Fungal identification in peanuts seeds through multispectral images: Technological advances to enhance sanitary quality.

The sanitary quality of seed is essential in agriculture. This is because pathogenic fungi compromise seed physiological quality and prevent the formation of plants in the field, which causes losses to farmers. Multispectral images technologies coupled with machine learning algorithms can optimize the identification of healthy peanut seeds, greatly improving the sanitary quality. The objective was to verify whether multispectral images technologies and artificial intelligence tools are effective for discriminating pathogenic fungi in tropical peanut seeds. For this purpose, dry peanut seeds infected by fungi (A. flavus, A. niger, Penicillium sp., and Rhizopus sp.) were used to acquire images at different wavelengths (365 to 970 nm). Multispectral markers of peanut seed health quality were found. The incubation period of 216 h was the one that most contributed to discriminating healthy seeds from those containing fungi through multispectral images. Texture (Percent Run), color (CIELab L*) and reflectance (490 nm) were highly effective in discriminating the sanitary quality of peanut seeds. Machine learning algorithms (LDA, MLP, RF, and SVM) demonstrated high accuracy in autonomous detection of seed health status (90 to 100%). Thus, multispectral images coupled with machine learning algorithms are effective for screening peanut seeds with superior sanitary quality.

Colletotrichum truncatum transmission via lima bean seeds

Anthracnose is the primary disease in Phaseolus lunatus cultures, causing severe losses. Inoculation techniques are vital for assessing genotype resistance and control methods at the early stages of seedling development. This study aimed to compare inoculation methods and exposure times of a lima bean seed variety to Colletotrichum truncatum using a completely randomized 4x5 factorial design with five replications. Seed inoculation methods by direct contact with mycelium, mannitol water restrictor, and sucrose water restrictor and immersion in conidia suspension were compared and submitted to substrates containing the developed pathogen or not at exposure times of 0, 36, 60, 84, and 108 hours. Evaluations were made by analyzing the severity, incidence, and disease index for anthracnose and seedling physiological quality under greenhouse conditions. The inoculation method by direct contact with sucrose solute for 36 hours was the most suitable for C. truncatum inoculation in lima bean seeds, providing a higher transmission rate but slightly affecting their physiological parameters. C. truncatum damage to lima bean seed performance increased with longer exposure times, regardless of the inoculation method.

Pantoea ananatis in Oryza sativa in Brazil / Pantoea ananatis em Oryza sativa no Brasil

The state of Santa Catarina is the second-largest producer of rice seeds in Brazil. Research on phytopathogenicbacterias in this crop is scarce and the high frequency of panicle diseases leads to the hypothesis that seeds may be infected by bacteria. This research quantified the incidence of bacteria in the seeds, verified the bacteria viability during the storage period and characterized the associated bacteria. Seeds from the 2018/19 and 2019/20 seasons were analyzed. To check the incidence, the seeds were disinfected, plated on a nutrient agar + fungicide culture medium, and incubated for seven days at 27 °C. To assess viability, every 45 days, three cultivars stored in a processing unit were subjected to the same detection methodology. To characterize, prevalent colonies were isolated on semi-selective culture medium Pantoea genus-specific agar (PGSA), where the ones that showed growth were subjected to deoxyribonucleic acid (DNA) extraction and Polymerase Chain Reaction (PCR), DNA sequencing, and sequence comparison on GenBank. The hypersensitivity reaction (HR) in tobacco was performed using a bacterial suspension of each isolate. All seed samples had an average incidence of 83%. During storage, the seeds maintained stable bacterial viability, with an average incidence of 95% at the beginning of storage and 99% at the end of it. All isolates that grew in PGSA culture medium were identified by molecular characterization with 100% identity with two specimens of Pantoeaananatis and one of them induced RH in tobacco.

