Tomatitto Intruduction

Tomatitto Introduction

From wild, blueberry-like fruit to the large domesticated tomatoes that people enjoy today, the evolution of one of the world’s most popular crops has been somewhat of an enigma until now.

Piecing together gaps in its history, a new genetic study suggests the modern tomato is more likely related to weed-like fruit in Mexico than to semi-domesticated versions in South America as commonly thought.

This discovery challenges the simplified notion that tomato domestication comprised two key transitions: from the wild Solanum pimpinellifolium L. to the cherry-sized S. lycopersicum L. var. cerasiforme (SLC) and then to the fully domesticated S. lycopersicum L. var. lycopersicum.

“We found that the SLC, this ‘intermediate’ group, has had a much more varied evolutionary history than simply being a stepping stone between wild and modern cultivated tomatoes,” explains senior author Ana Caicedo from the University of Massachusetts Amherst, US.

Shedding light on the “historically contentious” debate about SLC, the researchers’ analyses indicate this plant originated first as a wild species more than 70,000 years ago, which predates any domestication by humans. 

This finding was unexpected, says Caicedo, “and shows how complex the evolutionary trajectory of crop domestication can be”.

Typically, plant domestication involves cultivating wild specimens with desirable traits then later improving those qualities through selective breeding – but the process is protracted and can encounter several environmental disruptions including weather changes, water availability or pathogens.

The authors argue, therefore, that limited focus on the original wild species and final domesticated product could miss some favourable genes and traits along the plant’s evolutionary trajectory and therefore opportunities to improve current crops.

This could include strains that are disease or drought resistant, says first author Hamid Razifard, or have higher antioxidant and sugar content to enhance the fruit’s health benefits and taste, such as the researchers discovered in intermediate populations.