The antifungal potential of volatile organic compounds (VOCs) produced by actinobacterial strains Streptomyces sp. (ACTB-77) and Amycolatopsis sp. (ACTB-290) from the rhizosphere of Caatinga plants against Colletotrichum musae was investigated. VOCs produced by these microorganisms (axenic and co-culture) were investigated using headspace-solid phase micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). Although no exclusive VOC peaks were observed in the co-culture with ACTB-77, the same experiment involving ACTB-290 yielded five new peaks, including two identified alcohols, suggested as bioreductive products of the corresponding ketones by the fungus. Statistical analysis revealed that co-culture ACTB-77/C. musae has a closer similarity to the fungus than to the actinobacteria, while the co culture ACTB-290/C. musae showed closer similarity to the actinobacteria. These confirmed the more pronounced antifungal activity of the ACTB-290 strain, as observed in the fungus growth inhibition experiments. The antifungal activity of ACTB-290 was associated to its sulfur-containing metabolites, while linalool was suggested as responsible for the ACTB-77 activity.

ABSTRACT The quest for resistance sources against Meloidogyne incognita as a control measure is essential in tomato. Thus, this study aimed to evaluate the reaction of six species of wild solanaceae to M. incognita. The species of wild solanaceae studied were Solanum capsicoides, S. asperolanatum, S. americanum, S. viarum, S. palinacanthum and Nicandra physaloides. Seedlings of wild solanaceae species were transplanted and inoculated with M. incognita. The experiment was performed in a completely randomized design with eight replicates. The analyzed variables were: height of the aerial portion, fresh weight of the aerial portion, fresh weight and length of the root system, gall index, number of galls/g of root, number of egg masses/g of root, number of eggs/g of root and the nematode reproduction factor. Based on gall index and reproduction factor criteria the species S. capsicoides, S. americanum, S. palinacanthum and N. physaloides were classified as resistant against M. incognita. These species also showed a significant increase in height and fresh weight of the aerial portion, length of the root system and fresh weight of the root system. Therefore, these species of wild solanaceae may contribute to the management of M. incognita in future applications.

Abstract Background Populations of yam dry rot nematodes Scutellonema bradys, Pratylenchus coffeae and P. brachyurus can be sustained on weed hosts. Objective Evaluate the reaction of 10 weeds frequently found in Alagoas to P. coffeae under greenhouse conditions. Methods Two experiments were carried out in a completely randomized design, with 11 treatments, constituted of 10 weed species and the control (Dioscorea cayenensis) with eight replications. Plants were inoculated with 2,000 nematode specimens, nematode populations were evaluated in roots and soil 60 days after inoculation and the reproduction factor (RF) defined as RF = final population/initial population was calculated. Results Euphorbia hyssopifolia showed RF=0 and was considered as non-host, whereas Chenopodium album, Amaranthus sp., Panicum maximum, Eleusine indica, Senna occidentalis, Emilia coccinea and Richardia brasiliensis, showed RF<1, being rated as poor hosts. Ricinus communis and Macroptilium lathyroides showed RF>1 only in the second trial and were classified as good hosts. Conclusion Ricinus communis and M. lathyroides are potential sources of nematode inoculum for dry rot disease development.

ABSTRACT Dry rot of yam (Dioscorea spp.) caused by Scutellonema bradys and Pratylenchus spp. has restricted yam production in Brazil. Plant-based products can be useful reducing nematode damages. The objectives of this study were to evaluate the nematostatic and nematicidal in vitro activities of pyroligneous extracts from Cocos nucifera, Syagrus cearensis, S. coronata, and Wodetia bifurcata palms against S. bradys and to evaluate the effect of C. nucifera pyroligneous extract in the treatment of yam tubers infected by S. bradys and Pratylenchus sp. under greenhouse conditions. The pyroligneous extracts obtained at pyrolysis temperatures of 400, 500, 600, and 700 ºC, and at different concentrations, were tested for nematode immobility and mortality in Kline slides. Cocos nucifera pyroligneous extract obtained at 400 °C and 1% concentration was tested on yam tubers, under different immersion periods. Six months after yam planting the nematode populations were evaluated. All pyroligneous extracts inhibited the mobility and caused mortality to S. bradys, however 100% inhibition of both variables was achieved at concentrations varying from 0.75 to 2%, depending on the pyrolysis temperatures. The reproduction factor was reduced in 43% by treating infected yam tubers with pyroligneous extract from C. nucifera.

