@article{choquette_weldekidan_brewer_davis_wisser_holland_2023, title={Enhancing adaptation of tropical maize to temperate environments using genomic selection}, volume={6}, ISSN={["2160-1836"]}, url={https://doi.org/10.1093/g3journal/jkad141}, DOI={10.1093/g3journal/jkad141}, abstractNote={Abstract Tropical maize can be used to diversify the genetic base of temperate germplasm and help create climate-adapted cultivars. However, tropical maize is unadapted to temperate environments, in which sensitivities to long photoperiods and cooler temperatures result in severely delayed flowering times, developmental defects, and little to no yield. Overcoming this maladaptive syndrome can require a decade of phenotypic selection in a targeted, temperate environment. To accelerate the incorporation of tropical diversity in temperate breeding pools, we tested if an additional generation of genomic selection can be used in an off-season nursery where phenotypic selection is not very effective. Prediction models were trained using flowering time recorded on random individuals in separate lineages of a heterogenous population grown at two northern U.S. latitudes. Direct phenotypic selection and genomic prediction model training was performed within each target environment and lineage, followed by genomic prediction of random intermated progenies in the off-season nursery. Performance of genomic prediction models was evaluated on self-fertilized progenies of prediction candidates grown in both target locations in the following summer season. Prediction abilities ranged from 0.30 to 0.40 among populations and evaluation environments. Prediction models with varying marker effect distributions or spatial field effects had similar accuracies. Our results suggest that genomic selection in a single off-season generation could increase genetic gains for flowering time by more than 50% compared to direct selection in summer seasons only, reducing the time required to change the population mean to an acceptably adapted flowering time by about one-third to one-half.}, journal={G3-GENES GENOMES GENETICS}, author={Choquette, Nicole E. and Weldekidan, Teclemariam and Brewer, Jason and Davis, Scott B. and Wisser, Randall J. and Holland, James B.}, editor={Lipka, AEditor}, year={2023}, month={Jun} }
 @article{choquette_holland_weldekidan_drouault_leon_flint-garcia_lauter_murray_xu_wisser_2023, title={Environment-specific selection alters flowering-time plasticity and results in pervasive pleiotropic responses in maize}, volume={2}, ISSN={["1469-8137"]}, url={https://doi.org/10.1111/nph.18769}, DOI={10.1111/nph.18769}, abstractNote={Summary Crop genetic diversity for climate adaptations is globally partitioned. We performed experimental evolution in maize to understand the response to selection and how plant germplasm can be moved across geographical zones. Initialized with a common population of tropical origin, artificial selection on flowering time was performed for two generations at eight field sites spanning 25° latitude, a 2800 km transect. We then jointly tested all selection lineages across the original sites of selection, for the target trait and 23 other traits. Modeling intergenerational shifts in a physiological reaction norm revealed separate components for flowering‐time plasticity. Generalized and local modes of selection altered the plasticity of each lineage, leading to a latitudinal pattern in the responses to selection that were strongly driven by photoperiod. This transformation led to widespread changes in developmental, architectural, and yield traits, expressed collectively in an environment‐dependent manner. Furthermore, selection for flowering time alone alleviated a maladaptive syndrome and improved yields for tropical maize in the temperate zone. Our findings show how phenotypic selection can rapidly shift the flowering phenology and plasticity of maize. They also demonstrate that selecting crops to local conditions can accelerate adaptation to climate change.}, journal={NEW PHYTOLOGIST}, author={Choquette, Nicole E. and Holland, James B. and Weldekidan, Teclemariam and Drouault, Justine and Leon, Natalia and Flint-Garcia, Sherry and Lauter, Nick and Murray, Seth C. and Xu, Wenwei and Wisser, Randall J.}, year={2023}, month={Feb} }
 @article{weldekidan_manching_choquette_leon_flint-garcia_holland_lauter_murray_xu_goodman_et al._2021, title={Registration of tropical populations of maize selected in parallel for early flowering time across the United States}, volume={10}, ISSN={["1940-3496"]}, url={https://doi.org/10.1002/plr2.20181}, DOI={10.1002/plr2.20181}, abstractNote={Abstract Tropical strains of maize ( Zea mays subsp. mays L.) flower very late in temperate environments. This is a barrier to maize diversification and improvement in regions where a large share of the world's corn production takes place. For investigating early flowering time adaptation, a tightly controlled parallel selection experiment spanning a 28° latitudinal range (∼3,100 km) across the United States was conducted. First, a tropical synthetic population (TropicS‐G0) (Reg. no. GP‐605, PI 698625) of maize was created from seven inbred parents. The molecular genetic diversity in TropicS‐G0 is representative of tropical inbreds that are differentiated from the prevailing germplasm used for hybrid production in the United States. Admixture analysis and genome simulation showed that breeding of TropicS‐G0 captured the parental genomes mostly at random, as intended prior to selection. With TropicS‐G0 as a common base population, a standardized protocol was used to recurrently select for early flowering time at eight locations for two generations, giving rise to location‐specific lineages (TropicS‐G1‐PR, Reg. no. GP‐621, PI 698641; TropicS‐G2‐PR, Reg. no. GP‐622, PI 698642; TropicS‐G2‐FL, Reg. no. GP‐620, PI 698640; TropicS‐G1‐cTX, Reg. no. GP‐618, PI 698638; TropicS‐G2‐cTX, Reg. no. GP‐619, PI 698639; TropicS‐G1‐nTX, Reg. no. GP‐616, PI 698636; TropicS‐G2‐nTX, Reg. no. GP‐617, PI 698637; TropicS‐G1‐NC, Reg. no. GP‐614, PI 698634; TropicS‐G2‐NC, Reg. no. GP‐615, PI 698635; TropicS‐G1‐DE, Reg. no. GP‐610, PI 698630; TropicS‐G1‐IA, Reg. no. GP‐608, PI 698628; TropicS‐G2‐IA, Reg. no. GP‐609, PI 698629; TropicS‐G1‐WI, Reg. no. GP‐606, PI 698626; TropicS‐G2‐WI, Reg. no. GP‐607, PI 698627). Additional generations of selection were performed for the DE lineage (TropicS‐G3‐DE, Reg. no. GP‐611, PI 698631; TropicS‐G4‐DE, Reg. no. GP‐612, PI 698632; TropicS‐G5‐DE, Reg. no. GP‐613, PI 698633). The parallel‐selected maize population is a novel resource for breeders and those seeking to investigate adaptation.}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Weldekidan, Teclemariam and Manching, Heather and Choquette, Nicole and Leon, Natalia and Flint-Garcia, Sherry and Holland, James and Lauter, Nick and Murray, Seth C. and Xu, Wenwei and Goodman, Major M. and et al.}, year={2021}, month={Oct} }