Postharvest conservation of lisianthus inflorescences with bioregulators

Cut flowers are known for their beauty and variety of colors and shapes. However, they quickly lose their commercial value after harvest due to the intensity of physiological processes that result in senescence. This work aimed to evaluate the effects of bioregulators on the postharvest longevity of lisianthus flowers (Eustoma grandiflorum cv. Flare Deep Rose) by applying a pulsing solution for 24 hours. The treatments consisted of 70 μM of 6-benzylaminopurine (BAP); 5 μM of gibberellic acid (GA3); 10 μM of abscisic acid (ABA); and deionized water as control. Turgidity, floral development, total and reducing sugar contents, respiration rate, colorimetry, anthocyanin contents, phenolic compound contents, and phenylalanine ammonia-lyase (PAL) enzyme activity were evaluated. BAP resulted in higher PAL enzyme activity and greater accumulation of anthocyanins when compared to the other treatments. The treatment GA3 resulted in the highest increase in respiration rate during storage, causing a larger number of inflorescences with wilting and senescence symptoms, reducing postharvest quality. The treatment ABA resulted in greater turgidity and floral opening, delayed senescence, and maintained respiration rate due to the greater total sugar contents on the fourth and 12th days. The application of ABA contributes to the maintenance of inflorescence quality for lisianthus at postharvest, but it reduces anthocyanin contents, providing petals with lighter colors.