QTL mapping of insect resistance components of Solanum galapagense

Ben Vosman,Richard G F Visser,Fien Meijer-Dekens,Henriëtte Van Eekelen,Ric C H De Vos,Wendy Van’T Westende,Roeland E Voorrips,Atiyeh Kashaninia

doi:10.1007/s00122-018-3239-7

Abstract

Key messageQTLs for insect resistance parameters, trichome type IV development, and more than 200 non-volatile metabolites, including 76 acyl sugars, all co-locate at the end of Chromosome 2 of Solanum galapagense.Host plant resistance is gaining importance as more and more insecticides are being banned due to environmental concerns. In tomato, resistance towards insects is found in wild relatives and has been attributed to the presence of glandular trichomes and their specific phytochemical composition. In this paper, we describe the results from a large-scale QTL mapping of data from whitefly resistance tests, trichome phenotyping and a comprehensive metabolomics analysis in a recombinant inbred line population derived from a cross between the cultivated Solanum lycopersicum and the wild relative S. galapagense, which is resistant to a range of pest insects. One major QTL (Wf-1) was found to govern the resistance against two different whitefly species. This QTL co-localizes with QTLs for the presence of trichomes type IV and V, as well as all 76 acyl sugars detected and about 150 other non-volatile phytochemicals, including methyl esters of the flavonols myricetin and quercetin. Based on these results, we hypothesize that Wf-1 is regulating the formation of glandular trichome type IV on the leaf epidermis, enabling the production and accumulation of bioactive metabolites in this type of trichomes.

Highlights

Insects are a major constraint in crop production
We address the following questions: (1) Does the Wf-1 QTL identified for B. tabaci resistance affect another whitefly species, T. vaporariorum? (2) Does the QTL play a role in the accumulation of metabolites? (3) Do acyl sugars map to this Wf-1 QTL region and are possibly other regions of the genome involved as well? To address these questions, we made use of a recombinant inbred line population that was developed based on the F2 population previously created (Firdaus et al 2013)
The recombinant inbred line (RIL) population, which was obtained by single seed decent, was based on the F2 derived from a single F1 plant of the cross between a T MV® Moneymaker (PRI91117) and S. galapagense (PRI95004) (Firdaus et al 2013)

Summary

Introduction

Insects are a major constraint in crop production. Do they cause direct losses by feeding, and indirectly through the viruses they transmit (Navas-Castillo et al 2011). Resistance to insects has been identified in wild relatives of the cultivated tomato (Firdaus et al 2012; Muigai et al 2003; Rodriguez-Lopez et al 2011; Silva et al 2014; Vosman et al 2018). Several lines of evidence show that the glandular trichome type IV is important in resistance against insects (Firdaus et al 2012; Muigai et al 2003; Rakha et al 2017a, c; Simmons et al 2005)

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Results

Discussion

Conclusion