ABSTRACT One of the limiting factors for pecan production is the incidence of disease caused by Fusarium spp. which are a threat to orchards in the south of the country. Therefore, the study aimed to confirm the pathogenicity and evaluate the morphophysiological and molecular characteristics of Fusarium spp. associated with pecan in Rio Grande do Sul and Paraná. For this, samples of symptomatic plant material were collected, and potentially pathogenic isolates were evaluated for pathogenicity, by immersing the roots of the plants in a spore suspension of Fusarium spp. In addition, the severity of the disease was assessed using a rating scale according to the symptoms expressed by the plants. The isolates were also analyzed for morphophysiological variability, through evaluations of mycelial growth, colony and aerial mycelium pigmentation, and characteristics of reproductive structures. Molecular characterization was performed which amplify the region of the 1-alpha elongation factor and sequencing. Nineteen isolates were obtained, which were considered pathogenic, however, there was variability in their aggressiveness and morphophysiological characteristics. In addition, the sequencing was used to identify different species. Therefore, species of Fusarium are responsible for the occurrence of wilt in pecan in southern Brazil.

Abstract Cabreúva (Myrocarpus frondosus Allemão) is a native species with ecological, ornamental, medicinal, and timber potential. This study aimed to evaluate the physical, physiological, and sanitary quality of Myrocarpus frondosus diaspores over 360 days in different storage environments. The initial characterization of the batch included the weight of 1,000 seeds, moisture content, electrical conductivity, germination potential (with substrates being between and on sand or vermiculite, and a paper roll) and sanitary quality (blotter test). The diaspores were stored in a room with ambient conditions, a dry and cold room, a wet and cold chamber, and a refrigerator. Evaluations were performed at 0, 90, 180, 270, and 360 days. The substrates between sand and between vermiculite are recommended for the germination of diaspores. Diaspores showed no recalcitrant behavior in relation to storage and can be stored in a dry and cold room (18 °C and 49% RH) for 360 days, with 57% germination. Fungal incidence increased the deterioration of the diaspores after 180 days of storage in a cold and dry environment.

O trabalho tem como objetivo analisar o comportamento espectral de folhas de Eucalyptus globulus atacadas em quatro diferentes níveis de severidade pelo fungo Mycosphaerella spp. em diferentes posições na copa da árvore, nas quatro estações climáticas, considerando duas regiões do espectro eletromagnético: visível e infravermelho próximo. Foram realizadas coletas de material vegetativo em todas as estações climáticas, em diferentes posições na árvore (base, meio e extrato superior da copa). Em laboratório, as folhas foram classificadas em quatro níveis de severidade (sadio, pouco, medianamente e muito atacado) e posteriormente efetuadas as medidas de reflectância espectral com auxílio de um espectrorradiômetro. O comportamento espectral das folhas de Eucalyptus globulus é característico de acordo com o nível de severidade da doença, diferindo dos demais principalmente em altos níveis de infecção por Mycosphaerella spp. e diferenciam-se principalmente de folhas sadias e de folhas pouco atacadas, em ambas as regiões do espectro eletromagnético, esse comportamento ocorre para as diferentes posições da copa e estações climáticas variando a quantidade de energia refletida. Conclui-se que a reflectância das folhas de Eucalyptus globulus atacadas por Mycosphaerella spp. difere de acordo com a posição na copa da árvore e a estação climática em que foram coletadas e níveis avançados da severidade da doença.

The study aims to analyze the spectral behavior of leaves of Eucalyptus globulus attacked in four different severity levels by Mycosphaerella spp. in different positions in the canopy of the tree in the four seasons, considering two regions of the electromagnetic spectrum: visible and near infrared. The plant material was collected in all seasons, in different positions in the tree (base, middle and top of the canopy extract). In the laboratory, leaves were classified into four levels of severity (healthy, little, medium and heavy fire) and then made measurements of spectral reflectance measured with a spectroradiometer. The spectral behavior of Eucalyptus globules leaves is characteristic according to the severity degree of the disease, differing primarily in the other high levels of infection by Mycosphaerella spp. and differ mainly of healthy leaves and leaves which are little attacked, in both regions of the electromagnetic spectrum, this behavior occurs for different treetop positions and climate seasons, varying the amount of reflected energy. It is concluded that the reflectance of the Eucalyptus globules leaves attacked by Mycosphaerella spp. differs according to the position in the tree crown and the weather station when they were collected and to the advanced levels of disease severity.

RESUMO Em 2004, foram constatados sintomas da doença podridão-de-raízes em ervais nos municípios da região alta do Vale do Taquari, RS. Com o auxílio de técnicos da EMATER, fez-se um levantamento dos municípios que possuíam ervais com sintomas. Em 10% dos ervais afetados, coletaram-se amostras de raízes que foram enviadas para análise no Laboratório de Fitopatologia pertencente ao Departamento de Defesa Sanitária/CCR/UFSM. Foram isoladas e identificadas cinco diferentes espécies do fungo Fusarium associadas à doença: Fusarium oxysporum, Fusarium solani, Fusarium decemcellulare, Fusarium tabacinum e Fusarium tricinctum. Todas as espécies se mostraram patogênicas quando inoculadas em plantas de erva- mate (Ilex paraguariensis A. St.-Hil.). No momento da coleta das amostras, levantaram-se informações sobre o manejo do erval e discutiu-se a similaridade entre os sintomas apresentados na erva-mate e em culturas agronômicas bem como hipóteses sobre a origem do inóculo de Fusarium spp. que proporcionou a contaminação dos ervais.

ABSTRACT In 2004, symptoms of root rot disease were observed in erva-mate plantings in high areas of Region Taquari Valley, RS. With the help of EMATER, the municipal districts presenting plantings with symptoms were surveyed. In 10% of the affected plantings, root samples were collected and sent for analysis at the Plant Disease Laboratory at the Department of Plant Protection/CCR/UFSM. Five different species of at fungus Fusarium associated with the disease were isolated and identified: Fusarium oxysporum, Fusarium solani, Fusarium decemcellulare, Fusarium tabacinum and Fusarium tricinctum. All species were pathogenic when inoculated in erva-mate plants (Ilex paraguariensis A. St.-Hil.). At the moment of sampling, information about the management of the erva-mate plantings was obtained and the similarity between the symptoms presented in erva-mate and in agronomic crops discussed, as well as hypotheses on the origin of the inoculum of Fusarium spp. that infected the erva-mate plantings.