RAPID IN VITRO MULTIPLICATION OF ANTHURIUM USING TEMPORARY IMMERSION SYSTEM (RITA®)

Abstract

Anthuriums have been considered as the most important cut flower in Hawaii and have been consistently among the top floriculture products. Despite efforts to improve in vitro propagation, problems such as inadequate generation of microplants and slow microplant to field turnover are still encountered. Hence, commercial propagation and cultivar release of anthurium is hindered. To address current problems encountered in anthurium micropropagation, this thesis explored the use of RITA® bioreactors to accelerate anthurium shoot initiation and multiplication. The in vitro shoot production capacity of Anthurium andraeanum Hort. ‘New Pahoa Red’ under the RITA® bioreactor system and the conventional flask system were compared. The RITA® bioreactor system produced higher numbers of initiated shoots (3-4 fold) and increased proliferation rates by 1.6-2.6 fold compared to the conventional flask system. Culture conditions, namely immersion time, media volume and resting interval, for the RITA® bioreactor system were also optimized. A 5-minute immersion time, media volume of 20 mL/explant with a resting interval of 2 hours increased in vitro secondary shoot production and axillary bud mass volume. A comparative analysis of ten anthurium genotypes was done to assess variability of in vitro growth responses under the RITA® bioreactor system. Shannon-Weaver diversity indices revealed low to moderate diversity/variability for the in vitro responses. Through cluster analysis, five clusters were classified based on quantitative and qualitative parameters. Cross-referencing clusters with existing pedigrees revealed similarities within the lineages of the genotypes and that genotype exerts a greater influence over secondary shoot production compared to growth habit. The inclusion of RITA® bioreactors in micropropagation systems and assessment of genotype dependency will enhance microplant production and accelerate cultivar release of anthuriums. Along with pedigree records and historic data, comparative analysis of in vitro growth responses could provide a benchmark for protocol optimization. It could also help with the identification of genotypes that perform well under in vitro conditions which can be used to introgress in vitro culture suitability in cultivar development.