Researchers at the University of Southampton have proposed that certain wild plant species possess attributes making them more suitable for human cultivation than others.
The scientists, investigating the origins of domesticated plants, state that understanding key genetic and morphological traits may provide important clues about developing future crops adapted to climate change.
They suggest examining today's existing undomesticated or underutilized plants to meet future challenges in developing varieties that resist rising global temperatures and unpredictable weather.
Domesticated plants are those adapted from the wild for human use, often over thousands of years. Approximately 12,000 years ago, hunter-gatherer societies began cultivating various species as reliable food sources. By repeatedly growing seeds from the best plants each season, humans slowly produced more robust crops with improved yields—however, only some wild species were domesticated while others were abandoned.
The researchers behind this study, published in the journal Trends in Ecology and Evolution, assert that useful, hidden properties in some wild species 'primed' them for domestication. Their research reviews past literature and evidence to examine why only a minority of wild plants were domesticated and how modern cultivated varieties differ genetically from their ancestors and present-day wild 'cousins'.
Lead author 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 percent of our calories." He adds, "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, including scientists from Oxford, Sheffield, and the Royal Botanical Gardens at Kew, identified three main factors influencing plant suitability for cultivation:
Plasticity: how a plant adapts to its environment. Quick-adapting plants with traits favored by humans are more likely to be useful for cultivation.
Genetic make-up: simpler is better. If a small number of genes influence beneficial traits, crop morphology evolves more easily.
Mutation rate: a faster mutation rate increases chances of beneficial changes. Quick mutations can expedite the process of generating larger seeds or tastier fruits.
The researchers conclude that understanding the complex factors leading to the dominance of certain plant species in cultivated crops can help identify wild crops that may be successfully adapted to future climate conditions.
Professor Chapman states, "When plants were first domesticated thousands of years ago, humans only knew the climate and weather conditions they would face at that present time. 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 consider how our crops will need to be resistant in the future."
The scientists believe that present-day wild plants, underutilized crops in local communities, or partially domesticated species may hold key traits that can be controlled through selection and precision breeding. They hope their study will inform future work aimed at improving food security in a rapidly changing climate.