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Colletotrichum menezesiae A. Reis, W.A.S. Vieira & M.P.S. Câmara, sp. nov. (Fig. 2) MycoBank: MB848223 Systematic position:—Ascomycota, Pezizomycotina, Sordariomycetes, Hypocreomycetidae, Glomerellales, Glomerellaceae. Type:— BRAZIL. Minas Gerais: Ibirité, from anthracnose lesions on Sicyos edulis fruit, Feb 2022, A. Reis. Holotype VIC49404. Ex-type living culture COAD3523. Etymology:—Named in honour of Maria Menezes, retired mycologist from Universidade Federal Rural de Pernambuco (UFRPE), for her contribution to Brazilian mycology and phytopathology. Colonies on PDA apricot coloured from the aerial view, reverse orange, aerial mycelium sparse, growth rate at 25 °C 5.7–6.3 mm.dia(average 5.9 ± 0.3 mm. dia-1). Conidiogenous cells hyaline, smooth-walled, cylindrical to ampulliform, often extending to form a new conidiogenous locus (percurrent proliferation). Conidiophores hyaline, smooth-walled, septate, unbranched, 8.4–23.7× 2.4–3.2 μm (av. 14.7 ± 4.4 × 2.9 ± 0.3 μm) on PDA, 12.4–19.7× 3–3.2 μm (av. 16.3 ± 3.2 × 3.23 ± 0.1 μm) on Sicyos edulis. Conidia one-celled, hyaline, smooth-walled, cylindrical with rounded ends, contents appearing granular. Conidia on PDA 9.6–13.8 × 3.4–4.4 μm (av. 10.7 ± 1.1 × 3.8 ± 0.3 μm). Conidia on Sicyos edulis 8.2–13.3 × 2.9–3.8 μm (av. 11.1 ± 1.6 × 3.4 ± 0.2 μm). Appressoria in slide cultures, single, medium to dark brown, smooth-walled, irregular shape, solitary, 6.2–8.9 × 4.2–8 μm (av. 7.2 ± 0.8 × 5.7 ± 0.9 μm). Setae produced only on Sicyos edulis, abundant, long, dark brown, smooth-walled, two septate, sometimes with constriction in the apical septum, base truncate, tip acute, 40–65 × 2.9–4 μm (av. 51.5 ± 7.5 × 3.3 ± 0.3 μm). Sclerotia, chlamydospores, and sexual morph not observed. -1 Geographic distribution and host range:— Known from Sicyos edulis from Ibirité (Minas Gerais state) and Tijucas (Santa Catarina state, isolate CMM3469), Brazil., Published as part of Vieira, Willie Anderson Dos Santos, Costa, Christiane Almeida Da, Câmara, Marcos Paz Saraiva, Michereff, Sami Jorge & Reis, Ailton, 2023, Colletotrichum menezesiae sp. nov.: a novel species causing anthracnose on chayote in Brazil, pp. 80-86 in Phytotaxa 597 (1) on page 84, DOI: 10.11646/phytotaxa.597.1.9, http://zenodo.org/record/7918839

The population structure of Monosporascus cannonballus, which causes vine decline in melons, was assessed based on the determination of mycelial compatibility groups (MCGs) in a collection of 58 isolates obtained from seven melon fields in three municipalities of Northeastern Brazil. For comparison, an additional 11 isolates of M. cannonballus from Spain were included in the analysis. MCGs were determined through comparisons of paired isolates growing on PDA culture media in the dark at 30ºC in various combinations. The Brazilian isolates were assigned into four MCGs: MCG-1 (n = 35 isolates), MCG-2 (n = 20), MCG-3 (n = 2), and MGC-4 (n = 1). MCG-1 and MCG-2 included isolates from all surveyed areas. The Spanish isolates were assigned into six different MCGs, and none of them were compatible with the Brazilian isolates. The genetic structure was determined using the frequencies of MCGs and genotypic diversity indices. The maximum genotypic diversity was 6.9 and 54.5% for the Brazilian and Spanish populations, respectively. The low level of genetic diversity in the M. cannonballus population from Northeastern Brazil suggests that breeding melons for disease resistance may be a promising strategy for the region. The population structure of Monosporascus cannonballus, which causes vine decline in melons, was assessed based on the determination of mycelial compatibility groups (MCGs) in a collection of 58 isolates obtained from seven melon fields in three municipalities of Northeastern Brazil. For comparison, an additional 11 isolates of M. cannonballus from Spain were included in the analysis. MCGs were determined through comparisons of paired isolates growing on PDA culture media in the dark at 30ºC in various combinations. The Brazilian isolates were assigned into four MCGs: MCG-1 (n = 35 isolates), MCG-2 (n = 20), MCG-3 (n = 2), and MGC-4 (n = 1). MCG-1 and MCG-2 included isolates from all surveyed areas. The Spanish isolates were assigned into six different MCGs, and none of them were compatible with the Brazilian isolates. The genetic structure was determined using the frequencies of MCGs and genotypic diversity indices. The maximum genotypic diversity was 6.9 and 54.5% for the Brazilian and Spanish populations, respectively. The low level of genetic diversity in the M. cannonballus population from Northeastern Brazil suggests that breeding melons for disease resistance may be a promising strategy for the region.

