Genotypic Variability of de novo Shoot Morphogenesis of Brassica oleracea in vitro in Response to Ethylene Inhibitors and Putrescine

• Published in: Journal of plant physiology 1999-10, Vol.155 (4), p.598-605
• Main Authors: Pua, Eng-Chong, Deng, Xiaoyun, Tiong-Chew Koh, Andy
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biotechnology; Brassica oleracea; ethylene; Eukaryotic cell cultures; Fundamental and applied biological sciences. Psychology; In vitro propagation: entire plant regeneration from tissues and cell cultures; Methods. Procedures. Technologies; Plant cells and fungal cells; polyamines; shoot regeneration; tissue culture
• ISSN: 0176-1617; 1618-1328
• DOI: 10.1016/S0176-1617(99)80060-1

Effects of ethylene inhibitors and exogenous putrescine on the shoot regeneration capacity of cultured hypocotyl explants from 18 cultivars of cabbage, cauliflower and broccoli were investigated. All cultivars were poorly regenerative on Murashige and Skoog's medium supplemented with 0.5–1 mg · L −1 α-naphthaleneacetic acid in combination with 1–4 mg · L −1 benzyladenine. Shoot regeneration of some cultivars was enhanced by addition of 10 μmol · L −1 AgNO 3 to the medium. The presence of 10 μmol · L −1 aminoethoxyvinylglycine (AVG) or 10 mmol · L −1 exogenous putrescine was also beneficial to regeneration, whereas combining chemical treatment with vacuum infiltration had little effect. Explants of all three cabbage cultivars tested (‹Booming Spring›, ‹Eastern Riches› and ‹Summer Autumn›), when grown on AgNO 3 medium, produced significantly more ethylene than control explants, but there was no difference in the content of free polyamines (putrescine, spermidine and spermine) in both tissues. On the contrary, explants grown in the presence of AVG emanated lower ethylene during the three-week culture period. Furthermore, these explants also showed a significantly higher free putrescine content up to 7–10 days of culture, although the difference in free spermidine and spermine between AVG-grown and control explants was negligible. The results support the hypothesis that ethylene produced by explants often inhibits shoot regeneration in vitro.