Geneticists Use CRISPR to Correct Tomato Breeding Conflict

In the 1950s, scientists found a wild tomato relative in the Galapagos Island that does not have a swollen part of the stem referred to as joint. Joints are the weak parts of the stem that make the fruit fall easily from the plant. Breeders then developed jointless tomatoes to prolong the stay of the fruits in the plants. However, when the jointless tomato was bred with the existing tomato varieties, the resulting plants had flower-bearing branches that produced many extra branches and looked like a broom, terminating in a host of flowers. This led to reduced number of fruits.

Years after, geneticist Zachary Lippman of Cold Spring Harbor Laboratory in New York and other researchers tracked down the gene responsible for the jointless trait and another gene that promotes the formation of a large green cap of leaf-like structures on top of the fruit. Then they used CRISPR-Cas9 to correct the conflict of the traits, leading to tomato plants with different plant architectures,including those with long, spindly flower-bearing branches to bushy, cauliflower-like bunches of flowers, and some with better yields.

Read more from Nature.