Fig. 1: Phenotypic characterization of inflorescence from tetraploid Wa-1 plants.

a–c Representative images of inflorescence types observed in the tetraploid (4x) Wa-1 population. a An inflorescence with super fertile multilocular siliques. b An inflorescence consisting only of curly pistils/siliques. c An inflorescence containing a random distribution of both multilocular and curly siliques. d Representative images of a Wa-1 normal silique arising from a bicarpellary WT pistil, a multilocular silique originating from a pistil with supernumerary carpel and a developmentally arrested curly pistil/silique. e–g A transverse section of a bicarpellary (e), tricarpellary (f), and a tetracarpellary (g) silique from Wa-1 plants. Arrowheads indicate replum. h, i Matured siliques from normal (h) and multilocular (i) Wa-1 split open to reveal its anatomy. Normal silique shows two placental arrays of seeds attached to either replum surrounded by two carpel valves (h). Multilocular silique shows four placental arrays of seeds on a multiple repla surrounded by four carpel valves (i). j Replum-septum skeletons of individual siliques post dehiscence depicting multiple irregular replums and abnormal fusion of septum in multilocular siliques (numbered 1, 2, 3) to the normal one having two parallel replums interconnected by a continuous membranous septum (numbered 4). k Box and whisker plot showing seed count/silique from random (n = 20) normal, multilocular and curly siliques, respectively. The seed set is statistically significant (p < 0.0001, Kruskal–Wallis test, 2df, α = 0.05), Dunn’s posthoc test for three pairwise comparisons are also statistically significant with p values as indicated. l A partially fused (arrowhead) tetracarpellary pistil posing a folded fingers like phenotype. m Unfused tetracarpellary pistil showcasing two partially fused bicarpellary pistils embracing each other. n Congenital fusion of stamen to improperly fused carpel. o A stamen (arrowhead) arising from the carpel tissues. p Proliferative mass of apical stigmatic like tissues seen on the median portion of the carpel. q Sepal-like leafy outgrowth in carpels. r A flower originating from carpel tissues. s WT flower from the diploid Col-0 accession. t A superwoman flower from the tetraploid Wa-1 accession. u WT flower shown in s dissected to reveal six stamens and a bicarpellary pistil(arrowhead). v The superwoman flower shown in t dissected to reveal six stamens and a tetracarpellary pistil (arrowhead). w Wa-1 ploidy series consisting of haploid (x), diploid (2x), triploid (3x), and tetraploid (4x) individuals showing Wa-superwoman phenotypes (red arrowhead—multilocular siliques, blue arrows—curly siliques). Scale bar: a–c = 1 cm, d–t = 1 mm.