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

Abstract

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 )1 sorbitol in combination with 30 g l )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 )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 )1 , despite the high osmolarity of monosaccharide media (c. 650 m Osm kg )1 , equivalent to )1.6 MPa, compared to 380 m Osm kg )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 )1 , not by increasing the monosaccharide supply. Implications of the findings for Narcissus micropropagation are discussed.

Effect of radiation on regeneration of Chinese narcissus and analysis of genetic variation with AFLP and RAPD markers

“…The first adventitious bud was observed 31 days after inoculation, and then many buds appeared. After 65 days in vitro culture, tiny bulb-like structures appeared at the base of the shoots, which were also observed in some other studies (Santos et al 1998;Staikidou et al 2005). The average number of shoots initiated per explant was 5.42, and the best explant had 16 buds in one twin-scale.…”

Effects of sucrose and plant growth regulators on acetylcholinesterase inhibitory activity of alkaloids accumulated in shoot cultures of Amaryllidaceae

“…For example, the addition of sucrose increased survival of the explants, with high sucrose concentrations inducing better organogenesis and decreasing callusing. This is in agreement with previous results where the addition of sucrose to the nutrient medium also improved bulb development in Narcissus cultivars (Staikidou et al 2005;Chow et al 1992) and in L. aestivum (Berkov et al 2009a, b).…”

Reduced temperature, elevated sucrose, continuous light and gibberellic acid promote corm formation in Watsonia vanderspuyiae

“…The two major hypotheses are: (1) increasing carbohydrate levels results in the abundant availability of energy (improved supply) that can be used for induction and growth; and (2) increasing carbohydrate levels results in the increase in medium osmolarity, hence creating a 'stress' type environment, that leads to storage organ induction as an avoidance response to a perceived unfavourable climate. This question has only really been investigated by Staikidou et al (2005) on Narcissus 'St. Keverne' and 'Hawera'.…”