Production of Disease Free Rumohra adiantiformis (Leatherleaf Fern) Using In Vitro Propagation

Abstract

This study investigated the use of rhizome tips as explants in regenerating disease-free plantlets of Rumohra adiantiformis (G. Frost) using the micropropagation technique. Rhizome tips of 0.5 cm, 1 cm, 1.5 cm, and 2 cm in length, and with and without outer skin were used as explants.The highest regeneration rate (30%) was achieved with an explant size of one centimetre when the outer skin was not present in rhizome explants. Rhizome tips produced complete plantlets in Murashige and Skoog (MS) medium without any growth regulators in 80 - 90 days of culture initiation. In vitro multiplication of disease-free plants was achieved by culturing four months old in vitro plantlets in the MS medium supplemented with 2 mg/L Benzyl Amino Purine (BAP) and 0.1mg/L Naphthalene Acetic Acid (NAA). Plantlets produced clusters of shoot primordia which are known as green globular bodies (GGB) in the multiplication medium, 10 weeks after culturing. Plantlets were obtained by culturing 2-3 mm size GGB segments in the basal medium without any plant growth regulators. Disease indexing of the in vitro derived plantlets verified that at in vitro level 60% of the plantlets obtained from the rhizome tips of one centimetre were free from bacterial and fungal diseases.