Variabilidade populacional de Plutella xylostella (L., 1758) (Lepidoptera: Plutellidae) e suscetibilidade a Bacillus thuringiensis Berliner
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Data
2013-02-18
Autores
Laurentis, Valéria Lucas de [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
O objetivo deste estudo foi verificar, por meio de métodos moleculares, possíveis diferenças entre populações de Plutella xylostella (PX, PA, PC e PJ) de três estados brasileiros produtores de brassicáceas e avaliar a suscetibilidade e os efeitos subletais nestas populações à bioinseticidas e isolados de Bacillus thuringiensis. Foram utilizados os métodos de sequenciamento do gene COI e ISSR-PCR para analisar a estrutura genética das populações. Para avaliar a suscetibilidade e os efeitos subletais foram pulverizados em discos foliares de couve de 8 cm de diâmetro os isolados 153.30A, 49.19A, T08.024, E7, E28, E47, 41.7L, 20.7L, HD-1 e Bt tenebrionis e os produtos Btt090®, Dipel®, Agree® e Xentari®. Após a secagem, os discos foliares foram oferecidos para alimentação de lagartas de segundo ínstar de P. xylostella de cada população, em placas de Petri. As pupas foram individualizadas em placas com poços tipo Elisa® até a emergência dos adultos. Os adultos foram separados em casais e transferidos para gaiolas para oviposição. Os insetos foram observados até a morte dos adultos, sendo avaliado: viabilidade e duração larval e pupal, consumo foliar, peso das pupas, razão sexual, longevidade, número de ovos/fêmea/dia, período de incubação e viabilidade dos ovos. Os produtos/isolados que causaram mortalidade superior a 80% foram utilizados para estimar os valores de CL50. As populações apresentaram diferenças nas estruturas genéticas, sendo PJ a mais diferente. Os produtos Agree®, Dipel® e Xentari® e os isolados 49.19A, E47 e HD1 causaram 100% de mortalidade para todas as populações. De modo geral, Dipel® e HD1 foram mais tóxicos dentre os produtos e isolados, respectivamente, devido às menores CL50. Os isolados T08.024 e E28 foram os que mais afetaram negativamente as características biológicas da...
The aim of this study was to detect possible differences among populations of Plutella xylostella (PX, PA, PC and PJ), from three Brazilian states that produce brassicaceas, and to evaluate the susceptibility and sublethal effects of these populations to Bacillus thuringiensis bioinsecticides and strains. We used the methods of COI gene sequencing and ISSR-PCR to analyze the genetic structure of the populations. To evaluate the susceptibility and sublethal effects, isolates 153.30A, 49.19A, T08.024, E7, E28, E47, 41.7L, 20.7L, HD-1 and Bt tenebrionis and products Btt090®, Dipel®, Agree® and Xentari® were sprayed on 8-cm-diameter kale leaf discs. After drying, the leaf disks were offered to fed second instar caterpillars of P. xylostella from each population, in Petri dishes. The pupae were placed in separated wells plates with Elisa ® until adult emergence. The adults were separated into couples and transferred to cages for oviposition. We observed the insects until the adults death, evaluating: larval and pupal viability and period, leaf consumption, pupal weight, sex ratio, longevity, number of eggs/female/day, incubation period and egg viability. Products/strains that caused mortality exceeding 80% were used to estimate the values of LC50. The populations showed differences in genetic structures, being PJ the most different one. Agree®, Dipel®, Xentari®, and the isolates 49.19A, E47 and HD1 caused 100% mortality for all populations. Generally, HD1 and Dipel® were the most toxic among products and strains, due to lower LC50. The isolates T08.024 and E28 were the ones that most affected negatively the biological characteristics of the pest, despite they didn’t cause 100% of mortality... (Complete abstract click electronic access below)
The aim of this study was to detect possible differences among populations of Plutella xylostella (PX, PA, PC and PJ), from three Brazilian states that produce brassicaceas, and to evaluate the susceptibility and sublethal effects of these populations to Bacillus thuringiensis bioinsecticides and strains. We used the methods of COI gene sequencing and ISSR-PCR to analyze the genetic structure of the populations. To evaluate the susceptibility and sublethal effects, isolates 153.30A, 49.19A, T08.024, E7, E28, E47, 41.7L, 20.7L, HD-1 and Bt tenebrionis and products Btt090®, Dipel®, Agree® and Xentari® were sprayed on 8-cm-diameter kale leaf discs. After drying, the leaf disks were offered to fed second instar caterpillars of P. xylostella from each population, in Petri dishes. The pupae were placed in separated wells plates with Elisa ® until adult emergence. The adults were separated into couples and transferred to cages for oviposition. We observed the insects until the adults death, evaluating: larval and pupal viability and period, leaf consumption, pupal weight, sex ratio, longevity, number of eggs/female/day, incubation period and egg viability. Products/strains that caused mortality exceeding 80% were used to estimate the values of LC50. The populations showed differences in genetic structures, being PJ the most different one. Agree®, Dipel®, Xentari®, and the isolates 49.19A, E47 and HD1 caused 100% mortality for all populations. Generally, HD1 and Dipel® were the most toxic among products and strains, due to lower LC50. The isolates T08.024 and E28 were the ones that most affected negatively the biological characteristics of the pest, despite they didn’t cause 100% of mortality... (Complete abstract click electronic access below)
Descrição
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Inseto - Criação, Traça, Bacillus thuringiensis, Pragas agricolas - Controle biologico, Bacillus thurigiensis
Como citar
LAURENTIS, Valéria Lucas de. Variabilidade populacional de Plutella xylostella (L., 1758) (Lepidoptera: Plutellidae) e suscetibilidade a Bacillus thuringiensis Berliner. 2013. iv, 76 f. Dissertação (mestrado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, 2013.