2019 ASHS Annual Conference

Current commercial production of anthurium in Hawaii is limited by the availability of micropropagated planting material. Anthurium andraenum Hort. ‘New Pahoa Red’ is the most widely-grown cultivar in Hawaii and propagules for this variety are in great demand by commercial growers. Conventional micropropagation of anthurium includes multiplication of axillary buds in liquid culture. The use of semi-automated systems such as temporary immersion systems has been adopted for commercial micropropagation in a number of crops due to its ease of use, ability to produce high numbers of micro-plantlets and bypass physiological disorders caused by submerged culture. This study aimed to develop a protocol for anthurium micropropagation using the Recipient for Automated Temporary Immersion (RITA) bioreactor. Nodal segments (two axillary buds per explant) were excised from in vitro ‘New Pahoa Red’ microplants and cultured in medium under RITA or in 125 mL Erlenmyer flasks using modified Kunisaki (1982) medium. After 6 weeks of culture, explants in the RITA bioreactor produced 25 shoots per vessel compared to 6.2 shoots from the standard method. Likewise, a higher percentage of explants with induced shoots was also observed in the RITA system (85%) compared to the standard vessel (21%). In a second experiment to optimize immersion parameters for the RITA bioreactors, nodal explants were subjected to various combinations of immersion time (0, 5, 10, 20 minutes) and volume (10 or 20 ml) of medium per explant. The average number of shoots induced per explant was not affected by the volume of media provided per explant, although immersion time was highly significant. The highest average number of shoots induced per explant was observed under with 10 minutes immersion, which produced an average of 2 shoots per explant. Interaction effects of immersion and medium volume were highly significant for average number of shoots per vessel unit and percentage of explants forming shoots. Ten minutes immersion and 20 ml per explant produced the highest average number of shoots (20.3) produced per vessel unit and the highest percentage of explants forming shoots (96.6%). Inclusion of RITA can supplement and increase the production of anthurium micropropagules.