Thanks to an experiment initiated before the onset of the Great Depression, researchers have successfully identified the genes responsible for barley’s incredible adaptability, a crucial component in the production of beer and whiskey. This understanding could help ensure the crop’s survival as climate change accelerates.
Thanks to an experiment initiated before the onset of the Great Depression, researchers have successfully identified the genes responsible for barley’s incredible adaptability, a crucial component in the production of beer and whiskey. This understanding could help ensure the crop’s survival as climate change accelerates.
Barley is cultivated in places ranging from Asia and Egypt to Norway and the Andes of South America, making it one of the most significant cereal crops in the world for at least 12,000 years. Its ability to thrive in various regions has been supported by random genetic mutations throughout its history.
Recognizing the specific genes involved is essential for predicting which types of barley will succeed in areas now facing rising temperatures, extended droughts, and more intense storms.
“Breeders have long recognized the necessity of developing crops that are well-suited to their local environments. A century ago, this experiment began in Davis, California, using barley varieties from all over the globe to find those best adapted to local conditions,” explained Dan Koenig, a geneticist at UC Riverside.
“The early scientists lacked the means to identify the genes that make barley thrive in different settings. However, we can now analyze millions of genetic variations in my lab in a single experiment,” Koenig said.
The new study published in the journal Science outlines dozens of genes that enhance barley’s adaptability. Koenig, who is the corresponding author, pointed out that some identified genes assist barley in timing its reproductive cycles to optimize the growing season.
“If a plant flowers too early or too late, it may fail to produce seeds,” Koenig noted. “To maximize seed production, flowering needs to happen within a very specific timeframe.”
In California, barley must complete its flowering phase before the dry season starts; otherwise, there won’t be enough water for seed formation. However, if flowering occurs too early, the plants risk frost exposure. The researchers found that genetics play a key role in flowering at the right time, with various genes encouraging early flowering and others limiting late flowering.
Finding these genes was challenging. “One major issue with studying genetic adaptations is that it can take decades, as we can only grow one generation of barley in a year,” Koenig mentioned.
Fortunately, Koenig and his team have access to the Barley Composite Cross II experiment, which began in Davis, California, in 1929—one of the longest-running biological experiments globally. It aimed to develop new barley varieties suited for the California market. Over decades, breeders tested thousands of genetically distinct barley types, with the variants best suited for the hot, dry climate of California surviving and becoming more prevalent.
Koenig’s team realized that the seeds from this long-running experiment could serve as a kind of time machine, allowing them to directly observe adaptation processes and identify the genes linked to survival.
Throughout 58 growing seasons, the field transitioned from 15,000 genetically unique plants to a single lineage representing 60% of the population—all without any human selection.
“We were astonished by the degree of change that unfolded over such a short period in evolutionary terms,” Koenig remarked. “Natural selection dramatically altered genetic diversity across the entire genome within just a human lifetime.”
The research team intends to conduct further studies using long-term experimental data from various climates to explore how flowering timing might be adjusted differently.
Additionally, the team seeks to understand a peculiar observation: during the Davis experiment, the diverse plant population markedly increased yields by almost double as they adapted to Northern California, yet this improvement still lags behind what breeders achieve through selective breeding.
“Yield might compete with other characteristics, like growth speed or height,” Koenig explained. “Farmers prefer plants that are good neighbors, yet this preference might hinder environmental adaptation.”
Since barley shares genetic similarities with wheat, rice, and corn, the insights gained on its adaptability could potentially benefit these other grains in adjusting to climate extremes.
By employing advanced techniques such as genome engineering and CRISPR, researchers may be able to create crops that bloom at more advantageous times.
“Barley’s capacity to adapt has been fundamental to the development of human civilization. Comprehending this is crucial not only for the ongoing production of alcoholic beverages but also for developing future crops and enhancing their resilience as global conditions change,” Koenig concluded.