O estado de Santa Catarina é o segundo maior produtor de sementes de arroz do Brasil. As pesquisas com bactérias fitopatogênicas nesta cultura são escassas e a alta frequência de doenças da panícula leva à hipótese de que sementes podem estar infectadas por bactérias. O objetivo desta pesquisa foi quantificar a incidência de bactérias nas sementes, verificar a viabilidade das bactérias durante o período de armazenamento e caracterizar as bactérias associadas. Foram analisadas sementes das safras 2018/19 e 2019/20. Para verificar a incidência, as sementes foram desinfestadas, plaqueadas em meio de cultura ágar nutriente + fungicida e incubadas por sete dias a 27 °C. Para avaliar a viabilidade, a cada 45 dias, três cultivares armazenadas em uma unidade de beneficiamento foram submetidas à mesma metodologia de detecção. Para caracterizar, colônias prevalentes foram isoladas em meio de cultura semisseletivo Pantoea genus-specific ágar (PGSA), onde as que apresentaram crescimento foram submetidas à extração do ácido desoxirribonucléico (DNA) e Reação em Cadeia da Polimerase (PCR), sequenciamento do DNA e comparação de sequências no GenBank. A reação de hipersensibilidade (HR) em tabaco foi realizada utilizando uma suspensão bacteriana de cada isolado. Todas as amostras de sementes apresentaram incidência média de 83%. Durante o armazenamento, as sementes mantiveram viabilidade bacteriana estável, com incidência média de 95% no início do armazenamento e 99% ao fim. Todos os isolados que cresceram no meio de cultura PGSA, foram identificados por caracterização molecular com 100% de identidade com dois espécimes de Pantoea ananatis e um deles induziu HR em tabaco.

Pantoea ananatis in Oryza sativa in Brazil / Pantoea ananatis em Oryza sativa no Brasil

ABSTRACT: The state of Santa Catarina is the second-largest producer of rice seeds in Brazil. Research on phytopathogenicbacterias in this crop is scarce and the high frequency of panicle diseases leads to the hypothesis that seeds may be infected by bacteria. This research quantified the incidence of bacteria in the seeds, verified the bacteria viability during the storage period and characterized the associated bacteria. Seeds from the 2018/19 and 2019/20 seasons were analyzed. To check the incidence, the seeds were disinfected, plated on a nutrient agar + fungicide culture medium, and incubated for seven days at 27 °C. To assess viability, every 45 days, three cultivars stored in a processing unit were subjected to the same detection methodology. To characterize, prevalent colonies were isolated on semi-selective culture medium Pantoea genus-specific agar (PGSA), where the ones that showed growth were subjected to deoxyribonucleic acid (DNA) extraction and Polymerase Chain Reaction (PCR), DNA sequencing, and sequence comparison on GenBank. The hypersensitivity reaction (HR) in tobacco was performed using a bacterial suspension of each isolate. All seed samples had an average incidence of 83%. During storage, the seeds maintained stable bacterial viability, with an average incidence of 95% at the beginning of storage and 99% at the end of it. All isolates that grew in PGSA culture medium were identified by molecular characterization with 100% identity with two specimens of Pantoeaananatis and one of them induced RH in tobacco.

RESUMO: O estado de Santa Catarina é o segundo maior produtor de sementes de arroz do Brasil. As pesquisas com bactérias fitopatogênicas nesta cultura são escassas e a alta frequência de doenças da panícula leva à hipótese de que sementes podem estar infectadas por bactérias. O objetivo desta pesquisa foi quantificar a incidência de bactérias nas sementes, verificar a viabilidade das bactérias durante o período de armazenamento e caracterizar as bactérias associadas. Foram analisadas sementes das safras 2018/19 e 2019/20. Para verificar a incidência, as sementes foram desinfestadas, plaqueadas em meio de cultura ágar nutriente + fungicida e incubadas por sete dias a 27 °C. Para avaliar a viabilidade, a cada 45 dias, três cultivares armazenadas em uma unidade de beneficiamento foram submetidas à mesma metodologia de detecção. Para caracterizar, colônias prevalentes foram isoladas em meio de cultura semisseletivo Pantoea genus-specific ágar (PGSA), onde as que apresentaram crescimento foram submetidas à extração do ácido desoxirribonucléico (DNA) e Reação em Cadeia da Polimerase (PCR), sequenciamento do DNA e comparação de sequências no GenBank. A reação de hipersensibilidade (HR) em tabaco foi realizada utilizando uma suspensão bacteriana de cada isolado. Todas as amostras de sementes apresentaram incidência média de 83%. Durante o armazenamento, as sementes mantiveram viabilidade bacteriana estável, com incidência média de 95% no início do armazenamento e 99% ao fim. Todos os isolados que cresceram no meio de cultura PGSA, foram identificados por caracterização molecular com 100% de identidade com dois espécimes de Pantoea ananatis e um deles induziu HR em tabaco.

