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Scientists investigate what makes some plant species 'ripe' for domestication

Researchers at the University of Southampton have proposed that some wild plant species possess certain attributes which make them more suitable for human cultivation than others.

The scientists, investigating the origins of domesticated plants, say understanding these key genetic and morphological traits may provide important clues about how to develop future, climate change adapted crops.

They suggest that looking at today's existing undomesticated or underutilized plants could help meet future challenges of developing varieties to resist rising global temperatures and unpredictable weather.

Domesticated plants are those which have been adapted from the wild for human use, often over thousands of years. Around 12,000 years ago, hunter-gatherer societies began cultivating a wide array of species as more reliable sources of food. By repeatedly growing seeds from their best plants each season, humans slowly produced more robust crops with improved yields—but only some of the wild species were domesticated and others were abandoned.

The researchers behind this new study, published in the journal , say useful, hidden properties in some wild species 'primed' them for domestication. Their research reviews a host of past literature and evidence to examine why just a minority of these wild plants were domesticated and how modern cultivated varieties differ at a genetic level from their ancestors and present day wild 'cousins."

Senior author of the study, Professor Mark Chapman of the University of Southampton, explains, "Tens of thousands of plant species are edible, yet just a few hundred have been domesticated and a mere 15 species provide 90% of our calories.

"Hundreds of wild plants were collected during the Neolithic period by humans, but were later abandoned as food sources. We have explored which genetic or physical traits facilitated or constrained the domestication of wild species."

The team, which also includes scientists from the universities of Oxford, Sheffield and the Royal Botanical Gardens at Kew, identified three main influencing factors which make plants suitable for human cultivation:

• Plasticity—how a plant adapts to its environment. Quick and easily adapting plants with traits that humans favored are more likely to have been useful for human cultivation.
• Genetic make-up—the simpler, the better. If a small number of genes influence the traits that humans could benefit from, then evolution of the crop morphology is more easily achieved.
• Mutation rate—the faster, the more chance of change. If a plant mutates quickly the process of trial and error to generate bigger seeds or tastier fruits will take less time.
  

The researchers say that understanding the complex, interrelated factors which lead to certain plant species dominating in domesticated crops can help us understand which wild crops may be successfully adapted to future conditions caused by climate change.

"When plants were first domesticated thousands of year ago, humans only knew the climate and weather conditions they would face at that present time," explains Professor Chapman. "Now, using sophisticated climate modeling, we can predict how our world will warm and how our weather will change in the decades to come. This gives us the opportunity to think about the ways in which our crops will need to be resistant in the future."

The scientists conclude that present day wild plants, underutilized crops in local communities, or partially domesticated species may hold key, useful traits which can be controlled through selection and precision breeding. They hope their study will help inform future work to adapt species with the aim of improving our food security in a fast changing world climate.