Improving acclimatization through the photoautotrophic culture of coconut (Cocos nucifera) seedlings: an in vitro system for the efficient exchange of germplasm

• Published in: In vitro cellular & developmental biology. Plant Vol. 50; no. 4; pp. 493 - 501
• Main Authors: Samosir, Yohannes M. S, Adkins, Steve
• Format: Journal Article
• Language: English
• Published: Boston Springer-Verlag 01.08.2014; Springer; Springer US; Springer Nature B.V
• Subjects: acclimation; Acclimatization; air; Biomedical and Life Sciences; Carbon dioxide; Cell Biology; Chlorophyll; Chlorophylls; Coconuts; Cocos nucifera; Colleges & universities; Developmental Biology; Embryos; Germplasm; germplasm exchange; Greenhouses; in vitro culture; leaf area; Life Sciences; PHYSIOLOGY; Plant Breeding/Biotechnology; Plant cells; Plant Genetics and Genomics; Plant Sciences; Plant Tissue Culture; Plantlets; Plants; Seedling culture; Seedlings; Seeds; Sucrose; enrichment; Photoautotrophic culture; Coconut embryo culture; CO; International germplasm exchange
• ISSN: 1054-5476; 1475-2689
• DOI: 10.1007/s11627-014-9599-z

An in vitro photoautotrophic step based on the supply of CO₂-enriched air (1,600 μmol mol⁻¹) during the light phase and ambient air (350 μmol mol⁻¹ CO₂) during the dark phase has been used to promote the ex vitro establishment of coconut (Cocos nucifera L.) seedlings. The introduction of this step into a previously developed in vitro protocol was found to improve the quality of the seedlings (as assessed by fresh weight increase, physical stature, leaf area and thickness, stomatal density, and chlorophyll a content, and primary and secondary root production), the proportion of seedlings successfully transferred to soil (improvement from 40% to 100%) and achieved in a shorter time (reduction from 10 to 6 mo). Best results using this photoautotrophic growth step were obtained when a low medium concentration of sucrose (43.8 mM or lower) was used, when it was applied to seedlings that had already reached 4 or 5 mo of age in the in vitro culture step, and when seedlings were cultured in the photoautotrophic system for 2 mo or more before transfer to soil. Our improved protocol is more efficient and it reduces the cost per plant for the international exchange of coconut germplasm.