Respiration, Carbon Balance and Translocation of Dry Matter in the Corolla of Rose Flowers

The effects of import of dry matter from the leaves on respiration,metabolism of carbohydrates and development of the corolla werestudied in intact flowering rose shoots and compared with cutflowering shoots bearing either seven leaves on 45 cm stemsor two leaves on 30 cm stems. Over 4 days, corollas of two-leaf shoots imported and respiredless carbon than either the intact or the seven-leaf shootsand they developed more slowly. Starch levels in the corollaat the end of this time depended on the stage at which it wascut; more advanced flowers (stage 3–4) tended to losestarch whereas less advanced ones (stage 1–2) tended toaccumulate it. Total carbohydrate in the corolla was dependenton leaf number. Loss of d. wt of leaves indicated that they provided dry matterto the corollas even in cut shoots, and this observation wassupported by the recovery of ¹⁴C-leaf assimilate from corollas.The depletion of dry matter from leaves and the slight delayin corolla development of the two-leaf cut shoots suggest thata dynamic source-sink (leaves—corolla) relationship existsin the senescing cut rose as in the intact rose. Rosa sp, corolla, respiration, carbon balance, translocation