Resumo Introdução As resinas compostas são alternativas restauradoras, porém sua superfície pode favorecer o acúmulo de biofilme. Objetivo Analisar in vitro a adesão de biofilmes de Streptococcus mutans (UA159) e Candida albicans (ATCC 90028) em superfícies de resinas compostas convencionais e bulk fill. Material e método Foram utilizadas quatro marcas de resinas compostas e bulk fill: Aura Bulk Fill - SDI®; Premisa - Kerr®; Opallis- FGM®, e Filtek bulk fill flow - 3M®. Utilizou-se saliva artificial para formação da película salivar, por 60 min a 37 °C. O inóculo foi padronizado em 1×108 UFC/mL para S. mutans e 1×106 UFC/mL para C. albicans. Os espécimes (n=8/grupo) foram acondicionados em placas de 24 poços, com BHI suplementado com sacarose para as bactérias, e RPMI 1640, para os fungos. A formação do biofilme foi avaliada considerando as unidades formadoras de colônia (UFC/mL).Os dados foram analisados por ANOVA e Tukey (p<0,05). Resultado Para os biofilmes de S. mutans, não houve diferença significativa na contagem de UFC/mL entre os diferentes tipos de resina (p=0,119). Na contagem de UFC/mL para biofilme de Candida, as médias variaram entre 7,78 e 8,34. Houve diferença significativa entre as marcas, especialmente entre as resinas convencionais e bulk fill. Conclusão O presente estudo demonstra que não há diferença na adesão para biofilmes de S. mutans. Porém, há diferença na adesão da C. albicans na superfície de diferentes resinas compostas.

Abstract Introduction Composite resins are restorative alternatives, but their surface may favor the accumulation of biofilm. Objective The aim of this study was to evaluate the in vitro adhesion of Streptococcus mutans (UA159) and Candida albicans (ATCC 90028) biofilms on the surface of conventional and bulk fill composites. Material and method Four brands of conventional and bulk fill composites were used, Aura Bulk Fill - SDI®, Premisa - Kerr®, Opallis- FGM® and Filtek bulk fill flow - 3M®. Artificial saliva was used to form the salivary film for 60 min at 37 ° C. The inoculum was standardized at 1x108 CFU/mL for S. mutans and 1x106 CFU/mL for C. albicans. The specimens (n = 8/group) were placed in 24-well plates, with BHI supplemented with sucrose for bacteria and RPMI 1640 for fungi. The biofilm formation was evaluated considering the colony forming units (CFU/mL). The data were analyzed by ANOVA and Tukey test (p <0.05). Result For S. mutans biofilms, there was no significant difference in the CFU/mL count between the different types of composites (p = 0.119). In the CFU / mL count for C.albicans biofilm, the CFU/mL ranged from 7.78 to 8.34. There was a significant difference between brands for Candida, especially between conventional and bulk fill composites. Conclusion The present study demonstrates that there is no difference in adhesion for S. mutans biofilms. On the other hand, there is a difference in the adhesion of C. albicans to the surface of different composite resins.

