Supplementary Fig.1 Comparison of early flower mutant recovered from irradiated PLBs at 10 Gy dose with the flower of ‘Emma White’ mother plant

Early flowering mutant 10/46 (b) which, flowered within 9.6 months of ex-vitro growth, was observed with deformity in the floral structure, as the dorsal and the lateral sepals fused with no petals. The lip of the mutant flower appeared slightly rounded with wavy edges and longer side lobes compared to the flower of mother plant (a) of Dendrobium ‘Emma White’ with two petals (P), one dorsal sepal (DS), two lateral sepals (LS), lip (L), and column (C). The mutant plant was numbered according to the radiation dose followed by plant number, i.e., 10 Gy, followed by plant number 46 (10/46).

早花突变体10/46（b）在离体移栽后生长（ex-vitro growth）9.6个月内即可开花，其花部结构存在畸形：背萼片与侧萼片合生，且无花瓣形成。该突变体源自石斛‘艾玛白’（Dendrobium ‘Emma White’）的诱变群体，其母株（a）为该品种的正常植株，该正常植株的花具有2枚花瓣（Petal, P）、1枚背萼片（Dorsal sepal, DS）、2枚侧萼片（Lateral sepal, LS）、1枚唇瓣（Lip, L）和合蕊柱（Column, C）；相较于该母株的正常花，突变体花的唇瓣略呈圆形，边缘呈波浪状，侧裂片更长。该突变体植株的编号依据辐射剂量与植株序号制定：先标注辐射剂量10 Gy，再标注植株序号46，故编号为10/46。