Fusarium graminearum is associated with diseases in seeds and seedlings, mainly in maize, and causes damage to crops and food production. We determined the chemical compositions of essential oils from Pogostemon cablin (Blanco) Benth and Baccharis dracunculifolia DC., and evaluated their antioxidant and antifungal activity against F. graminearum. The oils were applied to the fungus using disc diffusion technique at concentrations of 8.0, 4.0, 2.0 and 1.0 μL mL -1 . Fungistatic effects of P. cablin oil were detectable at 8.0 μL mL -1 , with 80.0% inhibition of fungal growth. This oil contains mono and sesquiterpenes that may be toxic to fungal cell structures. P. cablin oil also had antioxidant activity in free radical sequestration experiments, where as oil from B. dracunculifolia had limited effects. We conclude that essential oil from P. cablin has greater anti-phytopathogenic and antioxidant activity than that from B. dracunculifolia.
Alternaria solani, agente etiológico da pinta preta, é considerado um fitopatógeno de grande impacto econômico na cultura do tomate, gerando grandes prejuízos aos agricultores. O objetivo deste trabalho foi verificar o potencial antagonista por confronto direto, produção de voláteis e atividade antimicrobiana in vitro de filtrado de fungos sapróbios contra A. ABSTRACTAlternaria solani, the etiological agent of early blight, is considered a phytopathogen of great economic impact on tomato crop, causing great losses to farmers. The aim of this study was to assess the antagonistic potential for direct confrontation, the production of volatile compounds and the in vitro antimicrobial activity of saprobic fungal filtrate against A. solani. Thus, the phytopathogen A. solani was confronted with the saprobic fungi Volutella minima, Memnoniella echinata, M. levispora, Curvularia eragrostidis, C. inaequalis, Gonytrichum chlamydosporium, G. macrocladum, Pseudobotrytis terrestris, Pithomyces chartarum, Lappodochium lageniforme, Dictyochaeta simplex, Stachybotrys nephrosfora and S. globosa, to observe inhibition zone formation and aggressiveness of the fungi according to a score scale. The phytopathogen growth was also evaluated at the concentration of 20% to select the saprobe filtrate with antimicrobial activity. Subsequently, the Solino, A.J.S.; Oliveira, J.B.S.; Schwan-Estrada, K.R.F.; Marianna Santos Rodrigues Alencar, Ribeiro, L.M. Antagonistic potential and in vitro control of Alternaria solani by saprobic fungi. Summa Phytopathologica, v.43, n.3, p.199-204, 2017. selected saprobe filtrates were studied at the concentrations of 5; 10; 15 and 20%, evaluating the mycelial growth of A. solani. The saprobes L. lageniforme and G. macrocladum showed greater mycelial growth, compared to A. solani, at seven days after transferring the phytopathogen. At 15 days, only L. lageniforme contained the pathogen. In the direct confrontation test, the fungi L. lageniforme and G. macrocladum occupied a larger area on the Petri dish, in contrast to the pathogen. The fungal filtrates G. macrocladum, C. inaequalis, P. terretris, S. globosa and C. eragrostidis, at a concentration of 20%, promoted a reduction in the mycelial growth of A. solani by 34, 21, 19, 10 and 10%, respectively. Analyzing the effect of the filtrate concentrations on the mycelial growth of A. solani, dose-dependence was observed in all treatments, with maximum growth inhibition for filtrates of G. macrocladum, C. inaequalis, P. terretris, S. globosa and C. eragrostidis, respectively, at the concentration of 20%.Keywords: biological control, antimicrobial activity, plant pathogen.Os cultivos agrícolas estão sujeitos a diversas doenças causadas por uma ampla gama de fitopatógenos (12). As alternarioses são doenças fúngicas causadas pelas espécies do gênero Alternaria que estão amplamente distribuídas no mundo, infectando principalmente hortaliças (22). A pinta preta, causada por Alternaria solani, é considerada uma doença de grande importância econômica nas culturas d...
RESUMO Dentre as doenças fúngicas da videira, merece destaque a mancha-da-folha causada por Pseudocercospora vitis. As condições favoráveis ao desenvolvimento da mancha-da-folha ainda não foram totalmente determinadas. Sabe-se que a formação de conídios ocorre sob condições de alta umidade e são disseminados pela ação do vento, iniciando novas infecções. Para aumentar o conhecimento sobre a produção, germinação e infecção do patógeno foram realizados três experimentos. No primeiro experimento, avaliou-se a produção de esporos de P. vitis, nos meios de cultura: BDA (batata-ágar-dextrose); BDA+Leite de coco (5%); BDA+extrato de uva cv. Isabel (5%); ST (suco de tomate-carbonato de cálcio-ágar); ST+leite de coco (5%); ST+extrato de uva cv. Isabel (5%). Houve esporulação em todos os meios testados e diferentes períodos de incubação. No segundo experimento, verificou-se que a temperatura de 25 °C propiciou maior porcentagem de conídios germinados e que houve maior germinação na ausência de luz. No terceiro experimento observou-se que a temperatura de 20 °C propiciou maior severidade da mancha-da-folha em mudas de videiras, após 48 horas de incubação no escuro.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.