A reação de sete genótipos de Coffea arabica a 10 populações de Meloidogyne spp. coletadas principalmente em plantios de café no Brasil e Costa Rica foi avaliada em casa de vegetação. O inóculo consistiu de 10.000 ovos por planta. As avaliações foram realizadas 8 meses após as inoculações considerando-se a massa da matéria fresca das raízes, índices de galhas e massas de ovos, número de ovos por grama de raiz e fator de reprodução (FR). As cultivares Obatã IAC 1669-20, Sarchimor IAC 4361 e Tupi Amarelo IAC 5111 exibiram suscetibilidade às quatro populações brasileiras de M. exigua. Entretanto, cv. Tupi Vermelho IAC 1669-33 mostrou-se resistente (FR=0,7) a uma população de M. exigua proveniente de Lavras, MG, Brasil. A população de M. exigua oriunda de Bom Jesus de Itabapoana, RJ, Brasil foi altamente virulenta à cv. IAPAR 59 (FR= 165,7), portadora do gene de resistência Mex-1 e ao genótipo Paraíso (H 419-5-4-5-2) (FR=396,2). A população de Meloidogyne sp. do cafeeiro, Garça, SP, Brasil, reproduziu-se em baixos níveis (FR = 0,1 - 3,9) sobre todos os genótipos. Todas as cultivares testadas foram suscetíveis a M. incognita e M. paranaensis. A reprodução de M. mayaguensis obtida de goiabeira, PR, Brasil, foi baixa (FR = 0,0-1,6), em todos os genótipos. Entretanto, outra população obtida do cafeeiro na Costa Rica apresentou valores de FR que variaram de 0,8 a 12,4. Os resultados deste trabalho mostraram, pela primeira vez, a capacidade de uma população de M. exigua obtida em campo de superar a resistência conferida pelo gene Mex-1.

The reaction of seven genotypes of Coffea arabica to 10 Meloidogyne spp. populations collected mainly from coffee plantations in Brazil and Costa Rica was evaluated under greenhouse conditions. The inoculum consisted of 10,000 eggs per plant. Evaluations were done 8 months after inoculations considering the root fresh weight, gall and egg mass indices, number of eggs per gram of root and reproduction factor (RF). The cultivars Obatã IAC 1669-20, Sarchimor IAC 4361 and Tupi Amarelo IAC 5111 exhibited susceptibility to the four Brazilian M. exigua populations tested. However, cv. Tupi Vermelho IAC 1669-33 revealed resistance (RF value of 0.7) to the M. exigua population from Lavras, Minas Gerais State, Brazil. A population of M. exigua from Bom Jesus de Itabapoana, Rio de Janeiro State, Brazil, was highly virulent on cv. IAPAR 59 (RF= 165.7), bearing resistance gene Mex-1, and was also virulent on genotype Paraíso (H 419-5-4-5-2) (RF=396.2). A Meloidogyne sp. population on coffee from Garça, São Paulo State, Brazil, reproduced at low rates (RF ranging from 0.1 to 3.9) on all genotypes. All tested cultivars were susceptible to M. incognita and M. paranaensis. M. mayaguensis of guava from Paraná State, Brazil, reproduced at low rates in all coffee genotypes; however, another population of coffee, from Costa Rica, was more aggressive and showed RF value that ranged from 0.8 to 12.4. Results of this study point for the first time to the ability of a naturally occurring M. exigua population to overcome the resistance conferred by the Mex-1 gene.

O presente trabalho teve como objetivo caracterizar nove isolados de Phytophthora sp. obtidos de mandioca (Manihot esculenta), através da morfologia e morfometria das estruturas propagativas e crescimento micelial em diferentes temperaturas e avaliar sua patogenicidade. Os esporângios produzidos em extrato de solo não esterilizado mostraram-se ovóides, não papilados, persistentes, formados em esporangióforos não ramificados ou em simpódio, com dimensões de 24,6 - 57,4 µ x 14,8 - 37,7 µm e relação comprimento/largura de 1,0 - 2,6. Os clamidósporos foram raros. Os oósporos obtidos em cultura monospórica em V8 ágar eram apleuróticos, com 13,1 - 34,4 µm de diâmetro. Oogônios mostraram-se esféricos e mediram 19,7 - 41,0 µm de diâmetro; anterídios anfígenos, com dimensões de 8,2 - 24,6 µm x 8,2 - 19,7 µm. O maior diâmetro das colônias ocorreu a 25 ºC em V8 ágar. Os isolados patogênicos às plantas e raízes destacadas de mandioca inoculados foram identificados como Phytophthora drechsleri.

