Resistência de genótipos de tomateiro à mosca-branca Bemisia tabaci (Gennadius) biótipo B (Hemiptera: Aleyrodidae)

-Brazil is one of the world's largest tomato producer, but considerable part of the production is lost due to the attack of Bemisia tabaci (Genn.) B biotype. Resistant germoplasm plants can be an important method for B. tabaci control in integrated pest management approaches. The attractiveness and ovipositional preference of B. tabaci for 17 tomato genotypes were evaluated in a free-choice test. Trials were set up in a randomized block design with ten replicates. Each replicate (one tomato plant per pot) was placed in a cage (80 x 50 x 50 cm) and infested with 1,000 adults during four days. Linear correlation tests were applied between the number of insects and eggs and number of trichomes in each tomato genotype. LA716, LA444-1 and PI134418 genotypes were the least attractive, while the 'Santa Clara' was the most attractive; PI134417 trapped the largest number of adults. LA716 genotype (4.1 eggs/leafl et and 2.1 cm 2 /eggs per leafl et) was the least preferred for whitefl y oviposition; NAV1062, 'Fanny', LA1335, 'Santa Clara' and IAC294 were the most preferred genotypes. The glandular trichomes density was negatively correlated with whitefl y's attractiveness and oviposition per leafl et and per leaf, and positively with the number of trapped insects. The non-glandular trichomes density was negatively correlated with the number of trapped insects and positively with whitefl y's oviposition per cm 2 /leafl et and per cm 2 /leaf. LA716 had high antixenosis level (ovipositional nonpreference) toward B. tabaci B biotype related with type IV glandular trichome.

Section: Resultssupporting

confidence: 57%

Section: Resultsmentioning

confidence: 66%

Influence of trichomes on attractiveness and ovipositional preference of Bemisia tabaci (Genn.) B biotype (Hemiptera: Aleyrodidae) on tomato genotypes

Oriani¹,

Vendramim²

2010

“…These results for T. vaporariorum together with the results from Baldin et al (2005) regarding B. tabaci, suggest that FCN 3-5 S. habrochaites is an important source of resistance to whiteflies in tomato breeding programs.…”

Section: Discussionsupporting

confidence: 53%

“…In the no-choice assay, FCN 3-5 (which showed no amplification of the REX-1 marker) had the lowest number of eggs per female per day as well as the lowest female survival average, suggesting that this genotype possesses mechanisms that limit the development and survival of T. vaporariorum. Baldin et al (2005), working on two accessions of S. habrochaites (PI 134417 and PI 134418), found a lower oviposition rate and a no-preference of Bemisia tabaci, which they ascribed to plant volatiles that could prevent whiteflies from landing and ovipositing on leaflets.…”

Section: Discussionmentioning

confidence: 99%

Resistance of tomato genotypes to the greenhouse whitefly Trialeurodes vaporariorum (West.) (Hemiptera: Aleyrodidae)

Lucatti¹,

Alvarez²,

Machado³

et al. 2010

-The greenhouse whitefly, Trialeurodes vaporariorum Westwood, is the most common and abundant whitefly in Argentine horticultural greenhouse crops, especially in tomato (Solanum lycopersicum). Resistance in some wild tomato relatives, such as S. peruvianum, S. habrochaites and S. pennellii to the greenhouse whitefly has been described. The Mi gene confers effective resistance against several species of insects, among them the sweet potato whitefly, Bemisia tabaci Gennadius. Resistance to T. vaporariorum was found in the prebreeding line FCN 93-6-2, derived from a cross between S. lycopersicum cultivar Uco Plata INTA (MiMi) and the wild line FCN 3-5 S. habrochaites. The purpose of this study was to evaluate resistance to T. vaporariorum in tomato genotypes and to study the relationship between this resistance and the presence of the REX-1 marker, which is linked to the Mi gene. In a free-choice assay, the average number of adults per leaf and the number of immatures on the middle and basal plant parts were analyzed. In a no-choice assay, the oviposition rate and adult survival rate were calculated. For all variables analyzed, FCN 3-5 was the most resistant strain. Variations were found in the F 2 progeny between the prebreeding line FCN 13-1-6-1 and cv. Uco Plata INTA. Results from the F 2 progeny indicate that resistance to T. vaporariorum may be polygenic with transgressive segregation. Whitefly resistance was found to be independent of the REX-1 marker.

