Caracterização de resistência de genótipos de couve-de-folhas Brassica oleracea (L.) var. acephala a Bemisia tabaci biótipo B (Hemiptera: Aleyrodidae)
Carregando...
Data
2017-02-23
Autores
Domingos, Georgea Maria [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
A couve-de-folhas, Brassica oleracea (L.) var. acephala, de grande importância nutricional para a alimentação humana, sofre limitação de seu cultivo pelo ataque de insetos-praga como a mosca-branca, Bemisia tabaci biótipo B (Genn.) (Hemiptera: Aleyrodidae), que ocasiona danos diretos e indiretos às plantas, podendo comprometer a produtividade no campo. O controle químico é o método mais utilizado para o manejo deste inseto, porém, características como elevado potencial reprodutivo, capacidade de adaptação a condições adversas e grande número de hospedeiros fazem com que o método químico não atinja a eficiência desejada. Em razão disto, métodos alternativos como o uso de plantas resistentes é considerado uma estratégia com reconhecida eficiência no manejo integrado de pragas (MIP). Neste trabalho, 32 genótipos de couve-de-folhas foram avaliados sob o ataque de B. tabaci biótipo B, visando caracterizar possíveis tipos de resistência (antixenose e antibiose) contra este inseto. Numa primeira etapa, foram realizados ensaios de antixenose (com e sem chance de escolha) a fim de avaliar a colonização e a oviposição nos diferentes materiais. Nesse mesmo estudo a coloração das folhas foi também determinada, visando estabelecer correlações. Posteriormente, foi realizado ensaio de desempenho biológico, com 13 genótipos mais promissores (primeira etapa) a fim de caracterizar a ocorrência de antibiose. Com base nos resultados obtidos, os genótipos HS-20, OE e VA foram os menos atrativos aos adultos da mosca-branca, indicando expressão de antixenose a esse inseto. Os genótipos VE e J revelaram-se os menos ovipositados tanto em ensaio de livre escolha como em ausência de escolha. Os genótipos P1C, MG, LG prolongaram o ciclo da mosca-branca, indicando a expressão de antibiose e/ou antixenose contra B. tabaci biótipo B. MOP, IMAN W e VE destacaram-se com os menores índices de viabilidade ninfal, também indicando a ocorrência dessa categoria de resistência. Os dados obtidos neste estudo podem ser úteis aos programas de melhoramento genético focando o desenvolvimento de brássicas resistentes a B. tabaci biótipo B.
Collard green, Brassica oleracea (L.) var. acephala, which is of great nutritional importance for human consumption, is endangered by the attack of insect pests such as the whitefly, Bemisia tabaci biotype B (Genn.) (Hemiptera: Aleyrodidae), which causes direct and indirect damages to plants, and may compromise productivity in the field. The chemical control is the most used method for the management of this insect, however, characteristics such as high reproductive potential, adaptability to adverse conditions and large number of hosts cause the chemical method does not achieve the desired efficiency. Because of this, alternative methods such as the use of resistant plants is considered a strategy with recognized efficiency in integrated pest management (IPM). In this work, 32 genotypes of leaf collard green were evaluated under the attack of B. tabaci biotype B, aiming to characterize possible types of resistance (antioxenose and antibiosis) against this insect. In a first step, antixenosis tests were performed (with and without a choice) in order to evaluate the colonization and oviposition in the different materials. In this same study, the leaf color was also determined, aiming to establish correlations. Subsequently, a biological performance test was performed, with 13 more promising genotypes (first stage) in order to characterize the occurrence of antibiosis. Based on the results obtained, genotypes HS-20, OE and VA were the least attractive to adults of the whitefly, indicating expression of antixenosis to this insect. The VE and J genotypes were the least oviposited both in the free choice and the absence of choice assays. The genotypes P1C, MG, LG prolonged the whitefly cycle, indicating the expression of antibiosis and/or antixenosis against B. tabaci biotype B. MOP, IMAN W and VE stood out with the lowest rates of nymphal viability, also indicating the occurrence of this category of resistance. The data obtained in this study may be useful for breeding programs focusing on the development of brassicas resistant to B. tabaci biotype B.
Collard green, Brassica oleracea (L.) var. acephala, which is of great nutritional importance for human consumption, is endangered by the attack of insect pests such as the whitefly, Bemisia tabaci biotype B (Genn.) (Hemiptera: Aleyrodidae), which causes direct and indirect damages to plants, and may compromise productivity in the field. The chemical control is the most used method for the management of this insect, however, characteristics such as high reproductive potential, adaptability to adverse conditions and large number of hosts cause the chemical method does not achieve the desired efficiency. Because of this, alternative methods such as the use of resistant plants is considered a strategy with recognized efficiency in integrated pest management (IPM). In this work, 32 genotypes of leaf collard green were evaluated under the attack of B. tabaci biotype B, aiming to characterize possible types of resistance (antioxenose and antibiosis) against this insect. In a first step, antixenosis tests were performed (with and without a choice) in order to evaluate the colonization and oviposition in the different materials. In this same study, the leaf color was also determined, aiming to establish correlations. Subsequently, a biological performance test was performed, with 13 more promising genotypes (first stage) in order to characterize the occurrence of antibiosis. Based on the results obtained, genotypes HS-20, OE and VA were the least attractive to adults of the whitefly, indicating expression of antixenosis to this insect. The VE and J genotypes were the least oviposited both in the free choice and the absence of choice assays. The genotypes P1C, MG, LG prolonged the whitefly cycle, indicating the expression of antibiosis and/or antixenosis against B. tabaci biotype B. MOP, IMAN W and VE stood out with the lowest rates of nymphal viability, also indicating the occurrence of this category of resistance. The data obtained in this study may be useful for breeding programs focusing on the development of brassicas resistant to B. tabaci biotype B.
Descrição
Palavras-chave
Brassicaceae, Mosca-branca, Resistência de plantas a insetos, Antixenose, Antibiose