Argylia radiata polyploidization, first approach for future plant breeding

P. Morales-Tapia, M. Gambardella, R. Barba-Gonzalez
Argylia radiata (L.) D. Don (Fam.: Bignoniaceae) is an herbaceous perennial plant, native from the North of Chile and part of “Flowering Desert”. This understudied species has potential as an ornamental crop because of its blue-green foliage and multiple floral stems with trumpet flowers. As first approach of the A. radiata breeding process, polyploidization trials were run. Two induction agents, oryzalin and nitrous oxide, were tested at in vitro level. Under sterile conditions, A. radiata microplants were put inside Eppendorf tubes with oryzalin solution. Two concentrations and two times of exposition were assayed: 0.01 mg L‑1 during 24 h (T1); 0.01 mg L‑1 during 48 h (T2); 0.05 mg L‑1 during 24 h (T3); 0.05 mg L‑1 during 48 h (T4). Regards to the experiments with nitrous oxide, microplants of A. radiata were put on sterile glass tubes and located inside a gas chamber. The nitrous oxide was injected at 5 atm during 24 h (T5) and 48 h (T6). For all treatments, five plants were used. After the induction essays, the plants were transferred to a free hormones medium during three weeks and the regenerated shoots were cut, leaving only one bulb explant‑1. This process was repeated twice. The new microplants, regenerated from those buds, were treated as independent lines (56 lines were obtained), and they were transferred to fresh medium every 12 weeks during 1 year. No plants from T3 and T4 were possible to regenerate. After that period, a small piece of tissue, from each line, was analyzed by flow cytometry, detecting 1 mixaploid (75% 2n and 25% 4n) from T2. This material could be used in the future to obtain a complete tetraploid plant by bud's isolation, to generate polyploid pollen or it can be used as part of a breeding program.
Morales-Tapia, P., Gambardella, M. and Barba-Gonzalez, R. (2020). Argylia radiata polyploidization, first approach for future plant breeding. Acta Hortic. 1288, 59-64
DOI: 10.17660/ActaHortic.2020.1288.8
Argylia, Bignoniaceae, ornamental, polyploidization, Chilean native plant

Acta Horticulturae