Scientists from the Agricultural University of Iceland have identified genes for height and early maturity to improve northern lines
As climate change creates hotter, drier weather in southern latitudes and pushes agriculture north, a team of barley researchers has harnessed genetic tools to help producers adapt.
Magnus Göransson from the Norwegian University of Life Sciences and the Agricultural University of Iceland looked at 84 spring barley lines from northern Europe. Specifically, they were looking for genetics that help barley thrive in northern fields, which offer a lot of daylight but low temperatures.
Göransson and his colleagues used growth chambers to control light and heat to mimic conditions in Nordic fields now and under expected effects of climate change. The aim was to tease out how day length and temperature affect time to maturity and the height of the crop.
Perhaps not surprisingly, the Icelandic varieties “showed a unique pattern of early maturity not found elsewhere.” Another finding was that lower temperatures resulted in taller plants. This is a particular problem in Iceland, where excess height in cold, wet autumn weather can make the crop more prone to lodging.
The researchers coupled their results with a genome-wide association study, or GWAS. This allows many varieties to be compared side-by-side to identify differences. In this case, the researchers found several genes associated with how much heat the barley needed to head out and how much it needed to mature. One gene was associated with plant height.
Just shy of the Arctic Circle at 64 degrees north latitude, Reykjavik, Iceland, is about 660 kilometres further north than Fort Vermillion, Alta., one of the northernmost farming communities in Canada’s Peace River region.
Despite this, the growing season is slightly longer in Iceland with seeding possible in late April and harvest in September. This is thanks to the Irminger Current, a branch of the Gulf Stream that brings warm air up from more southern latitudes.
Iceland does, however, remain at the northern limit of possible barley cultivation. While it does get plentiful sunshine, it never gets very warm — an average of 11 C in its warmest month versus 17.5 C for the Peace River region in July. This is particularly challenging in late summer and early fall when the barley heads are filling.
In their paper in the journal Crop Science, Göransson and his colleagues cited reports that show barley yields have stagnated in south and central Europe, while yields in more northern fields are rising. This is attributed to climate change, something that is expected to intensify with time.
The trend does open opportunity for improved barley lines adapted to more northern latitudes. The researchers reported that current varieties have lagged behind southern varieties in yield, for instance, suggesting a goal for barley breeders.
Identifying genes associated with traits like height and early maturity allows breeders to screen new varieties before taking them to field trials. This significantly cuts costs and time to get new varieties into the field. The researchers expect breeders will use this new knowledge to combine “early maturity and height stability with traits such as quality, further enabling the northward expansion of grain production.”