Inoculação de Fusarium oxysporum f. sp. phaseoli em sementes de feijoeiro através de restrição hídrica

Costa, Maria Luiza Nunes; Machado, José da Cruz; Guimarães, Renato Mendes; Pozza, Edson Ampélio; Oride, Denis

doi:10.1590/s1413-70542003000500008

Cited by 41 publications

(42 citation statements)

References 8 publications

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“…In this case, to estimate pre-emergent seed death for each treatment, the influence of mannitol in the control treatments was observed. The effect of the water restrictor was then subtracted from the treatments with fungus, thus eliminating any possible repressive influence of the restrictor may have on physiological seed quality (COSTA et al, 2003).…”

Section: Resultsmentioning

confidence: 99%

Transmission ofStenocarpella maydisby maize seeds

Siqueira

Barrocas

Machado

et al. 2016

Revista Ciência Agronômica

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-Stenocarpella maydis is one of the main fungi associated with maize seeds, being a causative agent of stalk and ear rot, a disease which causes considerable losses for crop-producing regions in Brazil. The organism is considered to be a pest, subject to sanitary standardisation in current programs of seed certification in the country. The aim of this study was to evaluate the transmission rate of the fungus from infected maize seeds. Seeds were inoculated with two isolates using a method of physiological conditioning, in which the seeds are kept in contact with colonies of the fungus for 24 (P1), 48 (P2), 72 (P3) and 96 (P4) hours. Two cultivars were used, one susceptible (C1) and one moderately resistant (C2), and the trial carried out at two temperatures (20 °C and 25 °C). The inoculated seeds were distributed individually into plastic cups containing substrate. The plants were evaluated daily for stand and the appearance of post-emergent symptoms. Based on the number of dead seeds, transmission rates reached a maximum of 90.5% at the P4 inoculum potential, this rate being greater than transmission rates achieved for symptomatic and asymptomatic infection in emerged plants. For the total transmission rate, transmission of the pathogen was seen at all inoculum potentials; these values varying from 25% for cultivar C2 at potential P1 and a temperature of 20 °C, to 93% for cultivar C2 at potential P3 and a temperature of 25 °C. RESUMO -Stenocarpella maydis é um dos principais fungos que se associam às sementes de milho, sendo um dos agentes causais da podridão do colmo e da espiga, que ocasiona perdas consideráveis em regiões produtoras desta cultura no Brasil. O referido organismo tem sido enquadrado como uma praga sujeita a padronização sanitária em programas de certificação de sementes vigentes no país. O objetivo nesse trabalho foi avaliar a taxa de transmissão do referido fungo a partir de sementes de milho infectadas. As sementes foram inoculadas com dois isolados pelo método de condicionamento fisiológico no qual as sementes são mantidas em contato com colônias do fungo por 24 (P1), 48 (P2), 72 (P3) e 96 (P4) horas. Foram utilizadas duas cultivares, uma suscetível (C1) e outra moderadamente resistente (C2) e o ensaio conduzido em duas temperaturas (20 e 25 °C). As sementes inoculadas foram distribuídas individualmente em copos plásticos contendo substrato. As plantas foram avaliadas diariamente quanto ao estande e aparecimento de sintomas em pós-emergência. Com base em sementes mortas, as taxas de transmissão alcançaram o percentual máximo de 90,5% para o potencial de inóculo P4, sendo esta taxa mais alta do que as alcançadas pelas taxas de transmissão para infecção sintomática e assintomática em plantas emergidas. Em relação à taxa de transmissão total, observou-se a transmissão do patógeno em todos os potenciais de inóculo, variando estes valores entre 25% para C2 no potencial P1 sob temperatura de 20 °C e 93% para C2 no potencial P3 sob temperatura de 25 °C.Palavras-chave: Fitopatologia. Patol...

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Section: Resultsmentioning

confidence: 99%

Transmission ofStenocarpella maydisby maize seeds

Siqueira

Barrocas

Machado

et al. 2016

Revista Ciência Agronômica

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“…The water restriction technique was used to obtain seeds contaminated with S. sclerotiorum (isolate C-54-01), using PDA medium + mannitol at -1.0 MPa (Costa et al, 2003). The seeds tested (56 g) were sterilized with 1% sodium hypochlorite and placed on the S. sclerotiorum colonies.…”

Section: Methodsmentioning

confidence: 99%

“…Several products based on Trichoderma are recommended for substrate and seed treatments in the market (Ethur et al, 2007;Mertz et al, 2009). However, studies on seed treatments using biological fungicides are still scarce (Mertz et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Biocontrol of seed pathogens and growth promotion of common bean seedlings by Trichoderma harzianum

Carvalho

Mello

Júnior

et al. 2011

Pesq. agropec. bras.

