Alterações bioquímicas de plantas de tomate (Solanum esculentum L.) e pimentão (Capsicum annuum L.) infestadas com as espécies crípticas de Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) MEAM1 e MED
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Data
2021-04-09
Autores
Toledo, Claudia Aparecida de Lima [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
A mosca-branca, Bemisia tabaci (Gennadius) (Hemiptera:Aleyrodidae) é uma das pragas mais invasivas do mundo causando danos diretos e indiretos, interferindo na fisiologia, anatomia e bioquímica das plantas. Buscando entender a influência da infestação e as estratégias de defesa das plantas este estudo, teve como objetivos: 1) Avaliar a influência da infestação de espécies crípticas de B. tabaci MED e MEAM1 em aspectos fisiológicos e bioquímicos de plantas de tomateiro; e 2) Analisar a influência da infestação de B. tabaci MED em plantas de pimentão sob aplicação de biorregulador. O trabalho foi dividido em quatro capítulos, o capítulo I revisão de literátura. Os capítulos II e III foram realizados em tomateiro, sendo um na fase vegetativa e o outro na floração, sendo estudadas plantas de tomateiro infestadas por B. tabaci MED, B. tabaci MEAM1 e plantas não infestadas, analisando-se a influência nas trocas gasosas, fluorescência da clorofila a no PSII (fotossistema II) e aspectos bioquímicos (Fenóis totais, flavonoides totais, superóxido dismutase - SOD, peroxidase - POD e polifenoloxidase – PPO) Quanto ao IV capítulo, o estudo foi realizado em pimentão avaliando-se diferentes dosagens do biorregulador Stimulate® (0; 0,25; 0,5; 0,75; 1,0; 1,25 Litros.ha-1) em plantas infestadas por B. tabaci MED, e a influência das diferentes dosagens no teste de livre escolha, parâmetros biológicos (ovo ao adulto) e as respostas bioquímicas das plantas infestadas (fenóis totais, SOD, POD e PPO). Os ensaios foram conduzidos na Faculdade de Ciências Agronômicas – FCA da Universidade Estadual Paulista “Julio Mesquita Filho” – UNESP, Campus de Botucatu. Os experimentos com plantas de tomate (I- vegetativo; II- floração) foram realizados de julho a setembro. Os experimentos foram conduzidos em ambiente protegido, e as plantas cultivadas em gaiolas individuais envoltas por tecido do tipo agrotêxtil de coloração branca. O ensaio com teste de livre escolha e parâmetros biológicos nas plantas de pimentão foram realizados em condições de laboratório (27±2ºC e 14:10h fotoperíodo). As plantas de tomateiro no estádio vegetativo, quando infestadas por B. tabaci MED apresentaram menor taxa de assimilação de CO2 e condutância estomática quando comparada as plantas controle. Quanto aos parâmetros bioquímicos, verificou-se que MED apresentou maior atividade das enzimas de defesa no segundo e terceiro ínstar, o que indica que as plantas são mais resistentes ao ataque. No segundo experimento com tomate - floração, verificou-se que MED provocou menor condutância estomática, concentração interna de CO2 na folha, transpiração, e aumentou a eficiência do uso da água nas plantas infestadas. Por outro lado, MEAM1 provocou nas plantas infestadas a redução da atividade da enzima POD em todos os estádios de desenvolvimento do inseto. Diante do exposto, podemos mencionar que a maior preferência de B. tabaci MEAM1 por tomateiro quando comparamos a B. tabaci MED pode está atrelado a redução da atividade da POD. Quanto ao ensaio com plantas de pimentão tratadas com Stimulate®, não se verificou influência do biorregulador sobre a atratividade e biologia dos insetos. Todavia, a influência na planta na dose de 1,0 L.ha-1 favoreceram a produção de compostos de defesa, reduzindo o estresse causado pelo inseto-praga.
The whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of the most invasive pests in the world causing direct and indirect damage, interfering with the physiology, anatomy and biochemistry of plants Seeking to make sense of the influence of infestation and plant defense strategies, this study aimed to1) Evaluate the influence of the infestation of cryptic species of B. tabaci MED and MEAM1 on physiological and biochemical aspects of tomato plants; and 2) To analyze the influence of B. tabaci MED infestation in sweet pepper plants under bioregulator application. The work was divided into four chapters, chapter I literature review. Chapters II and III were carried out in tomato plants, one in the vegetative phase and the other in flowering, being studied tomato plants infested by B. tabaci MED, B. tabaci MEAM1 and non-infested plants, analyzing the influence on gas exchange, chlorophyll a fluorescence in PSII (photosystem II) and biochemical aspects (Total phenols, total flavonoids, superoxide dismutase - SOD, peroxidase - POD and polyphenoloxidase - PPO), aiming to understand the stress caused by the infestation of cryptic species. As for chapter IV, the study was carried out on sweet pepper, evaluating different dosages of the Stimulate® bioregulator (0; 0.25; 0.5; 0.75; 1.0; 1.25 Liters.ha-1) in plants infested by B. tabaci MED, and the influence of different dosages on the free choice test, biological parameters (egg to adult) and biochemical responses of the infested plants (total phenols, SOD, POD and PPO). The trials were conducted at the Faculty of Agronomic Sciences - FCA of the Paulista State University "Julio Mesquita Filho" - UNESP, Botucatu Campus. Experiments with tomato plants (I- vegetative; II- flowering) were carried out from July to September. The experiments were conducted in a protected environment, and the plants grown in individual cages spun by a white agrotextile fabric. The assay with free choice test and biological parameters in pepper plants were performed under laboratory conditions (27 ± 2ºC and 14: 10h photoperiod). Tomato plants in the vegetative stage, when infested with B. tabaci MED, showed a lower CO2 assimilation rate and stomatal conductance when compared to control plants. As for the biochemical parameters, it was found that MED showed greater activity of defense enzymes in the second and third instar, which indicates that the plants are more resistant to attack. In the second experiment with tomato - flowering, it was found that MED caused lower stomatal conductance, internal CO2 concentration in the leaf, transpiration, and increased the efficiency of water use in the infested plants. On the other hand, MEAM1 caused a reduction in the activity of the POD enzyme in the infested plants at all stages of development of the insect. Given the above, we can mention that the greater preference of B. tabaci MEAM1 for tomato when compared to B. tabaci MED may be linked to the reduction in POD activity. As for the assay with sweet pepper plants treated with Stimulate®, there was no influence of the bioregulator on the attractiveness and biology of the insects. However, the influence on the plant at a dose of 1.0 L.ha-1 favored the production of defense compounds, reducing the stress caused by the insect pest.
The whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of the most invasive pests in the world causing direct and indirect damage, interfering with the physiology, anatomy and biochemistry of plants Seeking to make sense of the influence of infestation and plant defense strategies, this study aimed to1) Evaluate the influence of the infestation of cryptic species of B. tabaci MED and MEAM1 on physiological and biochemical aspects of tomato plants; and 2) To analyze the influence of B. tabaci MED infestation in sweet pepper plants under bioregulator application. The work was divided into four chapters, chapter I literature review. Chapters II and III were carried out in tomato plants, one in the vegetative phase and the other in flowering, being studied tomato plants infested by B. tabaci MED, B. tabaci MEAM1 and non-infested plants, analyzing the influence on gas exchange, chlorophyll a fluorescence in PSII (photosystem II) and biochemical aspects (Total phenols, total flavonoids, superoxide dismutase - SOD, peroxidase - POD and polyphenoloxidase - PPO), aiming to understand the stress caused by the infestation of cryptic species. As for chapter IV, the study was carried out on sweet pepper, evaluating different dosages of the Stimulate® bioregulator (0; 0.25; 0.5; 0.75; 1.0; 1.25 Liters.ha-1) in plants infested by B. tabaci MED, and the influence of different dosages on the free choice test, biological parameters (egg to adult) and biochemical responses of the infested plants (total phenols, SOD, POD and PPO). The trials were conducted at the Faculty of Agronomic Sciences - FCA of the Paulista State University "Julio Mesquita Filho" - UNESP, Botucatu Campus. Experiments with tomato plants (I- vegetative; II- flowering) were carried out from July to September. The experiments were conducted in a protected environment, and the plants grown in individual cages spun by a white agrotextile fabric. The assay with free choice test and biological parameters in pepper plants were performed under laboratory conditions (27 ± 2ºC and 14: 10h photoperiod). Tomato plants in the vegetative stage, when infested with B. tabaci MED, showed a lower CO2 assimilation rate and stomatal conductance when compared to control plants. As for the biochemical parameters, it was found that MED showed greater activity of defense enzymes in the second and third instar, which indicates that the plants are more resistant to attack. In the second experiment with tomato - flowering, it was found that MED caused lower stomatal conductance, internal CO2 concentration in the leaf, transpiration, and increased the efficiency of water use in the infested plants. On the other hand, MEAM1 caused a reduction in the activity of the POD enzyme in the infested plants at all stages of development of the insect. Given the above, we can mention that the greater preference of B. tabaci MEAM1 for tomato when compared to B. tabaci MED may be linked to the reduction in POD activity. As for the assay with sweet pepper plants treated with Stimulate®, there was no influence of the bioregulator on the attractiveness and biology of the insects. However, the influence on the plant at a dose of 1.0 L.ha-1 favored the production of defense compounds, reducing the stress caused by the insect pest.
Descrição
Palavras-chave
Solanum esculentum L., Capsicum annuum L., Fotossíntese, Fluorescência da clorofila A, Enzimas, Relação inseto-planta, Photosynthesis, Chlorophyll a fluorescence, Enzymes, Insect-plant relationship