Corky dry rot, caused by Fusarium semitectum, is the main postharvest disease of melons in Brazil. This study investigated the effects of wounding, humidity, temperature, and inoculum concentration on the severity of corky dry rot under controlled conditions. Cantaloupe and honeydew melon types were inoculated by spraying conidial suspensions of three F. semitectum isolates. In all experiments, the tested F. semitectum isolates did not differ in relation to disease severity, but, the cantaloupe melon showed higher levels of severity. No lesions appeared on fruits that lacked wounds, and increasing wound age reduced lesion severity. Melons that were inoculated with F. semitectum developed symptoms regardless of the presence or absence of a moist chamber at the post-inoculation stage, but the lesions were larger under moist chamber conditions. There were no symptoms at 10°C, but a temperature increase from 15 to 25°C resulted in a disease severity increase. The largest lesions were observed when both melon types were inoculated with a concentration of 10(6) conidia mL-1, but even the lowest concentration (10¹ conidia mL-1) was sufficient for causing lesions. Injury reduction and/or the acceleration of melon healing, as well as environmental variable control and a reduction of inoculum sources, are essential to reducing corky dry rot severity. A podridão seca causada por Fusarium semitectum é a principal doença pós-colheita do melão no Brasil. Este estudo investigou o efeito de ferimento, umidade, temperatura e concentração de inóculo na severidade da podridão seca em condições controladas. Frutos de melão dos tipos cantaloupe e honeydew foram inoculados por meio da pulverização de suspensão de conídios de três isolados de F. semitectum, inoculados separadamente. Em todos os experimentos os isolados de F. semitectum testados não diferiram em relação à severidade da doença, porém, a variedade cantaloupe apresentou maiores níveis de severidade da doença. Não houve lesões em frutos sem ferimento e o incremento na idade do ferimento reduziu a severidade. Melões inoculados com F. semitectum desenvolveram sintomas independentemente de câmara úmida pós-inoculação, mas as lesões foram maiores em condições de câmara úmida. Não houve sintomas a 10°C, mas o aumento da temperatura de 15 para 25°C resultou num incremento da severidade da doença. As maiores lesões foram observadas na concentração de inóculo de 10(6) conídios mL-1 nos dois tipos de melão, mas a menor concentração (10¹ conídios mL-1) foi suficiente para causar leões. A diminuição de injúrias nos frutos de melão e/ou a aceleração da cicatrização, bem como o controle das variáveis ambientais e a redução das fontes de inóculo são essenciais para redução da severidade da podridão seca.

A antracnose, causada por Colletotrichum gloeosporioides, é uma importante doença da pinha (Annona squamosa) no Brasil e em nível mundial. Devido à inexistência de métodos padronizados para quantificação dessa doença, foi desenvolvida uma escala diagramática com níveis de 1, 2, 5, 10, 20 e 40% de área foliar lesionada. A escala diagramática foi validada por 10 avaliadores, baseado em 48 folhas de pinha com diferentes níveis de severidade da antracnose, mensurados previamente com o programa Assess®. A acurácia, a precisão e a reprodutibilidade das estimativas de cada avaliador foi determinada por regressão linear simples entre a severidade real e a estimada, com e sem o auxílio da escala. Com a escala, os avaliadores obtiveram melhores níveis de acurácia e precisão das estimativas, com os erros absolutos concentrando-se na faixa de 10%. Os avaliadores apresentaram elevada repetibilidade (91%) e reprodutibilidade (³90% em 94,5% dos casos) das estimativas com a utilização da escala. Portanto, a escala diagramática proposta é adequada para avaliação da severidade da antranose da pinha. Anthracnose caused by Colletotrichum gloeosporioides is an important disease of custard apple (Annona squamosa) in Brazil and worldwide. Due to the inexistence of standard methods for the assessment of that disease, a diagrammatic scale was developed with 1, 2, 5, 10, 20 and 40% of diseased leaf area. The diagrammatic scale was validated by 10 raters using 48 custard apple leaves with different levels of anthracnose severity previously measured by the software Assess®. The accuracy, precision and reproducibility estimative of each rater were determined by simple linear regression between actual and estimated severity, with and without the use of the scale. With the scale, the raters obtained better levels of accuracy and precision, with absolute errors concentrating around 10%. Raters showed high repeatability (91%) and reproducibility (³90% in 94.5% of the cases) of the estimates by using the scale. The proposed diagrammatic scale is suitable for the evaluation of anthracnose severity in custard apple.