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-The objective of this work was to evaluate isolates of Trichoderma harzianum regarding biocontrol of common bean seed-borne pathogens, plant growth promotion, and rhizosphere competence. Five isolates of T. harzianum were evaluated and compared with commercial isolate (Ecotrich), Carboxin+Thiram, and an absolute control. Bean seeds of the cultivar Jalo Precoce, contaminated with Aspergillus, Cladosporium, and Sclerotinia sclerotiorum, were microbiolized with antagonists, and seed health tests were carried out. Isolates were evaluated on autoclaved substrate and in field conditions. Ten days after sowing (DAS), plant length was measured. To test rhizosphere competence, isolates were applied in boxes containing autoclaved washed sand, and root colonization was evaluated at 10 DAS, using five plants per box. The most effective isolates in the seed health tests were: CEN287 and CEN289 to control Aspergillus; the commercial isolate to control Cladosporium; and CEN287 and CEN316 to control S. sclerotiorum. Isolates CEN289 and CEN290 promoted bean growth in greenhouse and field. Seed treatment with T. harzianum reduces the incidence of Aspergillus, Cladosporium, and S. sclerotiorum in 'Jalo Precoce' common bean seeds.

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“…phaseoli, empregou-se a técnica de restrição hídrica utilizando-se meio BDA + Manitol a -1,0 MPa (Costa et al, 2003). Após seis dias de cultivo do patógeno nas placas de 15 cm (seis discos/ placa) e constatada a colonização total da superfície do meio, as placas receberam sementes de feijão 'Jalo Precoce'.…”

Section: Infecção E Infestação De Sementes Com F Oxysporumunclassified

Controle de Fusarium oxysporum f.sp. phaseoli in vitro e em sementes, e promoção do crescimento inicial do feijoeiro comum por Trichoderma harzianum

Carvalho¹,

Mello²,

Júnior³

et al. 2011

Trop. plant pathol.

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RESUMOEste trabalho objetivou avaliar seis isolados de Trichoderma harzianum no controle de Fusarium oxysporum f.sp. phaseoli em sementes, e seu efeito no crescimento inicial do feijoeiro comum. Os isolados foram inicialmente confrontados in vitro com o patógeno em testes de cultura pareada e antibiose a 25ºC. Sementes sadias e artificialmente infectadas pelo patógeno foram microbiolizadas com 2 mL de suspensões dos antagonistas (2,5 x 10 8 conídios mL -1 ) para cada 100 g de sementes, em rolo de papel germtest a 20 e 25°C. Os percentuais de incidência do patógeno e de plântulas normais foram avaliados aos sete e nove dias, respectivamente. Em casa de vegetação, os isolados foram aplicados a 5 x 10 9 conídios 500 g -1 de substrato autoclavado, com avaliação do comprimento das raízes e parte aérea das plantas 11 dias após o semeio (12 plantas tratamento -1 ). Todos os isolados apresentaram antagonismo in vitro contra o patógeno. Os isolados CEN202, CEN234, CEN238, CEN240 foram superiores à testemunha no controle de F. oxysporum em sementes, reduzindo entre 35 e 51% da incidência do patógeno e proporcionando entre 73 e 81% de plântulas normais. O comprimento total das plantas com tratamento CEN239 (37,43 cm) foi superior aos demais, cujo comprimento variou entre 27,84 e 33,95 cm. Palavras-chave: Phaseolus vulgaris, controle biológico, patologia de sementes, supressão de crescimento. ABSTRACT Control of Fusarium oxysporum f.sp phaseoli in vitro and on seeds and growth promotion of common bean in early stages by Trichoderma harzianumThe objective of this study was to evaluate the antagonistic capacity of six isolates of Trichoderma harzianum against Fusarium oxysporum f.sp. phaseoli on infected seeds and its effect on the early stages of growth in bean plants. The isolates were also evaluated in dual culture assays and under in vitro antibiosis at 25ºC. Healthy and infected seeds were treated with 2 mL 100 g -1 seeds of the antagonist suspensions (2.5 x 10 8 conidia mL -1 ) for healthy evaluation using blotter method at 20 and 25°C. The percentages of pathogen incidence and normal seedlings were evaluated at seven and nine days, respectively. The isolates were applied at 5 x 10 9 conidia 500 g -1 of sterilized substrate in greenhouse. After 11 days, roots and shoots of the bean plants were measured (12 plants treatment -1 ). Every isolate of T. harzianum presented in vitro antagonism against the pathogen. The strains CEN202, CEN234, CEN238 and CEN240 offered better control of F. oxysporum on seeds than the positive check, causing a reduction between 35 and 51% in pathogen incidence and 73-81% of normal seedling emergence. The total length of the plants treated with CEN239 (37.43 cm) was longer than the other treatments, with length varying between 27.84 and 33.95 cm.

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Inoculação de Fusarium oxysporum f. sp. phaseoli em sementes de feijoeiro através de restrição hídrica

Cited by 41 publications

References 8 publications

Transmission ofStenocarpella maydisby maize seeds

Transmission ofStenocarpella maydisby maize seeds

Biocontrol of seed pathogens and growth promotion of common bean seedlings by Trichoderma harzianum

Controle de Fusarium oxysporum f.sp. phaseoli in vitro e em sementes, e promoção do crescimento inicial do feijoeiro comum por Trichoderma harzianum

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