1. Suppl. Fig. S1. a) Potato somatic hybrids between C-13 and S. cardiophyllum confirmed with possessing parental bands by SSR marker STM0031, M = 50 bp DNA ladder. b) Chloroplast-type markers ALC1/ALC3 showed cytoplasm types (W/α and W/γ) of somatic hybrids based on 622 bp amplification (Lössl et al. (2000), M = 1 kb DNA ladder. P 1 = C-13, P 2 = S. cardiophyllum, P 1 +P 2 = pooled parental DNA; somatic hybrids #1-4 = Crd-6, Crd-10, Crd-16 and Crd-23, respectively. bp 200 160 M P1 P2 P1+P2 1 2 3 4 a d bp 815 622 M P1 P2 P1+P2 1 2 3 4 b

2. Suppl. Fig. S2. AFLP primer pairs combination (EcoRIACA+MseICTG) confirmed hybridity of the potato somatic hybrids C-13 (+) S. cardiophyllum possessing parental bands. (a) C-13 (215 bp), (b) S. cardiophyllum (162 bp), and (c) somatic hybrid (162 and 215 bp) analyzed on the “3500 Genetic Analyzer” (ABI). Note: because of less peak intensity of 215 bp of somatic hybrid (c image panel) Y-axis scale is reduced to 800 to visualize the peak. 215 bp 162 bp 215 bp 162 bp a b c 60 100140 180 220260 2000 1800 1600 1400 1200 1000 800 600 400 200 0 60 100140 180 220260 2000 1800 1600 1400 1200 1000 800 600 400 200 0 800 700 600 500 400 300 200 100 0 60 100140 180 220260

3. Suppl. Fig. S3. Ploidy estimation of somatic hybrids and their parents by flow cytometry analysis a) tetraploid common potato cv. Kufri Jyoti (4x), and b) tetraploid somatic hybrid clone Crd-6 (4x). Kufri Jyoti (4x) Somatic hybrid (4x) a 80 60 40 20 0 Counts FL4 DAPI 0 200 400 600 80 60 40 20 0 Counts FL4 DAPI 0 200 400 600 b

4. Suppl. Fig. S4. Potato somatic hybrids of C-13 (+) S. cardiophyllum: a) pollen viability and b) berry formation of cross between Kufri Girdhari x somatic hybrid (Crd 23) a b