Secagem por spray drying de extrato de folha de café

The coffee leaf extract formulation has been used as resistance inductor in plants and to control phytopathologies. This work aimed to study the influence of spray drying process variables with the use of maltodextrin as carrier on the characteristics of the powder, by using a central composite rotational design (CCRD). The independent variables were maltodextrin concentration (X1, 0 to 30 % w/v), coffee leaf extract concentration (X2, 2 to 32 % w/v), inlet air temperature (X3, 180 to 250 °C) and air flow rate (X4, 3.5 to 5.5 m3min-1). The response variables were collection efficiency (h), moisture content (MC), phenolic compounds content (Ph), soluble solids (S) content, wettability (We) and particle size (Me). The results showed that the combination of a higher concentrations of coffee leaf extract (X2) (32%) and lower inlet air temperatures (X3) (180°C) make the best drying performance. This process condition lead to a powder with higher Ph, S, We, Me and lower MC. Therefore, the use of high air flow rates (X4) increase the collection efficiency (h) of process and the use of low maltodextrin concentration (X1) lead to better preservation of phenolic compounds content (Ph) on coffee leaf extract powdered.A formulação de extrato de folhas de café foi utilizada como indutor de resistência em plantas e no controle de fitopatologias. Objetivou-se, neste trabalho,estudar a influência das variáveis do processo de secagem por spray drying, com o uso de maltodextrina como agente carreador, nas características do pó, através do uso de um delineamento central composto rotacional (DCCR). As variáveis independentes foram a concentração de maltodextrina (X1, 0 a 30 % p/v), concentração de extrato de folhas de café (X2, 2 a 32 % p/v), temperatura de entrada do ar (X3, 180 a 250 °C) e taxa de fluxo de ar (X4, 3.5 a 5.5 m3min-1). As variáveis resposta foram eficiência de coleta , conteúdo de umidade (MC), conteúdo de compostos fenólicos (Ph), conteúdo de sólidos solúveis (S), molhabilidade (We) e tamanho da partícula (Me). Os resultados mostraram que a combinação de altas concentrações de extrato de folha de café (X2) (32%) e baixas temperaturas de entrada de ar (X3) (180°C) proporcionaram as melhores performances de secagem. Essa condição de processo produz pós com maiores Ph, S, We, Me e menores MC. Além disso, o uso de altas taxas de fluxo de ar (X4) aumentam a eficiência de coleta do processo e o uso de baixas concentrações de maltodextrina (X1) promovem uma melhor preservação dos compostos fenólicos (Ph) nos pós de extrato de folha de café

Protective effect and expression of defense-related ESTs induced by acibenzolar-S-methyl and a phosphorylated mannan oligosaccharide-based product against Moniliophthora perniciosa in Theobroma cacao

Witches’ broom disease (WBD), caused by the fungus Moniliophthora perniciosa, is one of the main diseases in cocoa (Theobroma cacao) and has caused severe economic losses. Integrated disease management has been the focus for its control and therefore, the identification of new inducers of plant resistance is desirable. Thus, the goal of this work was to evaluate two potential inducers of resistance against WBD. A phosphorylated mannan oligosaccharide-based product (PMO) and acibenzolar S-methyl (ASM) were tested on M. perniciosa inoculated seedlings and in field experiments and showed a reduction on the incidence of WBD. The expression of two defense-related expressed sequence tags (ESTs) in cocoa, coding for peroxidase (Pox) and chitinase (Chi), were accessed by qPCR. Both products induced the expression of the Pox defense-related EST. In general, ASM induced the expression of chitinase (Chi) and peroxidase (Pox) in earlier time-points than PMO. However, PMO provided long-lasting and higher levels of expression. Chi expression was triggered in the time-points succeeding the spraying but was very low. On the other hand, peaks of Pox transcripts were detected in later time-points for both inducers. ASM and PMO modes of action might be explained, at least partially, by the overexpression of defense-related ESTs.Keywords: Cocoa, witches’ broom disease, disease control, peroxidase, chitinase, induced resistance, elicitors, quantitative reverse transcriptase PCR (qRT-PCR)African Journal of Biotechnology Vol. 12(12), pp. 1311-131

