Resistance to diseases of sour, sweet and wild passion fruit genotypes

The cultivation of passion fruit is important for Brazil, since the country is currently the largest producer and consumer of fruit in the world. However, the fields of passion fruit still face important problems due to the incidence and severity of diseases in the field. Thus, the present study aimed to assess resistance to bacterial and fungal diseases in 13 genotypes of sour, sweet and wild passion fruit, in field conditions in the Distrito Federal, Brazil. For this, a field experiment was installed in a randomized block design, with four replications and 13 treatments (genotypes). The characteristics of incidence, severity and degree of resistance for bacteriosis, septoriosis, scab and anthracnose diseases were evaluated in 5 fruits per plot of each genotype. Genetic parameters of the evaluated traits were also estimated. High heritability values and CVg/Cve ratio were observed for most of the evaluated characteristics. The genotypes presented mean values of incidence and severity of bacteriosis, septoriosis, scab and anthracnose different among them, and the one that presented the best results in the degree of resistance for all diseases was F1 (MAR20 # 24 x ECL7 P1 R4).

Alternative products to control late season diseases in soybeans / Produtos alternativos para o controle de doenças de final de ciclo na soja

In the last crop seasons, the complex of late season diseases (CLSD) of soybean (Glycine max L. (Merrill)), has been causing considerable reductions in the crop yield. Currently, there are no cultivars resistant to all pathogens that causes CLSD. The present study evaluated the effect of applying the acibenzolar-S-methyl resistance inducer, alternative products and fungicide on the severity of CLSD in the soybean cultivar BMX Potência RR during the 2013/2014 and 2014/2015 crops, in the field. The treatments for the experiments were: 1 - control (water); 2 - acibenzolar-S-methyl; 3 - calcium; 4 - micronutrients: copper, manganese and zinc; 5 - micronutrients: manganese, zinc and molybdenum; 6 - nitrogen-potassium fertilizer; 7 - Ascophyllum nodosum and 8 - azoxystrobin + cyproconazole with the addition of the adjuvant. Four applications of alternative products and two of fungicide were carried out in both harvests. A diagrammatic scale assessed the severity of CLSD at the phenological stage R7.1. The acibenzolar-S-methyl resistance inducer, alternative products (macro and micronutrients) and A. nodosum had no effect on the severity of CLSD in the two harvests. The fungicide (azoxystrobin + cyproconazole) reduced the severity of CLSD and prevented damage to productivity in both experiments.

Nas últimas safras, o complexo de doenças de final de ciclo (DFC) da soja (Glycine max L. (Merrill)), vem provocando reduções consideráveis no rendimento da cultura. Atualmente, não há variedades resistentes a todos os patógenos causadores das DFC. O objetivo do presente trabalho foi avaliar o efeito da aplicação do indutor de resistência acibenzolar-S-methyl, produtos alternativos e fungicida na severidade de DFC na cultivar de soja BMX Potência RR durante as safras 2013/2014 e 2014/2015, em campo. Os tratamentos para os experimentos foram: 1 - testemunha (água); 2 - acibenzolar-S-methyl; 3 - cálcio; 4 - micronutrientes: cobre, manganês e zinco; 5 - micronutrientes: manganês, zinco e molibdênio; 6 - adubo NK; 7 - Ascophyllum nodosum e 8 - azoxistrobina + ciproconazol com adição do adjuvante. Foram realizadas quatro aplicações dos produtos alternativos e duas do fungicida, nas duas safras. A severidade de DFC foi avaliada por escala diagramática no estádio fenológico R7.1. O indutor de resistência acibenzolar-S-methyl, os produtos alternativos (macro e micronutrientes) e A. nodosum não apresentaram efeito sobre a severidade das DFC nas duas safras. O fungicida (azoxistrobina + ciproconazol) reduziu a severidade das DFC e evitou danos a produtividade nos dois experimentos.

Molecular Identification of Endophytic Fungi Isolated from Needle Leaves of Conifers in Bohyeon Mountain, Korea

Fungal endophytes are microfungi that live in plants without causing apparent symptoms of infection. This study was conducted to identify endophytic fungi isolated from leaves of coniferous trees in Bohyeon Mountain of Korea. We collected leaves of two species of coniferous trees, Pinus densiflora and Pinus koraiensis, from 11 sites in the study area. A total 58 isolates were obtained and identified using molecular and morphological characteristics. Four species of endophytic fungi were isolated from P. densiflora: Lophodermium conigenum, Leotiomycetes sp., Septoria pini-thunbergii, and Polyporales sp., while two fungal species were isolated from P. koraiensis: Eurotiomycetes sp. and Rhytismataceae sp. The most frequently isolated species were L. conigenum and S. pini-thunbergii.

First Report of Septoria centellae Associated with Leaf Spot of Centella asiatica in Korea

Septoria centellae associated with leaf spot of Centella asiatica is reported for the first time in Korea. The fungus is described and illustrated in detail. It is also compared with related species of Septoria present on Centella and Hydrocotyle spp. with taxonomic comments. Two monoconidial isolates from Jeju and Wando were successfully cultured and have been deposited in the Korean Agricultural Culture Collection.

