Figure 1 Construction of F2 population between marigold S5 and JH, and segregation of ray corolla traits in the F2 population Pi: Pistil; St: Stamen. Bars=1 cm

Figure 2 Stereomicroscope and scanning electron microscope observation of floral organs of marigold S5 and JH at full blooming stage

Figure 3 The observation of transverse semi-thin sections in four whorls floral organs of marigold S5 and JH at full blooming stage Vb: Vascular bundles; Bu-like: Bubble-like cells; UE: Upper epidermis; ML: Middle layer; LE: Lower epidermis; Po: Pollen grains; Pa: Papilla cells. Bars=25 μm

Figure 4 Stereomicroscope observation of floral buds of marigold S5 (A-E) and JH (F-J) at different developmental stages (A), (F) 1 mm buds; (B), (G) 1.5 mm buds; (C), (H) 2 mm buds; (D), (I) 3 mm buds; (E), (J) 4 mm buds. IP: Inflorescence primordium; RFP: Ray floret primordium; DFP: Disc floret primordium; Disc-like: Disc-like floret corolla; Ray-like: Ray-like floret corolla. Bars=200 μm

Figure 5 The transverse section of paraffin sections of floral buds of marigold S5 (A-F) and JH (G-L) at different developmental stages (A), (G) 0.5 mm buds; (B), (H) 1 mm buds; (C), (I) 1.5 mm buds; (D), (J) 2 mm buds; (E), (K) 3 mm buds; (F), (L) 4 mm buds. IP: Inflorescence primordium; RFP: Ray floret primordium; DFP: Disc floret primordium; PaP: Pappus primordium; CoRP: Corolla primordium of ray floret; CoDP: Corolla primordium of disc floret; StP: Stamen primordium; PiP: Pistil primordium; Pa: Pappus; Co: Corolla; St: Stamen; Pi: Pistil. Bars=100 μm

Figure 6 Scatter diagram of homologous gene alignment between marigold transcriptome and sunflower genome based on the results of BSR-seq analysis Grey dots: Locations of homologous genes in marigold mapped to sunflower; Colorful dots: Unigenes in marigold with ΔSNP index≥0.3

Figure 7 PCR amplification results of 37003-SCAR marker (A) and 34032-CAPS marker (B) in parents and F2 population M: 2 000 bp marker; 1-10: Individuals of F2 with ray floret without lobes and stamens; 11-20: Individuals of F2 that have ray florets with five-lobed and stamens, of which 11-15 are homozygotes and 16-20 are heterozygotes.