Plant extracts in agriculture and their applications in the treatment of seeds / Extratos vegetais na agricultura e suas aplicações no tratamento de sementes

The harmful effects caused by the use of toxic substances in agriculture have led to the development of alternative solutions, and researchers have focused on understanding the effectiveness and potential of plant extracts in agriculture. The aim of this systematic review was to understand the situation of research and scientific dissemination, as well as how current science has approached the use of plant extracts in agriculture, especially in seed applications. There is potential on the use of plant extracts in agriculture, demonstrated by a high number of publications over the last ten years, especially in the years 2018, 2019 and 2020, and Brazil stands out as the main country on this research area. Control of phytopathogenic microorganisms, insect control, biostimulant effect, resistance induction and herbicide effect have been the main themes explored for use in agriculture. The direct application of plant extracts is centered on plants and seeds, being this latter mainly focused on the control of phytopathogenic organisms and biostimulating effect.

Em resposta aos efeitos nocivos da utilização de substâncias toxicas na agricultura, a ciência tem avançado no desenvolvimento de soluções alternativas, visando compreender a eficácia e o potencial de extratos vegetais na agricultura. Objetivou-se com esta revisão sistematizada compreender a situação da pesquisa e divulgação científica, bem como a maneira que a ciência atual tem abordado o uso de extratos vegetais na agricultura, especialmente na aplicação em sementes. O uso de extratos vegetais na agricultura tem potencial demonstrado pelo elevado número de publicações nos últimos dez anos, com destaque para os anos de 2018, 2019 e 2020, sendo o Brasil o país de maior produção de trabalhos voltados à essa área de estudo. Os temas controle de microrganismos fitopatogênicos, controle de insetos, efeito bioestimulante, indução de resistência e efeito herbicida tem sido os principais temas explorados para uso na agricultura. A aplicação de extratos vegetais é centrada principalmente em organismos fitopatogênicos associados a plantas e sementes, sendo que, para a aplicação em sementes, o foco está no controle de organismos fitopatogênicos e efeito de promoção de crescimento.

Botanical and chemical fungicides in the treatment of commercial seeds of Brachiaria brizantha and Panicum maximum.

Brazil is the largest producer, consumer, and exporter of forage seeds in the world. However, the high incidence of pathogens threatens the seed production system, resulting in decreases in production and quality. Currently, the emphasis has been placed on the use of alternative products as a way of maintaining productivity and environmental sustainability. Thus, the objective of this study was to evaluate the mycoflora associated with the commercial seeds of Brachiaria brizantha and Panicum maximum treated with chemical and alternative fungicide. To test with chemical and alternative treatments, seeds were subjected to fluazinam + thiophanate-methyl, fludioxonil + metalaxyl-M, noni essential oil, rosemary pepper essential oil, sulfuric acid. There was also an untreated control. The most efficient products in the control of incident fungi were, in decreasing order, fluazinam + thiophanate-methyl, fludioxonil + metalaxyl-M, noni essential oil, rosemary pepper essential oil, and sulfuric acid. Fungicides mainly controlled the genera Alternaria, Aspergillus, Bipolaris, Chaetomium, Cladosporium, Colletotrichum, Curvularia, Fusarium, Penicillium, Phoma and Rhizopus. Essential oils showed positive effects in controlling Bipolaris, Curvularia, and Fusarium. Sulfuric acid reduced the incidence of Bipolaris, Colletotrichum, Curvularia, Fusarium, Phoma, and Rhizopus. Seed treatment is one of the promising strategies for obtaining seeds of a healthy quality. As a result, the fungicides and botanical components listed above were promising in reducing fungi associated with forage seeds and can be used for seed treatments and in the development of new products with a natural base through essential oils.

Fungi on irrigated rice seeds produced in the pre-germinated system in the Alto Vale do Itajaí region, Santa Catarina state, Brazil / Fungos em sementes de arroz irrigado produzidas no sistema pré-germinado na região do Alto Vale do Itajaí, estado de Santa Catarina, Brasil

The aim of this research was to identify and quantify fungi infecting irrigated rice seeds produced in the 2015/16, 2016/17 and 2017/18 harvests in the pre-germinated system in the Alto Vale do Itajaí Region, Santa Catarina State, Brazil. A total of 479 lots of eight cultivars were analyzed. Seeds were disinfected and sown in potato-sucrose-agar culture medium with incubation for seven days at 25ºC ± 2ºC and photoperiod of 12 hours. The main fungus detected in the three crops season was Microdochium albescens with 54.9% of average incidence, followed by Alternaria padwikii (7.7%) and Bipolaris oryzae (3.3%).(AU)

