researchers Genomica Application Laboratory and elsewhere are releasing improved genome assemblies. Arabica coffee (arabica coffee tree)a hybrid of coffee tree and robusta coffee (Coffea genus) contributes to approximately 60% of the world's coffee production.
arabica coffee tree derived from interbreeding between modern ancestors Coffea genus and another closely related coffee species, coffee tree.
As a result of this hybridization, arabica coffee treeflavor and its large and complex genome pose challenges to breeding and genetic research.
Some partial genome assemblies arabica coffee tree is currently available, but the mechanisms that generate its genetic diversity are unknown.
Researchers Michele Morgante and Gabriele Di Gaspero and their colleagues at the Istituto di Genomica Appplicata used the latest sequencing technology to generate a more complete genome assembly. arabica coffee treeallowing detailed analysis of its chromosomal structure.
Analysis of the genome, including previously inaccessible regions such as around centromeres, revealed differences in genome structure, function, and evolution contributed by the two ancestral species, particularly in genes involved in caffeine biosynthesis. found.
For this study, they also analyzed the genomes of 174 samples collected from different species within Earth. coffee genus and found a very low level of genetic diversity within it. arabica coffee tree.
Diversity found to be increasing in some regions arabica coffee tree Varieties of specific genomic regions due to two different sources of variation: chromosomal abnormalities and gene segments provided by so-called Timor hybrids. Arabica coffee x Canephora coffee tree A hybrid from East Timor.
This hybrid is the parent line for many modern varieties that combine disease resistance traits. Coffea genus And its unique flavor is arabica coffee tree.
The authors argue that genetic diversity arabica coffee tree Essential for commercial success, this discovery could help develop new coffee varieties with desirable traits, such as disease resistance or different flavor profiles.
“Resequence data from large accession sets reveal low intraspecific diversity at the center of species origin. arabica coffee tree” the authors write in their paper.
“Across a limited number of genomic regions, the diversity of some cultivated genotypes has increased to levels similar to that observed in one of the ancestral species. Coffea genusThis is probably the result of introgression derived from Timor hybrids. ”
“We also found that in addition to very few early exchanges between homologous chromosomes, there are many recent chromosomal abnormalities such as aneuploidies, deletions, duplications, and exchanges.”
“These phenomena are still polymorphic in the germplasm and may be the root cause of genetic variation in such low-variability species.”
of paper Published in this week's magazine nature communications.
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S. Scalabrine other. 2024.Chromosome-scale assembly reveals chromosomal abnormalities and exchanges that generate genetic diversity arabica coffee tree germ plasm. Nat Commune 15,463; doi: 10.1038/s41467-023-44449-8
Source: www.sci.news
