Factors affecting shoot proliferation and vitrification in Digitalis obscura cultures

• Published in: In vitro cellular & developmental biology. Plant 1992-07, Vol.28P (3), p.121-124
• Main Authors: Lapena, L. (University of Valencia, Valencia, Spain), Perez-Bermudez, P, Segura, J
• Format: Article
• Language: English
• Subjects: Adventitious shoots; Agronomy. Soil science and plant productions; Biological and medical sciences; Biotechnology; Cardenolides; CELL DIFFERENTIATION; Chlorophylls; CULTIVO DE TEJIDOS; CULTURE DE TISSU; DIFERENCIACION CELULAR; DIFFERENCIATION CELLULAIRE; DIGITALIS; DISPONIBILIDAD DE NUTRIENTES; ELEMENT NUTRITIF DISPONIBLE; EMBRIONES VEGETALES; EMBRYON VEGETAL; EXPLANT; EXPLANTES; EXPLANTS; Fundamental and applied biological sciences. Psychology; HIPOCOTILOS; HYPOCOTYLE; HYPOCOTYLS; Lignin; Liquids; NUTRIENT AVAILABILITY; PLANT EMBRYOS; Plant growth regulators; Plant physiology and development; Plants; REGENERACION; REGENERATION; REGENERATIVE ABILITY; Solids; STEMS; TALLO; TIGE; TISSUE CULTURE; Tissue cultures, protoplasts; VITRIFICACION; VITRIFICATION
• ISSN: 1054-5476; 1475-2689
• DOI: 10.1007/BF02823059

Variations of composition and consistency of the culture medium and time of exposure to growth regulators werė assayed to optimize normal caulogenic response of Digitalis 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 macronutrients of Murashige and Skoog did not significantly affect the bud-forming capacity of the explants. In contrast, a drastic inhibitory effect on both bud formation and shoot elongation was produced when NH₄NO₃ was omitted. Reduction of NH₄NO₃ to one-half or one-fourth of the level of the original formulation not only increased the bud-forming capacity of D. obscura hypocotyls but also resulted in less vitrification. Modifications of time and method of exposure to growth regulators neither improved the multiplication rates nor overcame vitrification. Cardenolide content was lower in vitrified than in normal cultures and coincided with an overall reduction of photosynthetic pigments, lignin, and dry matter.