Biocontrole de Meloidogyne javanica por fungo micorrízico orquidoide (Waitea circinata) em tomateiro

• Autor(a) principal: Mendes, Bruno Leonardo
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• dARK ID: ark:/38995/0013000008n95
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/11542
• topic: Nematoide; Micorriza; Fungo antagonista; Nematoide das galhas; Nematode; Mycorrhiza; Antagonist fungus; Root-knot nematode; CIENCIAS AGRARIAS

Several phytopathogenic microorganisms attack the tomato crop, among them, root-knot nematode Meloidogyne javanica, that is virulent and generates losses for producers. The use of conventional synthetic nematicides generates negative effects on the environment and human health, since the residual effect of these products is high in soil and fruit. Therefore, it is interesting to insert sustainable control methods into integrated management of M. javanica, such as biological control. Orchid Mycorrhizal Fungi (OMF) Waitea circinata has antagonistic action against leaf blast in rice crop, wherefore, this study aimed to evaluate the potential of the OMF W. circinata in antagonism to the M. javanica. We evaluated the effect of concentrations 5 g, 10 g, 15 g, 20 g and 25 g mycelium/L water of the mycelial suspension of W. circinata on the mortality and hatching of second stage juveniles (J2). The parasitic capacity of the OMF mycelium also were evaluate. After pathogenicity tests of the OMF suspension and mycelium on tomato plants cv. Santa Cruz Kada, experiments were conducted in a greenhouse to evaluate the effect of the W. circinata suspension on the nematode reproductive factor (RF) and nematode population density (PD). Were also evaluated the effect of fungus suspension on agronomic characteristics such as shoot length (SL), root length (RL) and fresh root mass (FRM). The concentration of 25 g of mycelium/L of water guaranteed 60% mortality of J2 in relation to the control treatment and presented positive linear regression. The mycelial suspension reduced 86% hatching of J2 and the mycelium was able to parasitize the M. javanica eggs. RF and PD were adjusted for negative linear regression, the concentration of 25 g/L of water stood out reducing by 30% and 90% the RF and PD, respectively. The data of agronomic characters had the same response pattern and adjusted for quadratic linear regression. Principal component analysis (PCA) corroborated regressions data and explained 71.05% of variability, the component 1 and component 2 explain for 47.16% and 23.89%, respectively. This is the first report of an orchid mycorrhizal fungus as a nematode antagonist. Therefore, after promising results, we can conclude that Waitea circinata is a fungus that can be used in the integrated management of Meloidogyne javanica.