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2019-12-03T15:28:08Z No. of bitstreams: 1 Tiago Bezerra Torres.pdf: 1588795 bytes, checksum: 1577df939fc93e52ff2fa63f00edd6f5 (MD5) Made available in DSpace on 2019-12-03T15:28:08Z (GMT). No. of bitstreams: 1 Tiago Bezerra Torres.pdf: 1588795 bytes, checksum: 1577df939fc93e52ff2fa63f00edd6f5 (MD5) Previous issue date: 2019-07-30 Cowpea fusarium wilt caused by Fusarium oxysporum f. sp. tracheiphilum (Fot) is reported in many producing regions causing production and productivity losses in Brazil and worldwide. There is no efficient control measure for this disease, as the pathogen produces chlamydospore-like resistance structures capable of remaining inactive for long periods of time under adverse conditions. The integrated use of host genetic resistance coupled with the application of antagonist yeasts is presented as a control alternative to this disease. In this context, the objective of this work was to investigate the pathogenicity and resistance of different cowpea genotypes to Fot, as well as the application of antagonistic yeast strains as biological control agents of cowpea fusarium wilt. Fot isolates were evaluated by the method of dipping or immersing roots of conidial suspended plants using two genotypes considered susceptible to the pathogen under greenhouse conditions. Isolates CFS-296 and CMM-732 promoted disease with wilting, yellowing and reduced growth in cv. BR-17 Gurguéia and IPA-206. From these isolates, twenty genotypes were characterized for resistance and interference in height, root length, number of leaves, number of branches, stem diameter, green biomass and plant dryness in relation to the disease. The genotypes presented different resistance to disease in relation to pathogen isolates, affecting the morphological characteristics of the plants. All genotypes were highly resistant to CMM-732, except the Casa Amarela-06 genotype, which was susceptible. While for CFS-296, six genotypes were moderately resistant, five susceptible and nine highly susceptible. Thirty strains of yeast isolated from cowpea plant parts were selected and characterized for inhibitory and antibiotic action in vitro on the most aggressive isolate (CMM-732), and compared with the two pathogenic isolates, demonstrating that the strains CFS-644, CFS-652 and CFS-699 were effective in reducing mycelial growth for CFS-296, as well as CFS-738 for CMM-732 isolate. In the bioprotective assay, cowpea seeds and 6-day old twinned plants treated with four yeasts by immersion and spraying at a concentration of 1x106 cells mL-1 respectively, as well as inoculated with the two pathogenic isolates, showed a reduction of 12-46%. of the severity of the disease. In particular, the CFS-652-treated Encruzilhada-04 genotype reduced the disease infection by 46%. Use of yeast biocontrol combined with host resistance has been shown to be an alternative management approach to fusarium wilt. A murcha-de-fusário do feijão-caupi causada por Fusarium oxysporum f. sp. tracheiphilum (Fot) é relatada em muitas regiões produtoras provocando perdas na produção e produtividade no Brasil e no mundo. Não existe medida de controle eficiente para esta doença, pois o patógeno produz estruturas de resistência do tipo clamidósporos capazes de permanecer inativo no solo por um longo período sobre condições adversas. O uso integrado da resistência genética hospedeira aliada a aplicação de leveduras antagonistas, apresenta-se como uma alternativa de controle a essa doença. Neste contexto, o objetivo deste trabalho foi investigar a patogenicidade e a resistência de diferentes genótipos de feijão-caupi a Fot, bem como a aplicação de cepas de leveduras antagônicas como agentes de controle biológico da murcha-de-fusário do caupi. Os isolados de Fot foram avaliados pelo método de dipping ou imersão de raízes de plantas em suspensão de conídios utilizando dois genótipos considerados suscetível ao patógeno, sobre condições de casa de vegetação. Os isolados CFS-296 e CMM-732 promoveram a doença apresentando murcha, amarelecimento e redução do crescimento em plantas na cv. BR-17 gurguéia e IPA-206. A partir destes isolados, vinte genótipos foram caracterizados quanto a resistência e a interferências na altura, comprimento de raiz, número de folhas, número de ramos, diâmetro do caule, biomassa verde e seca das plantas em relação a doença. Os genótipos apresentaram diferentes resistências a doença em relação aos isolados do patógeno, afetando as características morfológicas das plantas. Todos os genótipos apresentaram altamente resistente a CMM-732, exceto o genótipo Casa Amarela-06 que se mostrou suscetível. Enquanto para CFS-296, seis genótipos apresentaram moderadamente resistentes, cinco suscetível e nove altamente suscetível. As trinta cepas de leveduras isoladas de partes da planta de feijão-caupi, foram selecionadas e caracterizadas quanto a ação inibitória e antibiótica in vitro sobre o isolado mais agressivo (CMM-732), e confrontadas com os dois isolados patogênicos, demonstrando que as cepas CFS- 644, CFS-652 e CFS-699 foram eficiente na redução do crescimento micelial para CFS-296, assim como CFS-738 para o isolado CMM-732. No ensaio bioprotetivo, as sementes de caupi e as plantas com 6 dias de geminadas tratadas com quatro leveduras por imersão e pulverização na concentração de 1x106 células mL-1 respectivamente, bem como inoculadas com os dois isolados patogênicos, apresentaram redução de 12-46% da severidade da doença. Em destaque, o genótipo Encruzilhada-04 tratado com CFS-652 reduziu em 46% a infecção da doença. Utilização do biocontrole com leveduras aliada a resistência hospedeira demonstrou ser uma alternativa de manejo a murcha-de-fusário.