Relação do cálcio e do silício na produção de matéria seca e na qualidade de plantas de repolho e de rúcula
Carregando...
Arquivos
Data
2021-02-17
Autores
da Silva, Dalila Lopes
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Uma alternativa para atenuar os efeitos dos danos causados pela deficiência nutricional de cálcio (Ca) em plantas de repolho e de rúcula é o fornecimento do silício (Si), tendo em vista seu potencial na redução de desordens nutricionais, porém os mecanismos envolvidos são desconhecidos nestas hortaliças. Objetivou-se verificar se o fornecimento de Si em solução nutritiva mitigaria os efeitos da deficiência de cálcio e se potencializa os efeitos na suficiência deste nutriente, ao aumentar compostos de defesa não enzimáticos e a qualidade pós-colheita nas plantas de repolho e de rúcula. Para isto, foram executados dois experimentos distintos, o primeiro com a cultura do repolho e o segundo com a cultura da rúcula, ambos em esquema fatorial 2x2, sendo deficiência (0,75 mM) e suficiência de Ca (5 mM) combinados na ausência e na presença de silício (2,5 mM) na solução nutritiva, dispostos em blocos casualizados com cinco e sete repetições, respectivamente. A fonte de Si utilizada foi silicato de sódio e potássio estabilizado com sorbitol, realizando-se o balanceamento do K na solução nutritiva entre os tratamentos. Em ambos os experimentos, a deficiência de Ca aumentou o estresse oxidativo a partir do aumento do índice de extravasamento de eletrólitos celulares e a partir do baixo teor de composto antioxidante, promovendo a diminuição da produção de matéria seca e da qualidade após o corte das folhas. Ao adicionar Si à solução de cultivo, ocorreu o aumento do conteúdo de ácido ascórbico (AsA) e da firmeza dos tecidos, nas plantas de repolho e de rúcula, fenóis totais, carotenoides, a eficiência quântica do fotossistema II em rúcula, diminuindo o índice de extravasamento celular nas duas culturas, promovendo maior qualidade destas hortaliças pós-colheita.
An alternative to mitigate the effects of the damages caused by the nutritional deficiency of calcium (Ca) in cabbage and rocket’s plants is the supply of silicon (Si), considering its potential to reduce nutritional disorders, however the mechanisms involved are unknown in these vegetables. The objectives were to verify if supplying Si in a nutrient solution would mitigate the effects of calcium deficiency and enhance the effects on the sufficiency of this nutrient, by increasing non-enzymatic defense compounds and post-harvest quality in cabbage and rocket’s plants. For this, two different experiments were carried out, the first with the cabbage culture and the second with the rocket culture, both in a 2x2 factorial scheme, being deficiency (0.75 mM) and Ca sufficiency (5 mM) combined in the absence and presence of silicon (2.5 mM) in the nutrient solution, arranged in randomized blocks with five and seven repetitions, respectively. The sources of Si used were sodium silicate and potassium stabilized with sorbitol, the K balance in the nutrient solution was carried out between treatments. In both experiments, Ca deficiency increased oxidative stress by increasing the rate of cell electrolyte leakage and by the low content of antioxidant compound, promoting a decrease in dry matter production and quality after leaf cutting. When adding Si to the culture solution, there was an increase in the content of ascorbic acid (AsA) and the firmness of the tissue, in cabbage and rocket plants, total phenols, carotenoids, the quantum efficiency of photosystem II in rocket, decreasing the index cell extravasation in both cultures, promoting higher quality of these post-harvest vegetables.
An alternative to mitigate the effects of the damages caused by the nutritional deficiency of calcium (Ca) in cabbage and rocket’s plants is the supply of silicon (Si), considering its potential to reduce nutritional disorders, however the mechanisms involved are unknown in these vegetables. The objectives were to verify if supplying Si in a nutrient solution would mitigate the effects of calcium deficiency and enhance the effects on the sufficiency of this nutrient, by increasing non-enzymatic defense compounds and post-harvest quality in cabbage and rocket’s plants. For this, two different experiments were carried out, the first with the cabbage culture and the second with the rocket culture, both in a 2x2 factorial scheme, being deficiency (0.75 mM) and Ca sufficiency (5 mM) combined in the absence and presence of silicon (2.5 mM) in the nutrient solution, arranged in randomized blocks with five and seven repetitions, respectively. The sources of Si used were sodium silicate and potassium stabilized with sorbitol, the K balance in the nutrient solution was carried out between treatments. In both experiments, Ca deficiency increased oxidative stress by increasing the rate of cell electrolyte leakage and by the low content of antioxidant compound, promoting a decrease in dry matter production and quality after leaf cutting. When adding Si to the culture solution, there was an increase in the content of ascorbic acid (AsA) and the firmness of the tissue, in cabbage and rocket plants, total phenols, carotenoids, the quantum efficiency of photosystem II in rocket, decreasing the index cell extravasation in both cultures, promoting higher quality of these post-harvest vegetables.
Descrição
Palavras-chave
Brassicas, Brassica oleracea var. capitata, Eruca sativa Miller, Deficiência cálcica, Silicato