Genetic basis of fruit quality traits in processing tomatoes

Abstract

Tomato varieties used for processed products, such as paste, sauces, and crushed tomatoes, differ from their fresh-market counterparts based on plant structure, fruit morphology, and fruit biochemistry. Processing tomato varieties have been bred to withstand mechanical harvesting and to yield good-quality cooked products. Although there has been substantial research on fresh-market tomatoes, there needs to be more emphasis on the traits required for processing varieties. Characteristics such as juice thickness (consistency), ease of removing fruit skin (peelability), and fruit maturity concentration may not be important to fresh-market tomato growers; however, they play crucial roles in determining the best varieties for processing. Major genes involved in many processed quality traits, often subject to significant environmental influences, have yet to be revealed. Application of advanced genomic tools and gene-editing technologies, such as CRISPR Cas9, could clarify the leading players driving these traits and support breeding efforts. This review article presents what is known about the genetics underlying important key traits in processing tomatoes that impact the product quality and production efficiency of processed tomato products and addresses areas where more work is needed.