Nine Phytophthora isolates from cassava (Manihot esculenta) were characterized based on morphology and morphometry of propagative structures, growth at 10, 15, 20, 25, 30 and 35 ºC, and by evaluating its pathogenicity. Sporangia produced on nonsterile soil extract were ovoid, nonpapillate and persistent, formed in a sympodium or unbranched sporangiophores, 24.6 to 57.4 µm long x 14.8 to 37.7 µm wide, and length-breadth ratio was 1.0 - 2.6. Chlamydospores were rarely observed. Oospores produced in single spore culture on V8 agar medium were aplerotic, and 13.1 to 34.4 µm in diameter. Antheridia were amphigynous, measuring 8.2 - 24.6 µ x 8.2 - 19.7 µ ; oogonia ranged from 19.7 to 41.0 µm in diameter. Culture growth was greatest at 25 ºC in V8 agar medium. The isolates that were pathogenic to plants and detached roots of cassava were identified as Phytophthora drechsleri Tucker.

Nove isolados de Phytophthora obtidos da rizosfera de laranjeiras (Citrus sinensis) infetadas, em Alagoas, foram caracterizados com base na morfologia da colônia, morfologia e morfometria das estruturas reprodutivas, e no crescimento em diferentes temperaturas. Todas as culturas apresentaram-se heterotálicas; esporângios papilados, ovóides ou subesféricos, medindo 24,6 - 78,7 µm de comprimento (média=49,1µm) x 16,4 - 49,2 µm de largura (média=33,3 µm), com uma relação comprimento/largura de 1,1 - 2,3 (média=1,5); clamidósporos principalmente terminais, apresentando 13,1 - 45,9 µm de diâmetro (média=27,3 µm). Oogônios globosos, com 14,8 - 34,4 µm de diâmetro (média=26,4 µm) contendo oósporos apleuróticos, medindo 11,5 - 29,5 µm de diâmetro (média=22,7 µm). Anterídios em posição anfígena, medindo 6,6 - 16,7 µm de comprimento (média= 10,6 µm) e 8,2 - 16,7 µm de largura (média=12,0 µm). O maior crescimento micelial ocorreu entre 25 e 30 ºC em meio de cenoura-ágar modificado. Todos os isolados cresceram a 35 ºC e foram patogênicos às mudas de limão (Citrus limonia) 'Cravo' e aos frutos de laranja 'Pêra'. Todos os isolados foram identificados como P. nicotianae (= P. parasitica), pertencentes ao tipo compatível A1.

Nine Phytophthora spp. isolates from the rhizosphere of infected orange (Citrus sinensis) plants in Alagoas were characterized based on colony morphology, morphology and morphometry as well as reproductive structures, and cardinal growth temperatures. All cultures were heterothallic, with papillate, ovoid or subspherical sporangia measuring 24.6 - 78.7 µm long x 16.4 - 49.2 µm wide, average 49.1 x 33.3 µm. The length-breadth ratio was 1.1 - 2.3, average 1.5. Chlamydospores were mostly terminal, 13.1 - 45.9 µm in diameter, average 27.3 µm. Oogonia were globose, 14.8 - 34.4 µm in diameter, average 26.4 µm containing aplerotic oospores 11.5 - 29.5 µm in diameter, average 22.7 µm and amphigynous antheridia 6.6 - 16.7 µm x 8.2 - 16.7 µm (average 10.6 µm x 12.0 µm). The greatest mycelial growth was observed at 25-30 ºC in modified carrot agar medium. All isolates grew at 35 ºC and were pathogenic to lemon (Citrus limonia) cv. Cravo seedlings and ripened fruits of orange (C. sinensis) cv. Pera. The isolates were identified as Phytophthora nicotianae (= P. parasitica) of the A1 mating type.

A new fruit rot disease caused by Sclerotium rolfsii on watermelon (Citrullus lanatus) was observed in the State of Alagoas. The pathogenicity of the fungus was confirmed by artificial inoculations.This is the first report of S. rolfsii causing fruit rot in watermelon in Northeast of Brazil.