Abstract
Phytochemicals not only determine the taste and smell of plants and their products, they also play a crucial role in resistance against pests and pathogens. In previous work, we identified a form of resistance to thrips (Frankliniella occidentalis) expressed in leaves of pepper (Capsicum annuum). In the current study, we characterized leaves of an interspecific C. annuum × C. chinense F2 population for variation in their global phytochemical composition by an untargeted metabolomics approach. Quantitative trait locus (QTL) mapping resulted in metabolite QTLs (mQTLs) for 304 of the 674 metabolites detected. We compared the QTL mapping results to those obtained earlier on fruits in the same population. Very different QTL hotspots were found, suggesting that the metabolite composition of leaves and fruits is regulated independently. Six leaf mQTLs co-located with the major QTL for resistance to thrips, which we previously identified in the same F2 population. Four of them were significantly correlated to thrips resistance, including two diterpene glycosides and a flavonoid compound which may indicate a possible role of these metabolites in thrips resistance. If a causal role of some of these metabolites in resistance can be proven this will help in the identification of the causal gene(s) and it may provide leads for the identification of other sources of thrips resistance in Capsicum and in other species.
Highlights
Peppers (Capsicum spp.) are among the most cultivated vegetables in the world today (FAOSTAT 2016)
The aims of our current study were (1) to determine metabolite profiles in leaves of pepper, detectable by liquid chromatography–mass spectrometry (LC–MS), and to map these in the F2 population; (2) to compare the distribution of metabolite QTLs (mQTLs) found in leaves with those in fruits as detected by (Wahyuni et al 2014); and (3) to study the colocation of leaf mQTLs with the main thrips (Frankliniella occidentalis) resistance Quantitative trait locus (QTL) on chromosome 6 (Maharijaya et al 2015) in order to identify metabolites that are potentially involved in thrips resistance in pepper
Mapping of thrips resistance in the F2 population is described by Maharijaya et al (2015), which contains all details on the thrips rearing and assays used; damage caused by thrips larvae and the survival of first and second instar larval stages were used as parameters of resistance in a no-choice assay
Summary
Peppers (Capsicum spp.) are among the most cultivated vegetables in the world today (FAOSTAT 2016). They can be used as food product, fresh or as cooked vegetable, as Handling Editor: Rupesh Kariyat. The quality of pepper fruits is determined by characteristics such as color, shape, size, uniformity, shelf life, taste, and biochemical composition. Fruits of pepper contain high levels of nutritional compounds, including carotenoids (provitamin A), ascorbic acid (vitamin C), tocopherols (vitamin E), phenolic compounds, flavonoids, and capsaicinoids. In contrast to pepper fruits, no comprehensive metabolite profiling has yet been published for pepper leaves
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
