The silver birch (Betula pendula) is one of the major trees for forest products in the Northern Hemisphere, according to biologist Victor Albert, who just co-led a Finnish-funded project that hoped to illuminate the evolutionary history of the birch. Birch is among the more widely used woods for veneer and plywood worldwide. Silver birch, which was the focus of the study, is used in everything from plywood and interior trim to boxes and turned objects. According to Albert, “[o]thers, like spruce, pine and poplar, all have genome sequences, but birch did not—until now.”
The research team, including Jaakko Kangasjärvi, Ykä Helariutta, Petri Auvinen and Jarkko Salojärvi of the University of Helsinki in Finland, discovered gene mutations that could prove quite valuable to multiple industries.
Together they sequenced about 80 individuals of Betula pendula, more commonly known as the silver birch. The silver birch is native to Europe and southwest Asia, so the team sampled populations of the species “up and down Finland, down to Germany, over to Norway and Ireland, and all the way up to Siberia.”
Thanks to the 80 genomes sequenced, the researchers were able to identify genetic mutations that could potentially benefit multiple industries. To do this, the researchers searched for distinctive stretches of DNA within the genomes called “selective sweeps” that identify genetic regions that are critical to the survival and development of the species.
The team found sweeps that influence tree growth—important for increasing production—in addition to selective sweeps associated with environmental conditions. “The selective sweeps we identified may be the basis for local adaptation for different populations of birch,” Salojärvi stresses. “Trees in Siberia are under different selective pressure from trees in Finland, so genes are being tweaked in different ways in these two places to allow these plants to better adjust to their environment.”
The researchers hope that, as Helariutta said, “[a]n understanding of these natural adaptations can facilitate genetic engineering and artificial selection,” making their research “very useful for forest biotechnology.”
Image credits: The Woodland Trust and Marcye Philbrook
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