Potential of rust-resistant arabica coffee cultivars for specialty coffee production

Rust is the main disease affecting Coffea arabica, the most economically important coffee species. The objective of this study was to analyze C. arabica cultivars with different levels of rust resistance, including bean size, raw bean appearance, final sensory scores (FSS), and aroma and taste nuances of the coffee cup. The experiment was designed in randomized blocks (RBD) with three replications and 20 treatments (cultivars), totaling 60 experimental plots. The rust-susceptible cultivars IPR 100, Rubi MG 1192, and Topázio MG 1190 were compared with 17 rust-resistant cultivars. Cultivars IPR 103, MGS Aranãs, and Saíra II presented the highest percentages of high sieves, highest scores of raw bean appearance, and low percentages of mocha-type beans. All cultivars had FSS above 82 and were classified as specialty coffees. The cultivars with the highest FSS (Arara and Catiguá MG2) showed a greater diversity of coffee cup aroma and flavor nuances. Rust-resistant Arabica coffee cultivars are promising for the physical quality of beans and have potential for the specialty coffee market

Activation of defence responses on cocoa against Verticillium wilt by natural extracts and acibenzolar-S-methyl

O objetivo deste trabalho foi avaliar o potencial de extratos fúngicos e vegetais na redução da murcha-de-verticílio do cacaueiro, as atividades da peroxidase e polifenoloxidase e o conteúdo de lignina. Mudas de cacaueiro foram pulverizadas com filtrado de micélio de Rhizopus sp. (FMR), quitosana de Rhizopus sp. (QMR) e Trichoderma sp. (QMT), extratos de casca in natura e seca de maracujá, extrato metanólico de casca seca de frutos de maracujá (MMS) e acibenzolar-S-metil (ASM – 0.2 mg mL-1) e sete dias depois, submetidas à inoculação de Verticillium dahliae. O ASM reduziu a murcha-de-verticílio em 38,0%, seguido dos extratos FMR, QMT, MMS e QMR, que apresentaram reduções em 22,8, 20,1, 19,2 e 15,7%, respectivamente, em relação à testemunha. Plantas pulverizadas com ASM ou FMR seguidas de inoculação apresentaram aumento da atividade de peroxidase aos oito dias após a pulverização, comparadas às respectivas testemunhas, com pico aos 18 dias após a pulverização. ASM e FMR aumentaram a atividade de polifenoloxidase aos quatro dias após a pulverização. Maiores concentrações de lignina foram obtidas em plantas tratadas com FMR e FMR seguido de inoculação. FMR é um potencial indutor de resistência para manejo de murcha-de-verticílio em cacaueiro.The objective of this work was to assess the potential of fungal and plant extracts on the reduction of Verticillium wilt of cocoa, the activities of the enzymes peroxidase and polyphenoloxidase, as well as the lignin content. Seedlings of cocoa were sprayed with the mycelial filtrate of Rhizopus sp. (FMR), chitosan from Rhizopus sp. (QMR) and Trichoderma sp. (QMT), extracts of fresh and dry passion fruit peel, methanolic extract from dry passion fruit peel (MMS) and acibenzolar-S-methyl (ASM – 0.2 mg mL-1) and, inoculed with Verticillium dahliae, seven days later. ASM reduced the cocoa Verticillium wilt in 38.0%. The extract FMR, QMT, MMS and QMR presented as well reductions of 22.8, 20.1, 19.2 and 15.7%, respectively, in comparison with the control. Plants sprayed with ASM or FMR followed by inoculation presented increase of peroxidase activity at the 8th day after spraying, compared to the respective controls, with peak at the 18th day after spraying. ASM and FMR increased polyphenoloxidase activity at the 4th day after spraying. Higher lignin concentrations were obtained in plants treated with FMR and FMR following by inoculation. FMR may constitute a potential resistance inducer for the management of the Verticillium wilt of cocoa

Chitinase and beta-1,3-glucanase activities after the elicitation of tomato defenses against bacterial spot

