ABSTRACT 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.

Resumo O cultivo do lisianthus destaca-se na cadeia produtiva da floricultura como uma espécie destinada à produção de flores de corte e em vaso, cultivada em casa de vegetação empregando técnicas avançadas de produção. O objetivo do presente trabalho foi avaliar os pigmentos vegetais de diferentes cultivares de lisianthus sob diferentes telas foto seletivas. As cultivares Flare Deep Rose (rosa), Echo Blue BL (roxa) e Allemande White BI (branca) foram cultivadas com cobertura de filme de polietileno difusor de luz e telas foto seletivas das colorações, azul e vermelha, com capacidade de sombreamento de 30%, além do tratamento controle, sem o uso de tela. Os resultados obtidos demonstraram maiores valores de clorofila b e total em tela foto seletiva vermelha, independentemente do cultivar. Na colorimetria das folhas, a tonalidade de verde mais intensa foi do cultivar Echo Blue BL. Por outro lado, o controle apresentou tonalidade mais intensa, não ocorrendo diferença significativa na intensidade do verde das folhas nas telas azul e vermelha. No telado vermelho, as pétalas da variedade Echo Blue BL apresentaram tonalidade de azul mais intensa, porém menores teores de antocianina. Os resultados indicam que o uso de telas foto seletivas na cultura de lisianthus altera o teor dos pigmentos estudados, em intensidade variável, dependendo do cultivar.

Abstract The lisianthus culture is demanded to produce cut flowers and pot vases, grown in a greenhouse using advanced techniques. The present study aimed to evaluate the pigments of different lisianthus cultivars in different photoselective shade nets. The cultivars Flare Deep Rose (pink), Echo Blue BL (purple) and Allemande White BI (white) were cultivated under light-diffusing polyethylene film cover and blue and red color photoselective nets with a shading capacity of 30%, in addition to the control treatment, without the use of the net. The results showed higher values of chlorophyll b and total in the red photoselective net, independent of the cultivar. Leaf colorimetry showed the most intense shade of green was from the cultivar Echo Blue BL. On the other hand, the control showed more intensity, with no significant difference in the leaf green intensity on the blue and red shade nets. In the petals, the cultivar Echo Blue BL showed a more intense blue shade in the red net, however low grade of anthocyanin than in the blue one. In the anthocyanin pigment, this cultivar had lower levels in the treatment of the red net. The results indicate that the use of photoselective shade nets in the culture of lisianthus changes the content of the pigments studied, in varying intensity, depending on the cultivar.