Addition of Aegilops geniculata 1Ug chromosome improves the dough rheological properties by changing the composition and micro-structure of gluten

•The composition and micro-structure of gluten in two wheat lines were analyzed.•A novel HMW-GS (NS) was identified in a CS-Ae. geniculata 1Ug disomic addition line.•The NS substituted Dx2 subunit with a higher proportion in total HMW-GS.•The NS promoted the accumulation of unextractable polymeric protein.•The NS was responsible for denser gluten micro-structure and stronger dough strength.