Combined morphological, physiological and metabolomic analysis of floral thermotolerance in dancing lady orchid.

Dancing lady orchids (Oncidium and related germplasm) show multifactorial floral thermotolerance, with T50 negatively linked to flower area and fresh mass and Tp linked to longevity.

• Why it matters: Rising heat threatens floral organs, yet mechanisms are poorly studied in orchids with high floral resource allocation, limiting germplasm conservation and breeding guidance.
• What they did: The study quantified thermotolerance using cell membrane thermostability (T50) and perianth cuticular phase transition temperature (Tp), then correlated them with floral allocation, hydraulic traits, structural heterogeneity, and volatile metabolite shifts under sequential high-temperature gradients.
• The result: T50 and Tp were not significantly correlated; T50 was weakly constrained by phylogeny while Tp showed no phylogenetic dependence, and volatile compounds with low water solubility followed a unimodal accumulation pattern under elevated temperatures.