Escala diagramática para avaliação de severidade de mancha-de-septoria em girassol / Diagrammatic scale for assessment of septoria-leaf-spot severity in sunflower

A falta de um método-padrão de quantificação visual para doenças foliares pode levar a estimativas imprecisas da severidade dessas doenças, induzindo os avaliadores a conclusões erradas. O objetivo deste trabalho foi desenvolver uma escala diagramática para avaliação da mancha-de-septoria em girassol, causada por Septoria helianthi. Uma escala diagramática com cinco níveis (2; 12; 26; 48,0; e 71 por cento) foi desenvolvida e validada para quantificar a severidade da mancha-de-septoria em girassol. A escala considerou o limite de severidade máxima da doença observado no campo, e os níveis intermediários seguiram incrementos logarítmicos, obedecendo-se à "Lei do estímulo de Weber-Fechner". Inicialmente, a estimativa da severidade foi feita sem auxílio da escala em 30 folhas, com diferentes níveis de severidade, por oito indivíduos, sem experiência na avaliação de doenças. Em seguida, os mesmos avaliadores utilizaram a escala diagramática proposta. As avaliações com a escala diagramática foram mais precisas e acuradas nas estimativas de todos os avaliadores, não ocorrendo erro sistemático na superestimativa ou subestimativa da doença entre estes. A escala diagramática proposta foi considerada adequada para estimar a severidade de mancha-de-septoria em girassol.

The lack of a standardized visual method may lead to inaccurate estimative of severity and wrong conclusions. The objective of this research was to develop a diagrammatic scale to assess the severity of septoria leaf spot in sunflower, caused by Septoria helianthi. A diagrammatic scale with five levels of disease severity (2; 12; 26; 48; and 71 percent) was developed and validated to assess septoria leaf spot in sunflower. The scale was developed considering the maximum limit of disease severity observed in the field and the intermediate values followed logarithmic increments according to the "Stimulus Law by Weber-Fechner". Initially the estimates of severity were performed without the use of the scale in 30 leaves with different levels of severity. Validation was carried out by eight appraisers, without previous practice in assessing septoria leaf spot in sunflower. Then, the appraisers estimated the severity of the same leaves previously assessed using the proposed diagrammatic scale. Assessments with the diagrammatic scale were of great precision for all raters and did not constitute systematic mistakes in overestimating or underestimating the disease severity. The proposed diagrammatic scale was considered adequate to estimate septoria-leaf-spot severity in sunflower.

Incidência e severidade de septoriose (septoria passiflorae sydow) em mudas de 48 genótipos de maracujazeiro azedo, sob casa de vegetação no distrito federal / Incidence and severity of septoriosis (septoria passiflorae) in seedling of 48 genotypes of passionfruit (passiflora edulis f. flavicarpa) growing in greenhouse at distrito federal

O maracujazeiro é atacado por diversos patógenos, entre eles o fungo Septoria passiflorae, causador da septoriose. Objetivando-se analisar a reação de genótipos de maracujá azedo a septoriose, foi conduzido um experimento com mudas, em casa de vegetação, na Estação Biológica da Universidade de Brasília, em blocos casualizados com quatro repetições e 6 plantas por parcela, testando-se 48 genótipos. A inoculação do patógeno foi feita por aspersão na planta com, suspensão contendo concentração de 5,0 x 106 esporos/ml, produzidos em meio de cultura. Foram feitas duas avaliações, com intervalos de 25 dias. As plantas foram avaliadas de acordo com a escala de notas de 1 a 4, sendo 1 para Plantas sem sintomas; 2 ? Lesões esparsas nas folhas; 3 ? Lesões coalescendo tomando mais de 25 % do limbo foliar; 4 ? Planta com desfolha. Houve diferenças significativas entre os genótipos para todos os parâmetros avaliados. Destacaramse os genótipos MAR 20-09, MAR 20-53 e MAR 20-60, como mais resistentes a septoriose em condições de cultivo protegido, enquanto os genótipos MAR 20-43, MAR 20-39 e MAR 20-01 foram os mais suscetíveis. (AU)

Passionfruit is affected by many diseases caused by pathogenic fungi. One of them is Septoria passiflorae, causing septoriosis. In order to evaluate the reaction of Passionfruit genotypes to septoriosis, an essay was carried out in greenhouse conditions in the experimental station of Universidade de Brasília. It was designed by randomized blocks with four replications and six plants per plot. A number of 48 genotypes were tested. The inoculation was done by spraying a suspension of conidia at 5,0 x106 spores/ml. Six evaluations were done, at 7 days intervals. The scores were done using a lesion scale graded from 1 to 4, 1- no visual disease, 2-spread lesions on the leaves, 3- coalescent lesions with more than 25% of leaf surface, 4-falling leaves. The plants had small significant differences between the averages of grades, so there was little reduction of grades from first to second evaluation time (50 days), probably by theincrease of leaf area. The genotypes MAR 20-09, MAR 20-53 and MAR 20-60, were considered resistant to septoriosis at greenhouse conditions, and the MAR 20-43, MAR 20-39 e MAR 20-01 were more susceptible. (AU)

Morphometric Studies on the Genus Septoria in Korea (I)

The mycoflora of Korea was rather poorly studied in the past and the fungi belonging to the genus Septoria are no exception. For this reason, taxonomic studies on Septoria have been initiated, with the eventual aim of producing a monograph of the Septoria species present in Korea. The present study circumscribes 10 species; viz., Septoria artemisiae, S. callistephi, S. chrysanthemella, S. erigerontis, S. lycopersici, S. lysimachiae, S. oenotherae, S. phlogis, S. rohlenae, and S. sonchi. Distinguishing morphological characters are described and illustrated for each species.