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Abstract Domestication of the apple was mainly driven by interspecific hybridization. In the present study, we report the haplotype-resolved genomes of the cultivated apple (Malus domesticacv. Gala) and its two major wild progenitors,M. sieversiiandM. sylvestris. Substantial variations are identified between the two haplotypes of each genome. Inference of genome ancestry identifies ~23% of the Gala genome as of hybrid origin. Deep sequencing of 91 accessions identifies selective sweeps in cultivated apples that originated from either of the two progenitors and are associated with important domestication traits. Construction and analyses of apple pan-genomes uncover thousands of new genes, with hundreds of them being selected from one of the progenitors and largely fixed in cultivated apples, revealing that introgression of new genes/alleles is a hallmark of apple domestication through hybridization. Finally, transcriptome profiles of Gala fruits at 13 developmental stages unravel ~19% of genes displaying allele-specific expression, including many associated with fruit quality.
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Changing climate risks for high-value tree fruit production across the United States
Abstract Climate change poses growing risks to global agriculture including perennial tree fruit such as apples that hold important nutritional, cultural, and economic value. This study quantifies historical trends in climate metrics affecting apple growth, production, and quality, which remain understudied. Utilizing the high-resolution gridMET dataset, we analyzed trends (1979–2022) in several key metrics across the U.S.—cold degree days, chill portions, last day of spring frost, growing degree days (GDD), extreme heat days (daily maximum temperature >34 °C), and warm nights (daily minimum temperatures >15 °C). We found significant trends across large parts of the U.S. in all metrics, with the spatial patterns consistent with pronounced warming across the western states in summer and winter. Yakima County, WA, Kent County, MI, Wayne County, NY—leading apple-producers—showed significant decreasing trends in cold degree days and increasing trends in GDD and warm fall nights. Yakima county, with over 48 870 acres of apple orchards, showed significant changes in five of the six metrics—earlier last day of spring frost, fewer cold degree days, increasing GDD over the overall growth period, and more extreme heat days and warm nights. These trends could negatively affect apple production by reducing the dormancy period, altering bloom timing, increasing sunburn risk, and diminishing apple appearance and quality. Large parts of the U.S. experience detrimental trends in multiple metrics simultaneously that indicate the potential for compounding negative impacts on the production and quality of apples and other tree fruit, emphasizing the need for developing and adopting adaptation strategies.
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- Award ID(s):
- 1934383
- PAR ID:
- 10557396
- Publisher / Repository:
- IOP Publishing
- Date Published:
- Journal Name:
- Environmental Research Letters
- Volume:
- 19
- Issue:
- 12
- ISSN:
- 1748-9326
- Format(s):
- Medium: X Size: Article No. 124092
- Size(s):
- Article No. 124092
- Sponsoring Org:
- National Science Foundation
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