Quantitative PCR analysis of floral organ identity genes at different floral organs in single and double flower phenotype carnations. DcaAP1 (A) had higher expression in the sepal than that in petal, stamen, and carpel. DcaAP2 (B) expressed in all floral organs stably. DcaPI (C) and DcaAP3 (D) had higher expression in the second and third whorls than that in the first and fourth whorls. DcaSEP1 (E) and DcaSEP3 (F) expressed relatively smoothly in all floral organs between single and double flower phenotype carnations. The expression of DcaAP1 (A), DcaAP2 (B), DcaPI (C), DcaAP3 (D), DcaSEP1 (E), and DcaSEP3 (F) had no significant difference in sepal, petal, stamen and carpel between two flower phenotype carnations. Student’s t-test was used to determine significant differences in expression.