O objetivo deste trabalho foi avaliar a influência de eliciadores biológicos e químicos sobre as atividades de duas proteínas relacionadas à patogênese (PR), quitinase e beta-1,3-glucanase, em folhas de tomateiro, e avaliar o potencial desses eliciadores na redução do progresso da mancha-foliar causada por Xanthomonas campestris pv. vesicatoria. Plantas de tomateiro da cultivar Santa Cruz Kada foram pulverizadas com: acibenzolar-S-metil (ASM; 0,2 g  L-1); formulação biológica proveniente de biomassa cítrica, denominada Ecolife (5 mL L-1); suspensão de quitosana (MCp; 200 g L-1 ), proveniente de micélio de Crinipellis perniciosa; extrato aquoso de ramos de lobeira (Solanum lycocarpum) infectados por C. perniciosa (VLA; 300 g L-1 ). As plantas foram desafiadas com um isolado virulento da bactéria, quatro dias depois das pulverizações. Plantas pulverizadas com extratos biológicos mostraram redução da mancha-bacteriana. ASM proporcionou 49,3% de proteção, e foi igual à MCp e Ecolife e superior ao VLA. Este último não diferiu significativamente de MCp e Ecolife. Observou-se maior atividade das duas enzimas nas plantas tratadas, principalmente nas primeiras horas após as pulverizações.The objective of this work was to assess the influence of foliar application of resistance inducers and the activation of plant pathogenesis-related (PR) proteins, chitinases and beta-1,3-glucanases, against Xanthomonas campestris pv. vesicatoria, and evaluate the potential of these elicitors on the reduction of bacterial leaf spot. Tomato plants of the cultivar Santa Cruz Kada were sprayed with: acibenzolar-S-methyl (0.2 g L-1 ASM); Ecolife, a biological formulation based on citric biomass (5 mL L-1); chitosan suspension from Crinipellis perniciosa mycelium (MCp; 200 g L-1); an aqueous extract from branches of lobeira (Solanum lycocarpum) infected with C. perniciosa (VLA; 300 g L-1). Plants were challenged with a virulent bacterial strain four days after spraying. Plants sprayed with the tested substances showed reduction of bacterial spot. ASM provided 49.3% protection, and was equal to MCp and Ecolife, and superior to VLA. VLA treatment did not differ statistically from MCp and Ecolife. Increases of beta-1,3-glucanase and chitinase activities were observed in treated plants at the first hour after spraying

Alternative products for the protection of vine against downy mildew

O objetivo deste trabalho foi avaliar a eficiência de produtos alternativos na proteção da videira (Vitis vinifera) contra o míldio (Plasmopara viticola), bem como determinar a influência desses produtos na qualidade dos frutos da cultivar Merlot. Para o controle da doença, foram utilizados produtos à base de extratos vegetais, manano-oligossacarídeos fosforilados, fosfitos e acibenzolar-S-metil, além de fungicidas tradicionais. A intensidade do míldio em folhas e cachos, a produtividade, o número total de cachos por parcela, o peso médio do cacho e baga e as características analíticas do mosto foram avaliados nas safras de 2007/2008 e 2008/2009. Os fosfitos proporcionaram proteção contra o míldio da videira, com produtividade semelhante à do tratamento com fungicidas tradicionais. Os tratamentos baseados em manano-oligossacarídeos fosforilados, acibenzolar-S-metil e extratos vegetais não apresentaram controle eficiente do míldio. Os produtos alternativos testados não influenciam a qualidade analítica dos frutos, mas proporcionam, em geral, peso médio de cachos e de bagas menor que o do tratamento com fungicidas.The objective of this work was to evaluate the efficiency of alternative products for the protection of vine (Vitis vinifera) against downy mildew (Plasmopara viticola), and to determine the influence of these products on the quality of Merlot cultivar grapes. Products based on plant extracts, phosphorylated mannanoligosaccharides, phosphites and acibenzolar-S-methyl, besides traditional fungicides, were used for the disease control. The intensity of downy mildew on leaves and bunches, productivity, total number of bunches per plot, average weight of bunch and berry and analytical characteristics of grapes were assessed during the 2007/2008 and 2008/2009 seasons. Phosphites provided protection against downy mildew, and the yield was similar that of to the treatment with traditional fungicides. Treatments based on phosphorylated mannanoligosaccharides, acibenzolar-S-methyl and plant extracts showed no effective control of downy mildew. The alternative products tested do not influence the analytical quality of the grapes, but generally provide lower average weight of bunches and berries than the treatment with fungicides

