(CS-30-6) Improving tomato flavor using biochemistry, genomics and breeding

Body of Abstract: Modern fresh market tomatoes have been bred for agronomic traits such as shelf life, disease resistance and yield; however, consumers prefer the taste of locally produced heirloom varieties. Tomato flavor deficiency is due to a cumulative loss of superior alleles affecting flavor volatiles while breeding for other traits. It is extremely difficult to breed for flavor because of the genetic complexity of the flavor phenotype as well as a lack of a simple assay that can define consumer preferences. Tomato flavor is a result of interactions between sugars, acids and aroma volatiles, with volatile compounds giving the tomato fruit its characteristic aroma and flavor. We have measured 68 potential flavor-associated chemicals in over 700 tomato varieties, including modern, heirloom and ancestral tomato accessions. Over 150 of these varieties were evaluated in large consumer panels for overall liking and sweet and sour intensity. The biochemical and consumer data permitted us to determine which flavor compound correlate with consumer preferences. In addition, Genome Wide Association Studies (GWAS) identified loci associated with altered levels of acids, sugars and aroma volatiles. We have used marker-assisted breeding to introgress flavor associated loci from heirloom parents into modern tomato varieties. Introduction of several flavor loci into a modern tomato variety has resulted in improved flavor as assessed by consumers.