O objetivo deste trabalho foi identificar e quantificar fungos infectando sementes de arroz irrigado, produzidas nas safras 2015/16, 2016/17 e 2017/18, no sistema pré-germinado na região do Alto Vale do Itajaí, estado de Santa Catarina. Foram analisados 479 lotes de oito cultivares, sendo as sementes desinfestadas e semeadas em meio de cultura de batata-sacarose-ágar com incubação por sete dias a 25ºC ± 2 ºC e fotoperíodo de 12 horas. O principal fungo detectado nas três safras foi Microdochium albescens com 54,9% de incidência média, seguido de Alternaria padwikii (7,7%) e Bipolaris oryzae (3,3%).(AU)

Fungi on irrigated rice seeds produced in the pre-germinated system in the Alto Vale do Itajaí region, Santa Catarina state, Brazil / Fungos em sementes de arroz irrigado produzidas no sistema pré-germinado na região do Alto Vale do Itajaí, estado de Santa Catarina, Brasil

ABSTRACT: The aim of this research was to identify and quantify fungi infecting irrigated rice seeds produced in the 2015/16, 2016/17 and 2017/18 harvests in the pre-germinated system in the Alto Vale do Itajaí Region, Santa Catarina State, Brazil. A total of 479 lots of eight cultivars were analyzed. Seeds were disinfected and sown in potato-sucrose-agar culture medium with incubation for seven days at 25ºC ± 2ºC and photoperiod of 12 hours. The main fungus detected in the three crops season was Microdochium albescens with 54.9% of average incidence, followed by Alternaria padwikii (7.7%) and Bipolaris oryzae (3.3%).

RESUMO: O objetivo deste trabalho foi identificar e quantificar fungos infectando sementes de arroz irrigado, produzidas nas safras 2015/16, 2016/17 e 2017/18, no sistema pré-germinado na região do Alto Vale do Itajaí, estado de Santa Catarina. Foram analisados 479 lotes de oito cultivares, sendo as sementes desinfestadas e semeadas em meio de cultura de batata-sacarose-ágar com incubação por sete dias a 25ºC ± 2 ºC e fotoperíodo de 12 horas. O principal fungo detectado nas três safras foi Microdochium albescens com 54,9% de incidência média, seguido de Alternaria padwikii (7,7%) e Bipolaris oryzae (3,3%).

Influence of physiological and health quality on the vigor of cucumber seeds / Influência da qualidade fisiológica e sanitária no vigor de sementes de pepino

The physiological performance of seeds is related to their physiological quality and seed vigor, while their health quality may interfere with germination and early seedling establishment in the field due to the interaction of microorganisms associated with seeds. The study aimed to evaluate the physiological performance and health quality of cucumber seeds and to verify the relationship between these attributes. The physiological quality of cucumber seeds was evaluated by standard germination tests, first count of germination, controlled deterioration test, electrical conductivity test, seedling emergence, emergence speed index, and traditional accelerated aging and aging modified with saline for 48, 72, and 96 h. The health quality of cucumber seed lots was evaluated by blotter test. Stratification of cucumber seed lots by seedling emergence was similar to seedling emergence by controlled deterioration test, first count of germination, and electrical conductivity results. The cucumber seed lots evaluated showed high germination rates; however, lots 1 and 3 had a better performance in vigor tests than lots 2 and 4. Fungi detected in the blotter test were Alternaria sp., Aspergillus sp., Cladosporium sp., and Penicillium sp. Seed lots 2 and 4 had low vigor evaluated by seedling emergence and controlled deterioration, and showed a higher incidence of Penicillium sp. in the evaluation of health quality of seeds. The incidence of Penicillium sp. may negatively affect the vigor of cucumber seeds evaluated by seedling emergence and by controlled deterioration test.(AU)