“…Baldin et al (2005), ao avaliar os possíveis mecanismos de resistência de diferentes genótipos de tomateiro (Lycopersicon spp.) em relação à moscabranca, constataram que os tricomas glandulares desempenham papel fundamental para a não-fi xação ou mortalidade do inseto na planta, devendo ser devidamente explorados nos programas de melhoramento, a fi m de oferecer novas ferramentas para o controle deste inseto.…”

Section: Influência Dos Tipos De Tricomas Foliaresunclassified

Comportamento de oviposição da mosca-branca Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae) biótipo B em tomateiro

Vendramim¹,

Souza²,

Ongarelli³

2009

-The objective of this work was to evaluate the infl uence of the leaf surface, the insect geotropic behavior and the type of foliar trichome on Bemisia tabaci (Genn.) biotype B oviposition on tomato leaves. Bemisia tabaci females were confi ned in acrylic boxes in which tomato leafl ets were fi xed at the bottom and top part of the boxes to allow insects to access the leaf surface to be tested (adaxial and/or abaxial) in both no-choice and free choice tests. Oviposition was always higher when the leaf was offered at the top of the box and preferably at the abaxial leaf surface. The effects of leaf trichomes (glandular and non glandular) on B. tabaci oviposition was evaluated by offering the abaxial surface of tomato leafl ets to females after a 70% ethanol wash to remove glandular exsudates against a control treatment (without a ethanol wash). Oviposition was concentrated mostly near to non glandular trichomes, showing whitefl y females can discriminate among the trichomes.KEY WORDS: Host selection, oviposition preference, glandular trichome, trichome exsudate RESUMO -Avaliou-se a infl uência da face foliar, do comportamento geotrópico do inseto e do tipo de tricoma foliar sobre a oviposição de Bemisia tabaci (Genn.) biótipo B em folhas de tomateiro. Para avaliação desses efeitos foram realizados vários ensaios nos quais as fêmeas foram confi nadas em caixas de acrílico. Folíolos de tomateiro foram fi xados no topo e na base das caixas, de tal forma a permitir o acesso dos insetos às faces adaxial e abaxial de maneira isolada e concomitante (com e sem chance de escolha). Os insetos sempre depositaram maior número de ovos quando a superfície foliar se encontrava no topo da caixa e, de maneira geral, preferiram depositar seus ovos na face abaxial dos folíolos. Para avaliar o efeito do tipo de tricoma (glandular e não-glandular) sobre a oviposição de B. tabaci, a face abaxial dos folíolos de tomateiro foi oferecida a cerca de 30 fêmeas para oviposição em cada caixa de acrílico. Foram oferecidos folíolos previamente lavados com etanol a 70% (de forma a eliminar os exsudatos glandulares) e sem lavagem prévia. A maior parte da oviposição ocorreu ao lado dos tricomas não-glandulares, demonstrando que o inseto discrimina o tipo de tricoma. PALAVRAS-CHAVE: Seleção hospedeira, preferência para oviposição, tricoma glandular, exsudato do tricoma A mosca-branca Bemisia tabaci (Genn.) biótipo B é atualmente uma das principais pragas do tomateiro, difícil de ser controlada devido ao seu hábito de permanecer na face abaxial das folhas (Villas Boas et al 1997). Os danos desse biótipo são mais intensos em função da sua maior agressividade, que resulta da maior fecundidade, ampla gama de hospedeiros, alta resistência aos inseticidas e capacidade de causar desordens fi siológicas nas plantas (Costa & Brown 1990, Prabhaker et al 1998.As fêmeas de B. tabaci depositam seus ovos preferencialmente na face abaxial das folhas mais novas (Simmons 1994(Simmons , 1999, talvez pelo fato de a face abaxial apresentar cutícula geralmen...