Potassium phosphite on the control of downy mildew of grapevine and physicochemical characteristics of Merlot grapes

O objetivo deste trabalho foi avaliar o efeito de doses crescentes de duas formulações de fosfito de potássio, sobre a severidade do míldio da videira, produtividade e características físico‑químicas de uvas Merlot. Foram avaliadas duas formulações de fosfito de potássio (Phi A e B), nas doses 0, 1,2, 2,5, 3,7 e 5,0 g L-1 de P2O5, comparadas com um fertilizante foliar e fungicidas, nas safras de 2009/2010 e 2010/2011. Observou-se efeito linear das doses de fosfito sobre a redução da severidade do míldio, nas duas safras. A maior dose de Phi A proporcionou controle médio de 60,5% e a de Phi B de 57,7%, semelhante ao controle pelos fungicidas (64,3%) e pelo fertilizante foliar (53,3%). Na primeira safra, Phi B proporcionou maior produtividade e, na segunda, não diferiu do tratamento com o fungicida. Os tratamentos somente produziram efeito sobre teor de sólidos solúveis, pH e acidez total titulável do mosto na segunda safra. Phi B e fungicidas proporcionaram os maiores teores de compostos fenólicos solúveis totais das cascas, porém, não produziram efeito sobre os teores de antocianinas. A aplicação de fosfito de potássio aumenta o teor de sólidos solúveis totais e o pH, reduz a acidez total titulável das bagas, não afeta o teor de antocianinas e é alternativa eficaz para o controle do míldio da videira, com resposta similar à proporcionada por fungicidas.The objective of this work was to evaluate the effect of increasing doses of two formulations of potassium phosphite, on the severity of downy mildew of grapevine, yield and on physicochemical characteristics of Merlot grapes. Two formulations of potassium phosphite (Phi A and B) were evaluated at the doses 0, 1.2, 2.5, 3.7 and 5.0 g L-1 of P2O5, in comparison with a foliar fertilizer and fungicides, during the 2009/2010 and 2010/2011 crop seasons. There was a linear effect of phosphite doses on the reduction of the downy mildew severity, in the two crop seasons. The Phi A highest dose provided an average control of 60.5%, and Phi B, 57.7%, similar to the control by the fungicides (64.3%) and fertilizer (53.3%). In the first harvest, Phi B provided a greater productivity, while, in the second, it did not differ from the treatment with fungicides. Treatments only affected soluble solids, pH and total acidity of the grape must in the second season. Phi B and fungicides provided the highest levels of total soluble phenolic compounds at the grape peel, however, had no effect on the levels of anthocyanins. Potassium phosphite application increases total soluble solids and pH, reduces total titratable acidity of the berries, does not affect anthocyanin contents, and it is an effective alternative for the control of downy mildew, with response similar to that of fungicides

