Fig. 1

Phenotypic traits of both PHYMS wheat and the corresponding fertile line, MF-1376. a-c The morphology of MF-1376 (left) and PHYMS (right) anthers at the (a) tetrad, (b) mononuclear and (c) trinuclear stage of development. d Callose deposition in MF-1376 anthers at the tetrad stage. e Callose deposition in PHYMS anthers at the tetrad stage. f-g Anther nuclei from both (f) MF-1376 and (g) PHYMS wheat were stained at the mononuclear stage with carbol fuchsin. h Pollen grains from a fertile plant stained with KI-I₂ solution. i Pollen grains from a male-sterile plant stained with KI-I₂ solution. j-m SEM analysis of the surface of trinuclear stage anthers from (j, l) MF-1376 and (k, m) PHYMS wheat. n-o SEM analysis of pollen grains from (n) MF-1376 and (o) PHYMS wheat. Bars = 2 mm in (a-c), 100 μm in (d-i), 50 μm in (j-k, n-o), and 1 μm in (l-m)