Amending storage vessel and media increase transfer interval of Musa spp. tissue culture plantlets

Abstract

Musa spp. are some of the most important fruit food crops in the world. The USDA-ARS TARS maintains a Musa spp. germplasm collection of 164 accessions in field plots and in medium-term storage in vitro. Accessions maintained in vitro require routine sub-culturing as nutrient medium is lost due to uptake by the plant. Culture transfer intervals occur every six months and the transfer process is a resource and time consuming effort. To lengthen the transfer interval, an experiment was conducted to evaluate storage medium modifications and storage vessels on four Musa spp. accessions. Treatments consisted of glass tubes, glass tubes with Parafilm®, and plastic culture bags with three medium alterations: Murashige and Skoog (MS) medium, % strength MS and MS with 4% D-mannitol. Treatment effects were estimated by measuring plantlet's overall appearance, shoot and leaf number, and rooting on a monthly basis. All medium formulations for all four accessions, in glass tubes with Parafilm® and in culture bags showed significantly increased sub-culture interval times. The % MS treatment initially retarded plantlet development and showed the shortest storage time for all accessions. Storage time could be extended to 12 months with tissue culture bags, and to over 16 months with sealed tubes. The simplicity of using culture bags for distribution and the decrease in contamination during storage in bags were identified as additional advantages.