Mechanical strength and anatomical structure of the peduncles of rose (Rosa x hybrida) flowers

The anatomical differences between the strong flower peduncles of the rose cv. Mercedes and the weak peduncles of cv. Nubia were investigated. More supporting cells with thicker cell walls were found in the xylem elements and phloem fibers of the cv. Mercedes peduncles than in those of cv. Nubia. Secondary increment was observed in the proximal zone of the peduncles of both cultivars. A complete ring of secondary thickening developed in the peduncles of cv. Mercedes, whereas in cv. Nubia the ring was incomplete due to the lack of interfascicular cambium. These differences were correlated with the postharvest tendency to peduncle bending of these two cultivars.