Genotypes producing oils with oleic acid >90% in any environment are demanded.

The sunflower isogenic lines were non-mutated (traditional) or mutated (Pervenets and NM1).

Plants were exposed to minimum night temperatures from 11.8 to 23.2 °C.

NM1 showed oleic acid percentages >91.3 and more stable concentrations than Pervenets.

Ultra-high oleic quality was obtained in NM1 independently of growing temperature conditions.