Quality evaluation and aroma biosynthesis mechanism of seven strawberry varieties grown in solar greenhouse.

Seven strawberry cultivars from solar greenhouses were used to analyze fruit quality, physiology and aroma profiles. Results showed 'Monterey' had the highest hardness (0.56 kg·cm-2) and titratable acid content (0.99%). 'ZhangJi' had the highest soluble total sugar content (5.92%). 'Snow Hare' had the highest fructose content (45.35 mg·g-1). 114 aroma substances in 7 categories were detected, esters as the main component. 'MiaoXiang No.7' had the highest total aroma content and total aroma value (357.86), and the contents of key aroma substances. 'Monterey' contained unique esters and ketones. A comprehensive evaluation model for the quality of strawberry fruits in protected facilities was established through principal component analysis: F = 0.2984F₁ + 0.2436F₂ + 0.1848F₃ + 0.1518F₄. 'MiaoXiang No.7' performed best in overall quality and aroma intensity. Further analysis showed that LOX2 1, ACOX1, AIM1, FvPAL1-2 and HMGR1-like were highly expressed in 'MiaoXiang No.7', synergistically enhancing the biosynthesis of esters, aldehydes and terpene.