ABA synthesis inhibitor inducing flowering of dormant peony without bud abortion

Y.H. Rhie, S.Y. Lee, K.S. Kim
Herbaceous peony is a common perennial plant that is used as a garden or medicinal plant in temperate regions and is commercially grown as a cut flower. Because the natural flowering period is from May to June, various methods have been developed to extend the flowering period. In our previous study, peonies were forced under greenhouse conditions after prolonged exposure to cold temperatures. We also investigated the effects of gibberellin (GA3) to break the dormancy of peonies. All uncooled peonies treated with GA3 sprouted but failed to flower due to shoot blind and flower bud abortion. Therefore, the purpose of this study was to investigate the effects of ABA biosynthesis inhibitors or additional GA treatments on uncooled peonies, so that they could be forced without causing blasting or bud abortion. Uncooled plants received 0 (control), 100, or 500 mg L‑1 (250 mL plant‑1) GA3 as a soil drench, were drenched 100 mg L‑1 GA3 + 100 mg L‑1 fluridone (FLU: ABA synthesis inhibitor) or sprayed with 10 mL of 100 mg L‑1 GA3 every two weeks following the drenching with 100 mg L‑1 GA3 in the glasshouse for forcing. The control plants failed to emerge for 5 months, so there were no buds or flowers. When uncooled plants were treated with GA or FLU, shoots appeared within 10 days. However, the shoot blasting was observed in 85 or 90% of those treated with 100 or 500 mg L‑1 GA3, respectively. The shoot blasting percentage decreased to 0 or 20% by GA3+FLU or additional GA3 spray treatments, respectively. Moreover, plants reached 80 or 50% flowering without flower bud abortion with GA3+FLU or additional GA3 spray treatments, respectively. However, chlorosis appeared on the leaves when treated with GA+FLU because FLU might block the production of carotenoids.
Rhie, Y.H., Lee, S.Y. and Kim, K.S. (2020). ABA synthesis inhibitor inducing flowering of dormant peony without bud abortion. Acta Hortic. 1291, 97-102
DOI: 10.17660/ActaHortic.2020.1291.12
abscisic acid, blasting, forcing, gibberellin, Paeonia lactiflora

Acta Horticulturae