Background and aims - Variations in floral traits and floral structures influence mating systems. The flowers of Alcea rosea are protandrous and herkogamous, with style curvature at anthesis. Methods - We measured: (1) floral morphology, including style curvature, (2) stigma receptivity and pollen viability, (3) breeding system, and (4) outcrossing rate estimated by ISSR markers. Key results - Results indicate that when stigmas were in contact with anthers via style curvature, stigma receptivity and pollen viability was 89.7 and 42.33%, respectively, indicating the potential of delayed selfing. Delayed selfing in A. rosea did not provide obvious contribution to seed production, because there was no significant difference in seed set between intact and emasculated open flowers (P = 0.765). However, successful reproduction of 23.98% flowers in the absence of pollinators suggested that selfing provides reproductive assurance during a year, in which pollinators were limiting. The multilocus outcrossing rates in different populations varied from 0.972 to 0.981, with a mean of 0.977. Conclusion - Our data provide an empirical demonstration of a predominantly outcrossing species with potential delayed selfing when pollinators are absent or scarce.

ALCEA ROSEA; DELAYED SELFING; ISSR MARKERS; OUTCROSSING RATE; REPRODUCTIVE ASSURANCE; STYLE CURVATURE