Improving the micropropagation efficiency of hybrid Dendrobium orchids with chitosan

• Published in: Scientia horticulturae 2010-05, Vol.124 (4), p.490-499
• Main Authors: Pornpienpakdee, Panisa, Singhasurasak, Ronnawich, Chaiyasap, Pongsathorn, Pichyangkura, Rath, Bunjongrat, Ruengwit, Chadchawan, Supachitra, Limpanavech, Patchra
• Format: Article
• Language: English
• Subjects: acclimation; Agronomy. Soil science and plant productions; Biological and medical sciences; cell differentiation; chemical structure; Chitosan; corms; culture media; Dendrobium; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Generalities. Genetics. Plant material; Genetic resources, diversity; Genetic variation; Genetics and breeding of economic plants; In vitro propagation; in vitro regeneration; micropropagation; mortality; nursery crops; oligomers; Orchid; ornamental plants; Plant material; plant tissues; plantlets; PLB; polymers; protocorm-like bodies; Protocorm-like body; shoots; somaclonal variation; Vegetative propagation. Micropropagation; Vegetative propagation. Sowing and planting. Harvesting
• ISSN: 0304-4238; 1879-1018
• DOI: 10.1016/j.scienta.2010.02.008

The appropriate chitosan types and concentrations for enhancing the in vitro micropropagation of Dendrobium ‘Eiskul’ were studied using 70, 80 and 90% N-deacetylated polymeric (P-70, P-80 and P-90) and oligomeric (O-70, O-80 and O-90) forms of crab ( Portunus pelagicus) chitosan. For the initial protocorm-like body (PLB) multiplication, the application of 10 mg/L of P-70 or 20 mg/L of P-90 was optimal, although 10 mg/L of P-80 and O-70 were also effective, and attained maximal PLB replication rates without increasing the detectable levels of somaclonal variation. However, during PLB-shoot induction, 10 or 20 mg/L of O-80 was the most appropriate chitosan and also induced further PLB formation. For plantlet regeneration, the addition of 10 mg/L of O-80 or P-80 gave the best quantity and quality, respectively, of plantlets. Finally, 20 mg/L of P-70 chitosan as a supplement during exflasking enhanced both the survival rate and the growth of the plantlets at one month after exflasking. Together, these data reveal a potentially beneficial and applicable protocol for commercial orchid micropropagation.