Tomatoes often lack the characteristic good taste that consumers expect. In recent years, the fruit and vegetable industry has focused on traits such as yield, colour, and fruit size; however, flavour has been largely forgotten, at least for varieties that are grown in bulk and are cheap to purchase. Tomato volatiles are one of the most important flavour contributors along with sugars and organic acids. Over 400 volatiles are present in tomato, but only about 30 are considered critical to tomato flavour. The purpose of this study was to identify volatile Quantitative Trait Loci (vQTL) using publicly available Solanum pennellii and Solanum habrochaites introgression lines (ILs). Detection of vQTL is an essential milestone for identification of candidate genes involved in tomato flavour. Identification of vQTL was undertaken by screening the ILs using Atmospheric Pressure Chemical Ionisation Mass Spectrometry (APCI-MS) and Gas Chromatography Mass Spectrometry (GC-MS). Additionally key volatiles and their interactions were evaluated in a series of sensory experiments using tomato juice and tomato purée. The study revealed that, the S. pennellii population had several major effects including those on IL1-4, which had a vQTL for C6 volatile E-2-hexenal. It was possible to identify a sub-IL, 1-4-1 that also harboured this vQTL. In this IL1-4-1 region of chromosome 1, 122 genes were present including a possible, candidate gene likely to be involved in lipoxygenase pathway. The sensory experiments showed strong impact of methyl salicylate on other volatiles; E-2-hexenal and citral showed positive effects in purée studies. Determined taste detection thresholds for volatiles in tomato juice and purée were established. Keywords: volatile, genes, tomato juice, tomato purée, flavour.

As a major food source potato delivers significant levels of minerals to the human diet. The aim of this study was to understand the control over the mineral concentrations found in tubers. The three-dimensional patterns of mineral distribution in tubers give clues to the processes leading to storage in the tuber. Within the tuber flesh, calcium and phosphorus content decreased towards the centre of the tuber (on FW basis). The elements iron, magnesium, zinc, manganese, sulphur and chlorine were higher at the stem end, while potassium was higher at the bud end. Remobilisation of minerals within the tuber was evident after six months of cold storage. Mineral variation was explored in potato germplasm. Three diverse germplasm collections, the Commonwealth Potato Collection, the Phureja and Tuberosum Core Collection and the Neotuberosum Population demonstrated wide variation for tuber mineral concentrations, an interaction with tuber yield and, on multivariate analysis, consistent parallels between some minerals suggesting unsuspected shared processes affecting their concentrations. The 12601ab1 x Stirling tetraploid mapping population was used to identify QTls for tuber mineral concentration using REML analysis to account for local field variation. Transgressive segregation for tuber mineral concentrations was detected. The genetic map for this population was extended using DArT markers and QTLs were identified on all 12 linkage groups for all minerals studied. Two bulk segregant analyses were performed to add precision to the QTL analysis. One approach identified candidate genes on the potato genome sequence and used nearby SSRs to seek association in the tetraploid mapping population. A second approach used the variation present in the highly diverse Neotuberosum Population to identify DArT markers which were associated with the tails of the distribution of minerals. Using the latter approach, single superscaffolds containing candidate loci and trait-associated DArT markers could be aligned with a small part of mapping population QTLs, providing additional resolution.