A research group led by Prof. LI Chuanyou from the Institute of Genetics and Developmental Biology (IGDB) of the Chinese Academy of Sciences (CAS) has developed a rapid breeding strategy to generate tomato lines with different colored fruits from red-fruited materials by CRISPR/Cas9-mediated multiplex gene editing.
Using this strategy, the researchers have engineered red-fruited cultivar Alisa Craig to a series of tomato genotypes with different fruit colors, including yellow, brown, pink, light-yellow, pink-brown, yellow-green, and light-green.
Tomato is the world's most popular fruit/vegetable and its color is considering a vital trait in horticultural crops which markedly affects customer preferences. The fruit color is determined by the accumulation of different pigments such as carotenoids and flavonoids etc. It is a multigenic trait which takes years to introgress all color-related genes in a single genetic background using traditional cross-breeding, and to avoid linkage drag during this process is also difficult.
Using their developed approach, transgene-free plants with different fruit colors can be obtained in less than one year, and the most positive point is that it can retain the qualities of the original cultivar and does not affect other important agronomic traits.
This strategy provides a reference for improving multigene-controlled traits by multiplex gene editing and can be easily extended to other horticultural crops.
Multiplex gene editing rapidly customizes tomato cultivars with different fruit colors. (Image by IGDB)