Carbon/Nitrogen Ratio and Greening and Protocorm Formation in Orchid Callus Tissues

Abstract

Callus tissues of orchid Aranda Tay Swee Eng ( Archnis Lily Chong × Vanda Piha Moon) were cultured in Vacin and Went's medium that contained between 0% and 2% fructose. The chlorophyll content of callus tissues measured after 31 days of incubation ranged from 59 to 133 µg·g –1 tissue and was inversely proportional to the C/N ratio of the initial culture medium. The number of protocorm developed on callus tissue was instead inversely proportional to the residual C/N ratio of the 31-day-old culture medium and ranged from 13 to 74. The interrelationship of the C/N ratio of the medium, chlorophyll content, and protocorm formation in Aranda callus tissues is discussed.