrophulariaceae) populations. Young and mature leaves and soil samples were collected in ten different populations, corresponding to three Mediterranean bioclimatic belts (Thermo-, Meso-, and Supramediterranean belts). Soil (total and EDTA-extractable) and leaf micronutrients (Fe, Mn, Zn, and Cu), and leaf cardenolide accumulation have been determined. Significant negative correlations were observ…
Factors affecting shoot proliferation and vitrification inDigitalis obscura cultures
1992
Variations of composition and consistency of the culture medium and time of exposure to growth regulators were assayed to optimize normal caulogenic response ofDigitalis obscura hypocotyls cultured in vitro. The effects of the culture conditions on physiologic changes related to vitrification of the regenerated plants were also investigated. Liquid medium increased the bud-forming capacity of the explants but induced buds failed to develop into shoots and showed symptoms of vitrification. On agar-solidified media, maximum multiplication rates were achieved with 0.7% agar. Increasing agar concentration reduced vitrification but lowered the propagation rate. Changes in the strength of the mac…
Isolation, culture and plant regeneration from mesophyll protoplasts of Digitalis obscura
1987
High yields of protoplasts were obtained from mesophyll tissue of Digitalis obscura L. Osmotic potential of the isolation medium and Ca2+ were important in obtaining a high viability of the preparations. In different culture techniques employed, liquid-over-agar-solidified medium was superior to liquid medium alone. Agar plating technique was ineffective. On Murashige and Skoog modified medium with casein hydrolysate and several indoleacetic acid and benzyladenine combinations, isolated protoplasts underwent sustained mitotic division and produced calli. The calli formed shoots when transferred to regeneration media. Regenerated shoots could be easily rooted and developed into whole plants …
Somatic Embryogenesis and Plant Regeneration from Hypocotyl Cultures of Digitalis obscura L.
1986
Summary Hypocotyl sections from 20-day-old seedlings of Digitalis obscura L. were used to examine the effect of IAA on somatic embryogenesis. Although embryogenesis was obtained with all IAA concentrations (0.1, 0.5 and 1 ppm) and under both illumination conditions tested (16 h photoperiod and darkness), incubation in photoperiod increased yield of embryos and shortened the embryo induction time. Optimum results were obtained with 1 ppm IAA. About 30 % of the embryos obtained developed into complete plantlets when transferred to basal medium without growth regulators.