A chemical genetic roadmap to improved tomato flavor

Abstract

Modern commercial tomato varieties are substantially less flavorful than heirloom varieties. To understand and ultimately correct this deficiency, we quantified flavor-associated chemicals in 398 modern, heirloom, and wild accessions. A subset of these accessions was evaluated in consumer panels, identifying the chemicals that made the most important contributions to flavor and consumer liking. We found that modern commercial varieties contain significantly lower amounts of many of these important flavor chemicals than older varieties. Whole-genome sequencing and a genome-wide association study permitted identification of genetic loci that affect most of the target flavor chemicals, including sugars, acids, and volatiles. Together, these results provide an understanding of the flavor deficiencies in modern commercial varieties and the information necessary for the recovery of good flavor through molecular breeding.

Canalization of Tomato Fruit Metabolism

“…Indeed, the phenylalanine QTL was even maintained following the application of the highly stringent Bonferroni correction. Since the pathway of starch degradation (which yields sugars) and those related to phenylalanine-derived volatiles contribute to fruit nutritional quality and flavor (Zhang et al, 2015;Tieman et al, 2017), it is possible that these pathways are related to the production of enticing fruits that aid in seed dispersal.…”

An InDel in the Promoter of Al-ACTIVATED MALATE TRANSPORTER9 Selected during Tomato Domestication Determines Fruit Malate Contents and Aluminum Tolerance

“…Also, both linkage disequilibrium and linkage mapping indicated that the underlying natural variation in leaf Cd accumulation in the global Arabidopsis population was caused by different Heavy Metal ATPase 3 (At-HMA3) alleles (Chao et al, 2012). Recently, an mGWAS analyzed 28 chemicals specifically associated with consumer preference and flavor intensity, using 2,014,488 common SNPs distributed among 398 modern, heirloom, and wild tomato accessions, which yielded a total of 251 associated loci for 20 traits, including malate content (Tieman et al, 2017).…”

“…In this study, we analyzed an enlarged mapping population of 272 accessions (Lin et al, 2014;Tieman et al, 2017) with GWAS methods to identify reliable and high precision QTLs that contribute to fruit malate content in a diverse tomato population. Furthermore, we integrated the mGWAS approach with analyses of gene expression patterns, genetic variations, and T-DNA (CRISPR/ Cas9)-derived mutants to functionally characterize a malate contentrelated QTL.…”

Effects of Barley (Hordeum Vulgare L.) Variety and Growing Environment on Beer Flavor

“…To this end, a mapping experiment is in progress using a larger sample of Oregon Promise doubled haploids. That larger and more robust data set can be used, together with the available barley genome sequence (21) and metabolomic data, to identify candidate genes and biochemical pathways for specific flavors, as described for tomato and cannabis (8,37).…”