Morphological and Molecular Characterization of Fusarium Spp. Pathogenic to Ilex Paraguariensis

Abstract

MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF Fusarium spp. PATHOGENIC TO Ilex Paraguariensis MEZZOMO, R.; ROLIM, J. M.; POLETTO, T.; ROSENTHAL, V. C.; SAVIAN, L. G.; REINIGER, L. R. S.; MUNIZ , M. F. B.Morphological and molecular characterization of Fusarium spp. pathogenic to Ilex Paraguariensis. CERNE, v. 24, n. 3, p. 209-218, 2018. HIGHLIGHTSDue to the low initial costs and ease of employment of agrosilvopastoral systems, the cultivation of yerba-mate constitutes an alternative for small properties in the RS to the diversification of production.The isolates of Fusarium spp. were submitted to the UPGMA analysis and grouped by the similarity between the characters averages.Through the UPGMA clustering test, the thirty-nine isolates of Fusarium spp. were allocated to seven large groups.The analysis of the TEF 1-α gene region was enough to discriminate species of Fusarium spp.The reflex symptoms resulted from the interaction of Fusarium spp. isolates with yerbamate roots. ABSTRACTThe cultivation of yerba-mate (Ilex paraguariensis) has been intensified in the State of Rio Grande do Sul, as result of the valuation of the price paid to the producer. However, studies related to Fusarium pathosystem vs. yerba-mate are still insufficient, so that many producers have faced significant losses in herbal production due to the occurrence of the roots rotting. Considering the above, the objectives of this study were: a) morphologically characterize the Fusarium spp. isolates collected in sick plants of yerba-mate; b) select efficient morphological characters on separating the Fusarium spp. isolates in similarity groups; c) identify the Fusarium spp. isolates to species level through the sequencing of the genomic region of elongation factor 1-α (TEF-1α); and d) testing the pathogenicity of the Fusarium spp. isolates selected based on the morphological characterization. For such, collections for the pathogen isolates were made in five cities and the collection points were georeferenced. Thirty-nine isolates were morphologically characterized by variables as mycelial growth, sporulation, macroconidia length and width, microconid format, colonies pigmentation and formation of chlamydospore, and tested for pathogenicity by substrate inoculation. The variables used in the morphological characterization were efficient in discriminating the isolates in seven groups, especially length of macronidia associated to sporulation. Seven pathogenic isolates of Fusarium spp. were identified, also through molecular sequencing of the TEF-1α gene region. The sequencing of the TEF-1α region consolidated the identification of pathogenic isolates as F. solani and F. oxysporum. v.24 n.3 2018 MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF FUSARIUM SPP. PATHOGENIC TO Ilex Paraguariensis 210 CERNE MEZZOMO et al.

The Effect of Fungi Accompanying cuscuta on the Germination Rates of Ocimum and cuscuta Seeds and Their Molecular Diagnosis

“…Other fungi showed varying results in the effect in the seeds of the Cuscuta and Ocimum. The reason for the difference in the pathogenetic ability of isolates may be due to the genetic heterogeneity between isolates and individuals of the same species, especially that they were isolated from different plants and regions, or the difference in the amount of secondary metabolic compounds secreted by them, such as their ability to secrete a number of enzymes that decompose the host cell walls that help to penetrate the host, including enzymes (Chitinase, Cellulose, Protease and polygalcturinase) enzymes play the main role in parasitizing living cells, which leads to rotting of seeds and preventing them from germinating and affecting the embryo because the infection of the embryo is the main reason for reducing the percentage In addition ,there is a family specialization between the pathogen and the host (28,8,24,29,30). It also has the ability to produce mycotoxins that kill seed embryos, which have a role in disease events by inhibiting the work of enzymes and the permeability of cell membranes and acting as an antidote that leads to a lack of plant growth factors (31,32,33) Table 4.…”

DOENÇAS FÚNGICAS DA CULTURA DA ERVA-MATE (Ilex paraguariensis) NO BRASIL

“…Os autores concluíram que o melhor crescimento, desenvolvimento e maior resistência da erva-mate ocorreram com os maiores níveis de sombreamento. Mezzomo et al (2018b) realizaram a caracterização morfofisiológica e a identificação molecular de isolados patogênicos de Fusarium spp. As amostras de raízes e as mudas foram obtidas de ervais localizados nos municípios de Anta Gorda, Arvorezinha, Putinga, Ilópolis e Machadinho, no Rio Grande do Sul.…”

“…Os autores identificaram sete isolados como patogênicos, e as espécies F. solani e F. oxysporum como as principais causadoras da podridão-de-raízes nos ervais do Rio Grande do Sul. Os resultados obtidos por Mezzomo et al (2018b) et al (2018), esta espécie teve o seu primeiro relato em 2018, com mortalidade superior à 5% dos ervais avaliados em São Mateus do Sul e Arvorezinha.…”

Molecular characterization and vegetative compatibility groups of <i>Fusarium</i> spp. pathogenic to <i>Ilex paraguariensis</i> A. St.-Hil.

“…The experiment was conducted at the "Elocy Minussi" Phytopathology Laboratory of the Center of Rural Sciences of the Federal University of Santa Maria, Santa Maria, Rio Grande do Sul state (RS), Brazil. For the molecular characterization and the VCG test, a Fusarium oxysporum (I6AR2) and six other isolates from Fusarium solani (I1AR1, I8AR1, M3AR2, M4, M5AR2 and M7C1) pathogenic to mate, as described by Mezzomo et al (2018), collected in RS state, and deposited in the mycology collections of the same laboratory, where they remain stored in refrigeration in Eppendorff tubes, containing saline solution 0.85% NaCl (Table 1).…”