Resistance to the two-spotted spider mite (Tetranychus urticae) by acylsucroses of wild tomato (Solanum pimpinellifolium) trichomes studied in a recombinant inbred line population

Abstract

Trichome-based host plant resistance is a complex mechanism that could be used in tomato breeding to control arthropod pests. The aims of this work were to evaluate the plant traits (density of trichomes and acylsucrose production) and the functional relationships of these traits with mortality, repellence, and oviposition of Tetranychus urticae Koch (Acari: Tetranychidae). We used a population of recombinant inbred lines (RILs) derived from the cross between the wild tomato, Solanum pimpinellifolium L. 'TO-937', and the cultivated tomato, Solanum lycopersicum L. Multiple regression analyses showed that high acylsucrose content and high type-IV trichome density increased mortality and repellence, and reduced oviposition of T. urticae. Single regression analyses showed that a logistic model best explained the relationship between mortality or repellence and acylsucrose content, whereas a negative-exponential model best described the relationship between oviposition and acylsucrose content. Linear models were the best-fits for the three resistance variables with trichome IV density. Probit analysis was used to estimate acylsucrose effective doses, and revealed that 31 and 10% of the RILs produced acylsucrose above the effective doses for 90% mortality or repellence, respectively. Altogether, these results indicate that S. pimpinellifolium may be a suitable genetic source of resistance to spider mites to be used in cultivated tomato.

Functionally Divergent Alleles and Duplicated Loci Encoding an Acyltransferase Contribute to Acylsugar Metabolite Diversity in Solanum Trichomes

“…Once secreted to the plant surface, the primary role of acylsugars is contributing to defense against a variety of insects including whiteflies, aphids, spider mites, and leaf miners (Hawthorne et al, 1992;Rodriguez et al, 1993;Liedl et al, 1995;Alba et al, 2009). Depending on the insect, the presence of acylsugars can be correlated with one or more modes of defense, including increased repellence, increased mortality, and reduced fecundity.…”

Identification of resistance to Bemisia tabaci Genn. in closely related wild relatives of cultivated tomato based on trichome type analysis and choice and no-choice assays

“…Mill.) accession TO937 (Alba et al 2009;Rodríguez-López et al 2011). Solanum galapagense, along with S. cheesmaniae (L. Riley) Fosberg (syn L. cheesmaniae L. Riley) and S. pimpinellifolium are closely related to cultivated tomato and introgression of resistance from these species may be easier and faster compared to the green-fruited species…”

Comportamiento poblacional de Tetranychus urticae Koch. (Acari: Tetranychidae) en variedades de tomate

“…Un estudio realizado por Alba et al (2009) encontraron diferencias altamente significativas al desarrollo de T. urticae entre las más susceptibles y las más resistente de S. pimpinellifolium (TO-937), debido a un elevado contenido de acilsacarosa y una alta densidad de tricomas tipo IV que aumentaron la mortalidad y repelencia y también se registró una reducción de la oviposición de T. urticae. Kawazu et al (2012) compararon los perfiles de expresión de los genes inducibles para ácido jasmónico (Pin2 y LapA1) y ácido salicílico (PRb-1b y GluB) en plantas de tomate en respuesta a la infestación de T. urticae, se activaron los genes para ácido jasmónico LapA1 y adicionalmente los genes para ácido salicílico (PRb-1b y GluB), lo cual representa una señal de que estas moléculas también intervienen de alguna forma en el proceso de resistencia en este cultivo.…”