Resistance of tomato genotypes with high level of acylsugars to Tetranychus evansi Baker & Pritchard

Abstract

The Lycopersicon pennellii accession LA716 has been used as a source of arthropod pest resistance in tomato breeding programs due the high contents of acylsugars presents in its leaflets. We investigated the relationship between high foliar acylsugar contents and repellence to spider mite Tetranychus evansi in plants with contrasting acylsugar levels, selected from F 2 and BC 1 F 2 (= F 2 of the first backcross towards L. esculentum) generations derived from the interespecific cross L. esculentum 'TOM-584' × L. pennellii LA716. Mite resistance was assessed by a repellence test. Plants selected for high levels of acylsugars in leaflets had mite repellence levels similar to that of LA716. The high correlation confirmed the association between high acylsugar levels and mite repellence. Key words: Lycopersicon esculentum, Lycopersicon pennellii, allelochemical, plant breeding, host plant resistance RESISTÊNCIA DE GENÓTIPOS DE TOMATEIRO COM ALTO TEOR DE ACILAÇÚCARES A Tetranychus evansi Baker & PritchardRESUMO: O acesso de Lycopersicon pennellii LA716 tem sido utilizado em programas de melhoramento do tomateiro devido à sua resistência a artrópodos-pragas, mediada pela presença de acilaçúcares nos folíolos. Foi verificada a correlação entre o teor de acilaçúcares em folíolos de tomateiros e a repelência ao ácaro Tetranychus evansi Baker & Pritchard. Foram selecionadas plantas contrastantes quanto aos níveis de acilaçúcares nos folíolos de populações F 2 e F 2 RC 1 (= F 2 do primeiro retrocruzamento para Lycopersicon esculentum) do cruzamento interespecífico de L. esculentum TOM 584 (baixo teor de acilaçúcares) e L. pennellii LA 716 (alto teor). Foi realizado um teste de repelência ao ácaro T. evansi, tomando por base a distância percorrida pelos ácaros nos folíolos. Os genótipos selecionados para alto teor de acilaçúcares, em média, foram responsáveis por reduções significativas nas distâncias percorridas pelos ácaros sobre a superfície do folíolo. A repelência ao ácaro T. evansi exercida pelas plantas selecionadas para alto teor de acilaçúcares deu-se de forma semelhante àquela conferida pelo genitor LA-716. As magnitudes das correlações encontradas confirmam a associação entre altos teores do aleloquímico e a repelência ao ácaro. Palavras-chave: Lycopersicon esculentum, Lycopersicon pennellii, aleloquímicos, melhoramento genético, resistência da planta hospedeira

Indirect selection of industrial tomato genotypes that are resistant to spider mites (Tetranychus urticae)

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Selection of processing tomato genotypes with high acyl sugar content that are resistant to the tomato pinworm

“…Accessions of S. pennellii have high levels of resistance to a large number of arthropod pests, including the tomato pinworm (Gonçalves et al, 2006;Saeidi et al, 2007;Pereira et al, 2008;Resende et al, 2006Resende et al, , 2008Resende et al, , 2009Gonçalves Neto et al, 2010). The resistance of S. pennellii has been associated with the presence of allelochemicals called acyl sugars, which are esters of fatty acids.…”

Resistance of tomato strains to the moth Tuta absoluta imparted by allelochemicals and trichome density

“…This species is considered to be one of the leading pests in South America with regard to the economic losses it causes (CASTELO BRANCO et al, 2003, RESENDE et al, 2008. The damage from infestations of the species can be observed in the shoots of the plants.…”