Narcissus bulblet formation in vitro: effects of carbohydrate type and osmolarity of the culture medium

• Published in: Plant cell, tissue and organ culture Vol. 80; no. 3; pp. 313 - 320
• Main Authors: Staikidou, I, Watson, S, Harvey, B.M.R, Selby, C
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01-03-2005
• Subjects: Biological and medical sciences; Biotechnology; bulbs; cultivars; culture media; dose response; Eukaryotic cell cultures; Fundamental and applied biological sciences. Psychology; genetic variation; in vitro culture; in vitro regeneration; mannitol; methodology; Methods. Procedures. Technologies; micropropagation; Miscellaneous; Narcissus; nutrient use efficiency; ornamental bulbs, corms and tubers; osmolarity; Plant cells and fungal cells; shoots; sorbitol; sucrose; Culture medium; Monocotyledones; Vegetals; Osmolarity; Sucrose; bulb; Micropropagation; In vitro; cultivar effects; Angiospermae; Spermatophyta; Carbohydrate; monosaccharides; Narcissus; Amaryllidaceae
• ISSN: 0167-6857; 1573-5044
• DOI: 10.1007/s11240-004-1366-0

Shoot clump cultures of Narcissus cultivars St. Keverne and Hawera were used to investigate the effects of culture medium carbon supply, type of carbohydrate and osmolarity on in vitro bulblet development. Increasing the medium osmolarity using mannitol or sorbitol, which did not act as substrates for growth, failed to stimulate bulblet formation with either cultivar. An exception to this was a relatively small increase in total bulblet dry weight per culture, in the cultivar Hawera only, caused by adding 30 g l super(-1) sorbitol in combination with 30 g l super(-1) sucrose. Simultaneously increasing the medium osmolarity and carbon supply using the metabolisable carbohydrate sources, sucrose, glucose, fructose or an equimolar mixture of glucose and fructose stimulated bulblet production, total dry matter accumulation and partitioning into bulblets. At comparable levels of carbon supply up to 19.0 g l super(-1), bulblet development of both cultivars was similar with monosaccharide and sucrose media. This indicates that substrate supply is more important for bulblet development than osmolarity of the culture medium. The cultivar Hawera also showed similar responses to monosaccharide and sucrose media supplying 37.9 g C l super(-1), despite the high osmolarity of monosaccharide media (c. 650 m Osm kg super(-1), equivalent to -1.6 MPa, compared to 380 m Osm kg super(-1) for sucrose medium). However in St. Keverne total dry matter accumulation and dry weight per bulblet were further stimulated only by increasing the sucrose supply from 19.0 to 37.9 g C l super(-1), not by increasing the monosaccharide supply. Implications of the findings for Narcissus micropropagation are discussed.