The leaf surface micromorphology and the size of the stomatal complex of hybrids in the eighth seed generation from the crossing of ×Trititrigia cziczinii × Elymus farctus (f11814) on the wheat-like wheat-wheatgrass hybrid w107 were investigated by performing scanning electron microscopy of frozen samples (cryoSEM). The micromorphological characteristics of the paternal plants (w107) were dominant in the hybrid leaves. Costal long cells with silicified wavy walls, characteristic of w107 but absent in the mother plants f11814 and E. farctus, were observed in all hybrid samples examined. Conversely, shield-shaped prickles, a characteristic feature of E. farctus, were retained only in some hybrids. In addition, the maternal feature of Ω-shaped junctions of long epidermal cells in the intercostal zone was completely absent in hybrids. Quantitative parameters of the stomatal apparatus showed a weak correlation with micromorphological markers. Stomatal density on the adaxial side was inversely correlated with stomatal size, while variation in these parameters on the abaxial side occurred independently. The prevalence of paternal micromorphological traits in the hybrids seems to be a consequence of the elimination of genetic material from E. farctus, analogous to the loss of chromosomes from wild species observed in other distant crosses.

This study used cryoSEM to analyze the seasonal stability of leaf surface micromorphology in cereal hybrids derived from crossing maternal ×Trititrigia cziczinii × Thinopyrum junceum lines with paternal wheat–wheatgrass hybrids. Over two growing seasons, relatively rare traits showed high stability, while most traits exhibiting initial diversity demonstrated seasonal variability. Paternal traits (hairs, prickles, elongated silica cells) predominated in hybrids, and hybrid diversity correlated significantly with paternal, but not maternal, line diversity. In 2025, a significant decrease in some paternally specific traits and an increase in rounded silica cells were observed compared to 2024. Coordinated dynamics were revealed: variations in maternal traits correlated positively with each other and negatively with some paternal traits. While certain micromorphological features exhibited relative stability, employing such traits for taxonomic purposes necessitates caution and a thorough understanding of their inherent variability ranges.