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Copyright of Revista Ciência Agronômica is the property of Revista Ciencia Agronomica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tendo em vista a importância dos óleos essenciais, objetivou-se, com este trabalho, avaliar a atividade antioxidante e os efeitos fungitóxicos do óleo essencial de capim-limão e do seu constituinte majoritário citral sobre a inibição micelial dos fitopatógenos Fusarium oxysporum cubense, Colletotrichum gloeosporioides, Bipolaris sp. e Alternaria alternata. A atividade antioxidante foi realizada, empregando os métodos de redução do radical livre DPPH e o ensaio de oxidação do sistema b-caroteno/ácido linoléico. Para cada metodologia, utilizou-se o delineamento inteiramente casualizado em esquema fatorial de 4 x 5, sendo quatro compostos (óleo essencial, citral, timol e α-tocoferol) e cinco concentrações (5; 10; 25; 50 e 100 µg L-1), com três repetições Os ensaios para verificação das atividades fungitóxicas foram realizados aplicando o teste de fumigação in vitro sobre a inibição micelial dos fungos fitopatogênicos estudados. Os tratamentos foram dispostos de forma inteiramente casualizada, com três repetições e em esquema fatorial com arranjo variável entre os fitopatógenos. O óleo essencial e o citral apresentaram pequena atividade antioxidante perante a metodologia que avalia a redução do radical estável DPPH, no entanto, perante a metodologia que emprega o sistema emulsificado β-caroteno/ácido linoléico estes compostos apresentaram atividades antioxidantes significativas. Nas atividades fungitóxicas, o óleo essencial e o citral apresentaram uma maior atividade sobre o fitopatógeno Alternaria alternata. Em relação aos valores de IC50 os menores valores apresentados pelo óleo essencial (75,83 µg mL-1) e pelo citral (58,24 µg mL-1) foram sobre o Bipolaris sp. O citral causou as maiores inibições miceliais, para todos os fitopatógenos.Given the importance of essential oils, this study evaluated the antioxidant activity and fungitoxic effects of lemongrass essential oil and its main constituent citral on mycelial inhibition of phytopathogens Fusarium oxysporum cubense, Colletotrichum gloeosporioides, Bipolaris sp. and Alternaria alternata. The antioxidant activity was evaluated by employing the DPPH free radical reduction method and oxidation tests of the system β-carotene/linoleic acid. For each method, a completely randomized design in a 4 x 5 factorial arrangement was used with four compounds (essential oil, citral, thymol and α-tocopherol) and five concentrations (5; 10; 25; 50 and 100 Mg L-1), with three replicates. The tests to determine fungitoxic activities were performed by applying the in vitro fumigation test on mycelial inhibition of studied phytopathogens. The treatments were arranged in a completely randomized design with three replicates and a factorial arrangement. The essential oil and citral showed little antioxidant activity by the methodology that measures the reduction of the stable radical DPPH; however, by the methodology that employs the emulsified β-carotene/linoleic acid system, these compounds showed significant antioxidant activities. At fungitoxic activities, the essential oil and citral showed greater activity against the phytopathogen Alternaria alternata. When compared to the values of IC50, the lowest values presented by the essential (75.83 µg mL-1) and citral (58.24 µg mL-1) oils were found for Bipolaris sp. Citral caused the greatest mycelial inhibition on all phytopathogens.

Copyright of Revista Ciência Agronômica is the property of Revista Ciencia Agronomica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Ciência Agronômica is the property of Revista Ciencia Agronomica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT The genus Capsicum belongs to the Solanaceae botanical family and is notable for the production of secondary metabolites of medicinal and economical importance. In vitro methods have been successfully utilized for the large scale production of plant secondary metabolites. The objective of this study was to establish a protocol for callus induction from leaves, nodal and internodal segments of the cultivar C. annuum var. annuum cv. Iberaba Jalapeño, and to determine the growth pattern of the calluses, aiming at the identification of the deceleration phase, when the callus cells must be subcultured for the establishment of cell suspensions and the production of secondary metabolites. The explants were inoculated into a medium supplemented with BA and 2,4-D in factorial combination. Percentage of callus induction and the explant area covered by callus cells (ACCC) were evaluated. The procedures that resulted in higher proliferation of callus cells were repeated in order to determine the growth curve of the calluses. The highest callus induction percentage and ACCC were observed with the combination of 2.22 µM BA + 18.10 µM 2,4-D for leaf and internodal explants and 2.22 µM BA + 9.05 µM 2,4-D for nodal explants. The calluses produced were friable and whitish, and their growth pattern followed a sigmoid shape. The deceleration phase started on the 31st day of cultivation for leaf explants, on the 26th for internodal explants, and on the 29th day for nodal explants.