O desempenho fisiológico de sementes diz respeito à sua qualidade fisiológica e vigor, enquanto a qualidade sanitária pode interferir na germinação e estabelecimento inicial de plântulas no campo devido à interação dos micro-organismos associados às sementes. O trabalho teve por objetivo avaliar o desempenho fisiológico e a qualidade sanitária de sementes de pepino e verificar a relação entre esses atributos. A qualidade fisiológica de sementes de pepino foi avaliada pelos testes de germinação, primeira contagem de germinação, deterioração controlada, condutividade elétrica, emergência de plântulas, índice de velocidade de emergência e envelhecimento acelerado tradicional e modificado com solução salina por 48, 72 e 96 horas. A qualidade sanitária das sementes foi avaliada pelo método do papel-filtro. A estratificação de lotes de sementes de pepino ocorreu de maneira similar à emergência de plântulas pelos testes de deterioração controlada, primeira contagem da germinação e condutividade elétrica. Os lotes de sementes de pepino avaliados apresentaram alto percentual de germinação; no entanto, os lotes 1 e 3 apresentaram melhor desempenho nos testes de vigor que os lotes 2 e 4. Os fungos detectados no teste do papel-filtro foram Alternaria sp., Aspergillus sp., Cladosporium sp. e Penicillium sp. Os lotes 2 e 4 de menor vigor avaliados pelos testes de emergência de plântulas e de deterioração controlada foram os mesmos que apresentaram maior incidência de Penicillium sp. na avaliação da qualidade sanitária das sementes. A incidência de Penicillium sp. pode influenciar negativamente o vigor de sementes de pepino avaliado pela emergência de plântulas pelo teste de deterioração controlada.(AU)

Influence of physiological and health quality on the vigor of cucumber seeds / Influência da qualidade fisiológica e sanitária no vigor de sementes de pepino

The physiological performance of seeds is related to their physiological quality and seed vigor, while their health quality may interfere with germination and early seedling establishment in the field due to the interaction of microorganisms associated with seeds. The study aimed to evaluate the physiological performance and health quality of cucumber seeds and to verify the relationship between these attributes. The physiological quality of cucumber seeds was evaluated by standard germination tests, first count of germination, controlled deterioration test, electrical conductivity test, seedling emergence, emergence speed index, and traditional accelerated aging and aging modified with saline for 48, 72, and 96 h. The health quality of cucumber seed lots was evaluated by blotter test. Stratification of cucumber seed lots by seedling emergence was similar to seedling emergence by controlled deterioration test, first count of germination, and electrical conductivity results. The cucumber seed lots evaluated showed high germination rates; however, lots 1 and 3 had a better performance in vigor tests than lots 2 and 4. Fungi detected in the blotter test were Alternaria sp., Aspergillus sp., Cladosporium sp., and Penicillium sp. Seed lots 2 and 4 had low vigor evaluated by seedling emergence and controlled deterioration, and showed a higher incidence of Penicillium sp. in the evaluation of health quality of seeds. The incidence of Penicillium sp. may negatively affect the vigor of cucumber seeds evaluated by seedling emergence and by controlled deterioration test.(AU)

O desempenho fisiológico de sementes diz respeito à sua qualidade fisiológica e vigor, enquanto a qualidade sanitária pode interferir na germinação e estabelecimento inicial de plântulas no campo devido à interação dos micro-organismos associados às sementes. O trabalho teve por objetivo avaliar o desempenho fisiológico e a qualidade sanitária de sementes de pepino e verificar a relação entre esses atributos. A qualidade fisiológica de sementes de pepino foi avaliada pelos testes de germinação, primeira contagem de germinação, deterioração controlada, condutividade elétrica, emergência de plântulas, índice de velocidade de emergência e envelhecimento acelerado tradicional e modificado com solução salina por 48, 72 e 96 horas. A qualidade sanitária das sementes foi avaliada pelo método do papel-filtro. A estratificação de lotes de sementes de pepino ocorreu de maneira similar à emergência de plântulas pelos testes de deterioração controlada, primeira contagem da germinação e condutividade elétrica. Os lotes de sementes de pepino avaliados apresentaram alto percentual de germinação; no entanto, os lotes 1 e 3 apresentaram melhor desempenho nos testes de vigor que os lotes 2 e 4. Os fungos detectados no teste do papel-filtro foram Alternaria sp., Aspergillus sp., Cladosporium sp. e Penicillium sp. Os lotes 2 e 4 de menor vigor avaliados pelos testes de emergência de plântulas e de deterioração controlada foram os mesmos que apresentaram maior incidência de Penicillium sp. na avaliação da qualidade sanitária das sementes. A incidência de Penicillium sp. pode influenciar negativamente o vigor de sementes de pepino avaliado pela emergência de plântulas pelo teste de deterioração controlada.(AU)