- ‘King of the conifers,’ the sugar pine has largest genome ever sequenced
- It is one of the tallest trees in the world, and pincones are 10-20 inches long
- The trees are threatened by fungal pathogen, drought, and bark beetles
The sugar pine is the ‘king of the conifers,’ and it’s got a massive genome to support its title.
Scientists have found that the genome of the sugar pine is not only 10 times the size of the human genome, but is the largest ever sequenced for any organism.
These findings could prove to be extremely valuable in preserving the endangered tree.
The sugar pine, Pinus lambertiana, can be found in throughout the stretch of California and Oregon, and goes as far south as Baja Mexico.
It is one of the tallest trees in the world, and its massive pinecones average between 10 and 20 inches in length.
Since the early-mid 1900s, these trees have suffered from a fungal pathogen called ‘white pine blister rust,’ and are continually threatened by damage from bark beetles, drought, and a lack of snow in the Sierra.
‘Having the genome sequence allows us to discover the underlying genetic determinants of disease resistance, which will greatly facilitate reforestation efforts,’ says David Neale, a forest tree geneticist at the University of California, Davis.
‘We can now give forest managers modern, rapid genetic tools to identify resistant trees.
‘The sugar pine has important environmental value as a key component of California forests, ecological and recreational value throughout the Sierra Nevada, and economic value as a source of timber.’
More than 100 species of the Pinus genus, which are found all through temperate regions across the globe, fall into two major subgroups: yellow pines, and white pines.
Last year, Neale and other researchers sequenced the genome of the loblolly pine, a member of the yellow pines. At the time, it was considered to be very large.
The sugar pine, a white pine, was found to have a genome 1.5 times larger than the loblolly.
These sequences can now be used as reference for future studies.
‘The sequencing and assembly of these two pine genomes reaches the present-day limits of genomic technologies and methods,’ says geneticist Charles Langley.
‘Like the human genome reference sequence, they are not yet complete, but they do provide an almost complete ‘parts list,’ and a draft of the ‘instructions.’
Before sequencing existed, emeritus research geneticist with the US Forest Service, Bohun Kinloch, bred the pines to test progenies.
Through this method, he was able to detect a rare blister rust resistance gene found in ‘parent’ sugar pine trees.
‘The US Forest Service plants seedlings from resistant parent trees into forests, so the new diagnostic tools derived from the reference sequences will speed the finding of disease-resistant parent trees directly, bypassing costly progeny testing,’ Kinloch says.
‘Seeds planted from these parents will help protect new generations of sugar pine trees from the devastating blister rust pathogen.’
H/t reader kevin a.
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