Caracterização de Fusarium solani f. sp. piperis, produção de fitotoxina e incidência da fusariose no norte de Minas Gerais

Abstract

A podridão das raízes causada por Fusarium solani f. sp. piperis é uma das principais doenças da pimenteira-do-reino no norte de Minas Gerais. Os objetivos deste trabalho foram quantificar a incidência da doença nas principais áreas produtoras do norte do estado de Minas Gerais, identificar o agente causal da fusariose, testar a patogenicidade dos isolados e avaliar a ação de filtrados de F. solani f. sp. piperis sobre folhas destacadas de pimenteira-do-reino e sobre Trichoderma asperellum. Avaliou-se a incidência da fusariose em 1.000 ou 500 plantas de forma arbitrária, em percurso em zigue-zague. A reação de pimentado-reino 'Cingapura' foi avaliada em relação a dois filtrados fúngicos (FPC1 e FPB2), e o isolado FPB2 foi empregado para avaliar a reação das cultivares Cingapura e Guajarina. Outro experimento foi realizado para estudar a influência das diluições do filtrado FPB2 em folhas da cultivar Cingapura. ABSTRACTRoot rot caused by Fusarium solani f. sp. piperis is one of the major diseases affecting black pepper in the north of Minas Gerais State, Brazil. The aims of this study were to quantify the disease incidence in the main black pepper growing areas of Northern Minas Gerais State, to identify the causal agent of root rot, to test the pathogenicity of isolates and to evaluate the effect of Fusarium solani f. sp. piperis filtrates on both detached leaves from black pepper and Trichoderma asperellum. The incidence of root rot was randomly evaluated in 1,000 or 500 plants at zigzag. The reaction of black pepper cv. Cingapura was evaluated against two fungal filtrates (FPC1 and FPB2), and the isolate FPB2 was used to evaluate the reaction of cultivars Cingapura and Guajarina. Another experiment was performed to study the influence of FPB2 filtrate dilutions on the leaves of cultivar Cingapura. To evaluate the effect of toxins of the filtrates on Rocha, F.S.; Ferreira, G.H.S.; Silva, T.C.S.R.; Amaral, F.L.; Muniz, M.F.S.; Pereira, E.A. Characterization of Fusarium solani f. sp. piperis, phytotoxin production and disease incidence in Northern Minas Gerais, Brazil. Summa Phytopathologica, v.42, n.1, p.67-72, 2016. the Mycelial Growth Index (MGI) of T. asperellum, a trial was carried out with different concentrations and two filtrates. The disease incidence in the sampled areas was 31.5 to 100% for the municipalities of Bocaiúva and Montes Claros, respectively. Based on the sexual compatibility test, the isolates were identified as F. solani f. sp. piperis. Nine isolates were pathogenic when inoculated in seedlings of black pepper at four-month development. FPB2 filtrate produced the greatest severity (average of 93.6% necrotic leaf area), compared to FPC1 isolate (5.8%). The cultivar Cingapura was more sensitive to the action of the filtrate. The FPB2 filtrate dilution reduced the percentage of diseased leaf area. Furthermore, the increase in the concentrations of FPC1 filtrate contributed to increase the MGI of T. asperellum, whereas FPB2 filtrate showed opposite effect, reducing the MGI of this antagoni...

Aggressiveness of Fusarium oxysporum and Fusarium solani isolates to yerba-mate and production of extracellular enzymes

“…These results affirm the pathogen potential to cause damage to the host species. Reinforcing the results obtained in the present study, Rocha et al (24) observed, 21 days after inoculation, the dryness and reduction of the root system of black pepper (Piper nigrum L.) in addition to the incidence of 100% fusariosis caused by F. solani f. sp. piperis.…”

Trichoderma: biological control efficiency and perspectives for the Brazilian Midwest states and Tocantins

“…The soil complexity and the F. solani genetic variability make its resulting disease difficult to control, thus continuing on the ground for several seasons (Milanesi et al, 2013). The species cause plant to display yellowish leaves, vascular system discoloration, and plant wilt (Rocha et al, 2016). According to Desjardins (2006), one of its strategies is producing a wide variety of toxic and bioactive secondary metabolites for host colonization.…”

Thymol as an Interesting Building Block for Promising Fungicides against Fusarium solani

“…Vietnam stands out as the largest producer and exporter, followed by India, Brazil, and Indonesia. Numerous diseases that are caused by viruses, fungi, algae, and nematodes affect the black pepper crop . However, fungal diseases present the greater impact in black pepper crop losses, specifically the root rot ( Nectria hematococca Berk & Br.…”