Resistance induction to root rot in papaya by biotic and abiotic elicitors

O objetivo deste trabalho foi avaliar o potencial do uso de indutores de resistência bióticos e abióticos na redução da podridão radicular em mamoeiro. Mudas de mamoeiro foram pulverizadas com os fungicidas fosetil-Al, metalaxil e Mancozeb (2 g), com os indutores abióticos fosfito de potássio (2,5 e 5 mL), ácido salicílico 0,15 e 0,30%, Reforce (indutor comercial) + ácido salicílico a 5%, a (0,15 e 0,30 g L-1), e com o indutor biótico Saccharomyces cerevisiae (3 e 6 mL L-1), três e seis dias antes da pulverização de 1 mL de suspensão de 105 zoósporos mL-1 de Phytophthora palmivora. Todos os tratamentos tiveram efeito no controle da podridão de raízes em relação à testemunha, com exceção do Reforce + ácido salicílico a 5% (3 mL L-1), seis dias antes da inoculação. Os tratamentos com ASM, com exceção da dosagem 0,15 g L-1 seis dias antes da inoculação, apresentaram resultados similares aos dos fungicidas metalaxil e Mancozeb. Plantas pulverizadas com ASM apresentaram aumento de atividade da peroxidase e beta-1,3-glucanase e maior concentração de lignina que a testemunha. No entanto, esses tratamentos não tiverem efeito sobre a atividade da quitinase. O ASM é um potencial indutor de resistência a P. palmivora em mamoeiro.The objective of this work was to evaluate the potential use of biotic and abiotic elicitors of resistance in the reduction of root rot in papaya. Papaya seedlings were sprayed with the fosetil-Al and metalaxyl and Mancozeb (2 g L-1) fungicides, with the potassium phosphite (2.5 and 5 mL L-1), salicylic acid 0.15 e 0.30%, Reforce (commercial product) + salicylic acid 5%, acibenzolar-S-methyl (ASM) (0.15 and 0.30 g L-1) abiotic elicitors, and with the Saccharomyces cerevisiae (3 and 6 mL L-1) biotic elicitor, applied three and six days before the inoculation with 1 mL of 105 zoospores mL-1 suspension of Phytophthora palmivora. All treatments were effective in controlling papaya root rot in comparison with the control, except for the Reforce + salicylic acid 5% (3 mL L-1) treatment applied six days before inoculation. The treatments with the ASM elicitor, except for the 0.15 g L-1 dosage applied six days before inoculation, had control levels similar to those of the metalaxyl and Mancozeb fungicide. Plants sprayed with ASM presented increased peroxidase and beta-1,3-glucanase activity and higher lignin content than the control. However, these treatments had no effect on chitinase activity. ASM is a potential elicitor for resistance to P. palmivora in papaya

Indução de resistência do mamoeiro à podridão radicular por indutores bióticos e abióticos

The objective of this work was to evaluate the potential use of biotic and abiotic elicitors of resistance in the reduction of root rot in papaya. Papaya seedlings were sprayed with the fosetil-Al and metalaxyl and Mancozeb (2 g L-1) fungicides, with the potassium phosphite (2.5 and 5 mL L-1), salicylic acid 0.15 e 0.30%, Reforce (commercial product) + salicylic acid 5%, acibenzolar-S-methyl (ASM) (0.15 and 0.30 g L-1) abiotic elicitors, and with the Saccharomyces cerevisiae (3 and 6 mL L-1) biotic elicitor, applied three and six days before the inoculation with 1 mL of 105 zoospores mL-1 suspension of Phytophthora palmivora. All treatments were effective in controlling papaya root rot in comparison with the control, except for the Reforce + salicylic acid 5% (3 mL L-1) treatment applied six days before inoculation. The treatments with the ASM elicitor, except for the 0.15 g L-1 dosage applied six days before inoculation, had control levels similar to those of the metalaxyl and Mancozeb fungicide. Plants sprayed with ASM presented increased peroxidase and beta-1,3-glucanase activity and higher lignin content than the control. However, these treatments had no effect on chitinase activity. ASM is a potential elicitor for resistance to P. palmivora in papaya.O objetivo deste trabalho foi avaliar o potencial do uso de indutores de resistência bióticos e abióticos na redução da podridão radicular em mamoeiro. Mudas de mamoeiro foram pulverizadas com os fungicidas fosetil-Al, metalaxil e Mancozeb (2 g), com os indutores abióticos fosfito de potássio (2,5 e 5 mL), ácido salicílico 0,15 e 0,30%, Reforce (indutor comercial) + ácido salicílico a 5%, a (0,15 e 0,30 g L-1), e com o indutor biótico Saccharomyces cerevisiae (3 e 6 mL L-1), três e seis dias antes da pulverização de 1 mL de suspensão de 105 zoósporos mL-1 de Phytophthora palmivora. Todos os tratamentos tiveram efeito no controle da podridão de raízes em relação à testemunha, com exceção do Reforce + ácido salicílico a 5% (3 mL L-1), seis dias antes da inoculação. Os tratamentos com ASM, com exceção da dosagem 0,15 g L-1 seis dias antes da inoculação, apresentaram resultados similares aos dos fungicidas metalaxil e Mancozeb. Plantas pulverizadas com ASM apresentaram aumento de atividade da peroxidase e beta-1,3-glucanase e maior concentração de lignina que a testemunha. No entanto, esses tratamentos não tiverem efeito sobre a atividade da quitinase. O ASM é um potencial indutor de resistência a P. palmivora em mamoeiro