Wild relatives of domesticated crops represent a source of genetic diversity for improving genetically impoverished crop cultivars. Global warming endangers populations of wild crop relatives, but the populations’ genetic responses to the stresses imposed by global warming remain uncertain.
The researchers characterized genetic changes in 10 Israeli populations of wild emmer wheat (WEW), a wild relative of cultivated wheat, between 1980 and 2008. Estimated overall genetic diversity in the populations was lower in 2008 than in 1980. The 2008 WEW genomes exhibited signs of elevated selection and increased mutational burdens compared with the 1980 genomes.
However, most of the populations also carried more beneficial mutations in 2008 than in 1980. Genetic responses specific to variations in temperature and rainfall were varied and complex.
High temperatures and low rainfall over the 28-year period were both associated with more deleterious mutations, higher nucleotide diversity, and lower genetic differentiation among populations in 2008 than in 1980.
High temperatures were also associated with lower mutational burden and reduced selection, while low rainfall was associated with high mutational burden.
The results enable better understanding of evolutionary responses in plant populations threatened by global warming and provide a foundation for modeling plant adaptability and vulnerability to global warming, according to the authors.
Genetic responses of wheat to global warming
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