Fig. 1
Spike branching in diploid T. monococcum wheat. a, Illustration of the spike structure in the T. monococcum KT 3–24 (middle), harboring short branch-like structures (right) with supernumerary spikelets (indicated with blue arrows) and T. sinskajae PI 418587 (a WT-spike) (left). b, Schematic representation of the WFZP gene structure and the mutation identified. The light red box indicates the AP2/ERF domain. c, A partial 2Am molecular-generic map showing collocation of bh m, wfzp-A.2 and SSR-WFZP-A (ssrCS248B13–1 from Dobrovolskaya et al. [31]) on 2Am. Genetic distances are given in cM. d-j, Scanning electron microscopy images of KT 3–24 (bh m) and PI 418587 (WT) inflorescences at various developmental stages. d and e, Spikelet differentiation stage in the wild type (d) and bh m (e). F, Early floret differentiation stages when the spikelet meristem produces the FM in the wild type. g and h, Differentiation of secondary AxMs (indicated by asterisks) in the bh m mutant. h and j. The development of glumes (gl*) and FM*s by secondary AxMs in the bh m mutant. i, Floret differentiation stage showing differentiated floral organs in the WT-inflorescence. j, The development of ectopic spikelets in bh m. Bars = 100 μm. f, floret with floret organ primordia; fm, floret meristem; gl, glume; im, inflorescence meristem; l, lemma, sm, spikelet meristem; sm*, spikelet meristem of an ectopic spikelet