Cultivation protocol using a coir-based substrate modulates the concentration of bioactive compounds and the antioxidant activity of Passiflora alata Curtis seedlings

• Published in: Ciência e agrotecnologia 2023, Vol.47
• Main Authors: Muniz, Brena Coutinho, Falcão, Eduarda Lins, Bastos Filho, Carmelo José Albanez, Silva, Fábio Sérgio Barbosa da
• Format: Article
• Language: English
• Subjects: AGRICULTURE, MULTIDISCIPLINARY; organic residue; Plant growth; secondary compounds; sweet passion fruit
• ISSN: 1413-7054; 1981-1829; 1981-1829
• DOI: 10.1590/1413-7054202347014922

ABSTRACT The use of coconut coir dust is a low-cost cultivation practice. Thus, this study aimed to determine the effect of coconut coir dust proportion on foliar secondary metabolite biosynthesis and growth of Passiflora alata Curtis (sweet passion fruit). This Passiflora species possess pharmaceutical relevance and the use of organic-based substrates may promote the production of bioactive compounds in the phytomass. An experiment in a greenhouse was set up with three proportions of coir dust mixed with a commercial substrate for seedlings (CSS) (peat-based) (S1= 1:1:1, CSS: sand: coconut coir dust; S2= 1.5:1.5:1, CSS: sand: coconut coir dust and S3= 1:1, sand: CSS) in seven replicates. After 68 days, growth parameters were measured (height, leaf area, number of leaves, stem diameter, and dry matter), and the harvested leaves were used to prepare ethanolic extracts. The total antioxidant activity and production of phenolics, flavonoids, proanthocyanidins, and saponins were assessed. Unexpectedly, the coir dust supply did not favor the growth and production of secondary metabolites, as the best results were observed in plants grown in S3. Moreover, S3 is efficient in optimizing the growth, metabolite content, and antioxidant capacity of P. alata foliar extracts dispensing coir dust supplementation in the substrate. Therefore, adding coir to CSS is not recommended to enhance the production of secondary metabolites and the growth of P. alata seedlings. RESUMO O uso de pó de coco é uma prática de cultivo de baixo custo. Por isso, o objetivo desta pesquisa foi definir o efeito da proporção de pó de coco para aumentar a biossíntese de metabólitos secundários foliares e o crescimento de Passiflora alata Curtis (maracujazeiro-doce). Essa Passiflora possui relevância farmacêutica e o uso de substratos orgânicos pode promover o aumento da produção de compostos bioativos na fitomassa. Um experimento foi conduzido com três proporções de pó de coco em substrato comercial para mudas (SCM) (à base de turfa) (S1= 1:1, SCM: areia: pó de coco; S2= 1,5 :1,5:1 , SCM: areia: pó de coco e S3= 1:1, areia: SCM), em sete repetições. Após 68 dias, parâmetros de crescimento foram avaliados (altura, área foliar, número de folhas, diâmetro do caule e matéria seca) e as folhas utilizadas para preparar os extratos etanólicos. Com esses extratos, foi avaliada a atividade antioxidante total e a produção de compostos fenólicos, flavonoides, proantocianidinas e saponinas. A adição de pó d