Ethylene-induced variation in anthocyanin composition associated with postharvest performance in Vanda flowers

• The postharvest performance of Vand a flowers varies with season and cultivar, with summer-harvested flowers showing higher ethylene sensitivity and shorter vase life. • Postharvest flower color changes are determined by both anthocyanin level and compositional shifts. • Ethylene-induced rapid bleaching in Pachara Delight ‘Pink’ is linked to selective cleavage of high-molecular-weight polyacylated cyanidin derivatives, accompanied by increases in free sinapic and ferulic acids. Ethylene plays a critical role in the postharvest performance of cut flowers. However, the effects of ethylene on cut flower performance during the postharvest stage have rarely been linked to changes in anthocyanin composition. In this study, we investigated the effects of ethylene on vase life across seasons and on anthocyanin composition in cut flowers from three Vanda cultivars. Treatment with 1 μL L –1 ethylene shortened vase life and accelerated fresh weight decline in flowers from all cultivars, especially those harvested in summer. Furthermore, ethylene-induced, cultivar-specific postharvest color performances were found to be associated with differences in anthocyanin composition. Pachara Delight ‘Blue’, which senesced with wilting and shrinking but maintained stable coloration, showed a largely unchanged anthocyanin composition, with a minimal and uniform decline across most delphinidin derivatives. Kulwadee Fragrance ‘Black’ exhibited accelerated wilting and notable color changes, showing a transition in the composition of cyanidin derivatives. Pachara Delight ‘Pink’, which exhibited rapid bleaching followed by wilting and shrinking, showed a significant depletion in high molecular-weight cyanidin derivatives ( m/z ≥ 1125), identified as polyacylated forms, and was accompanied by increased levels of sinapic acid and ferulic acid. Our findings suggest that ethylene-induced color variation in Vanda is associated with distinct shifts in anthocyanin composition, and that the rapid bleaching in Pachara Delight ‘Pink’ may involve selective depletion of polyacylated anthocyanins via an ethylene-dependent de-acylation process.