The typical red, modern tomato is about one hundred times bigger than its pea-sized wild ancestor, which originally came from the Andes region in South America. To track the long history of tomato breeding and understand how such human-imposed selection has changed the genome of the plant, an international team of researchers, have sequenced 360 tomato plant varieties, including wild and domesticated species. The results are published in Nature Genetics.
“Two years ago we only had one genome and now we have more than 300!” said Harry Klee, a horticultural scientist at the University of Florida who studies tomatoes and was not involved in the current study. “What makes this work really important is that it’s a foundation for future improvements on the tomato. We can now find causative genes for the traits we want. This is going to have a huge impact for tomato breeding very quickly.”
The large-scale effort, led by Sanwen Huang of the Institute of Vegetables and Flowers at the Chinese Academy of Agricultural Sciences in Beijing, China, has uncovered a signature of the modern, processing tomato used to make ketchup, a variant that gives some tomato varieties a pink color, and the extra loci introduced to cultivated tomatoes as a result of recent breeding with wild species, among other features of the plant’s genome.
The study builds on the first tomato genome, of the Heinz 1706 inbred, cultivated variety, published in Nature in 2012. For the new work, the researchers sequenced 333 red varieties, 10 wild tomato species, and 17 modern commercial hybrids from around the world.
“One genome sequence is not enough because variation is the raw material needed for breeding,” said Huang, who was part of the 2012 sequencing project. “So we decided to create a variation map for the tomato, which will give breeders a holistic view of the species’ differences.”
Read full, original article: 360-Degree View of the Tomato