Dinâmica populacional de Aceria litchii (Keifer) (Acari: eriophyidae) revela respostas diferenciais de variedades de lichieiras
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Data
2019-11-07
Autores
Amaral, Ingrid [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Com o aparecimento do ácaro-da-erinose Aceria litchii (Keifer) (Acari: Eriophyidae) no Brasil em 2010, a produtividade das lichieiras (Litchi chinensis Sonn.) diminuiu drasticamente nas principais regiões produtoras. A alimentação do ácaro desencadeia a formação da erinose em folíolos, ramos e frutos que afeta a produtividade e a qualidade dos frutos. O objetivo do trabalho foi estudar a dinâmica populacional de A. licthii em variedades de lichia visando a detecção de fontes de resistência ao ácaro. A pesquisa foi desenvolvida em um banco de germoplasma da Faculdade de Ciências Agrárias e Veterinárias, UNESP – Jaboticabal, estado de São Paulo, com lichieiras em produção. Foram avaliadas as variedades Bengal, Americana, Brewster, Groff e WB4. As avaliações foram realizadas mensalmente durante o período de dois anos. Em cada coleta foram amostrados folíolos com presença de erinose com aspecto mais jovem possível. Para contagem dos ácaros, era esperado um período de 24 horas para secagem parcial dos folíolos. A contagem foi realizada sob microscópio estereoscópio em 1,0 cm² por folíolo na região abaxial. Para análise de severidade da erinose, foi necessário elaborar uma escala de notas capaz de representar diferenças entre as variedades quanto à severidade da erinose. A escala varia de 0 a 7, e consistiu-se em estimar a porcentagem de ramos afetados em um quadrante pré-determinado de cada planta. Aceria litchii foi encontrado em todas as lichieiras durante todo o período do estudo, atingindo níveis populacionais mais elevados nos meses de outubro e novembro. Sintomas de erinose foram encontrados em todas as variedades. Entretanto, houve resposta diferencial entre as variedades, nos quais a menor densidade populacional do ácaro foi encontrada na variedade Americana, assim como esta também foi a menos danificada pela erinose. Os resultados obtidos fornecem subsídios fundamentais para programas de melhoramento genético, bem como são úteis para o estabelecimento de estratégias de manejo mais adequadas.
With the appearance of the erinosis mite Aceria litchii (Keifer) (Acari: Eriophyidae) in Brazil in 2010, the productivity of litchi (Litchi chinensis Sonn.) Has decreased dramatically in the main producing regions. The mite feeding triggers erinose formation in leaflets, twigs and fruits that affects fruit productivity and quality. The objective of this work was to study the population dynamics of A. licthii in litchi varieties aiming at detecting sources of mite resistance. The research was carried out in a germplasm bank of the Faculty of Agricultural and Veterinary Sciences, UNESP - Jaboticabal, state of São Paulo, with litchi in production. The varieties Bengal, Americana, Brewster, Groff and WB4 were evaluated. Evaluations were performed monthly over a two-year period. Leaflets were sampled in each collection, with the presence of the youngest possible erinosis. For mite counting, a period of 24 hours was expected for partial drying of the leaflets. Counting was performed under stereoscope microscope at 1.0 cm² per leaflet in the abaxial region. For analysis of erinosis severity, it was necessary to elaborate a grade scale capable of representing differences between the varieties regarding erinosis severity. The scale ranges from 0 to 7, and consisted of estimating the percentage of affected branches in a predetermined quadrant of each plant. Aceria litchii was found in all litchi throughout the study period, reaching higher population levels in October and November. Symptoms of erinosis have been found in all varieties. However, there was a differential response among the varieties, in which the lowest population density of the mite was found in the Americana variety, as well as the lesser damage by erinosis. The obtained results provide fundamental subsidies for breeding programs, as well as useful for establishing more appropriate management strategies. Keywords: lychee, erinosis, ‘Bengal’, ‘Americana’.
With the appearance of the erinosis mite Aceria litchii (Keifer) (Acari: Eriophyidae) in Brazil in 2010, the productivity of litchi (Litchi chinensis Sonn.) Has decreased dramatically in the main producing regions. The mite feeding triggers erinose formation in leaflets, twigs and fruits that affects fruit productivity and quality. The objective of this work was to study the population dynamics of A. licthii in litchi varieties aiming at detecting sources of mite resistance. The research was carried out in a germplasm bank of the Faculty of Agricultural and Veterinary Sciences, UNESP - Jaboticabal, state of São Paulo, with litchi in production. The varieties Bengal, Americana, Brewster, Groff and WB4 were evaluated. Evaluations were performed monthly over a two-year period. Leaflets were sampled in each collection, with the presence of the youngest possible erinosis. For mite counting, a period of 24 hours was expected for partial drying of the leaflets. Counting was performed under stereoscope microscope at 1.0 cm² per leaflet in the abaxial region. For analysis of erinosis severity, it was necessary to elaborate a grade scale capable of representing differences between the varieties regarding erinosis severity. The scale ranges from 0 to 7, and consisted of estimating the percentage of affected branches in a predetermined quadrant of each plant. Aceria litchii was found in all litchi throughout the study period, reaching higher population levels in October and November. Symptoms of erinosis have been found in all varieties. However, there was a differential response among the varieties, in which the lowest population density of the mite was found in the Americana variety, as well as the lesser damage by erinosis. The obtained results provide fundamental subsidies for breeding programs, as well as useful for establishing more appropriate management strategies. Keywords: lychee, erinosis, ‘Bengal’, ‘Americana’.
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Lichia, Erinose, 'Bengal', 'Americana'