The Genetic Basis of Upland/Lowland Ecotype Divergence in Switchgrass (Panicum virgatum)
نویسندگان
چکیده
The evolution of locally adapted ecotypes is a common phenomenon that generates diversity within plant species. However, we know surprisingly little about the genetic mechanisms underlying the locally adapted traits involved in ecotype formation. The genetic architecture underlying locally adapted traits dictates how an organism will respond to environmental selection pressures and has major implications for evolutionary ecology, conservation, and crop breeding. To understand the genetic architecture underlying the divergence of switchgrass (Panicum virgatum) ecotypes, we constructed a genetic mapping population through a four-way outbred cross between two northern upland and two southern lowland accessions. Trait segregation in this mapping population was largely consistent with multiple independent loci controlling the suite of traits that characterizes ecotype divergence. We assembled a joint linkage map using ddRADseq and mapped quantitative trait loci (QTL) for traits that are divergent between ecotypes, including flowering time, plant size, physiological processes, and disease resistance. Overall, we found that most QTL had small to intermediate effects. While we identified colocalizing QTLs for multiple traits, we did not find any large-effect QTLs that clearly controlled multiple traits through pleiotropy or tight physical linkage. These results indicate that ecologically important traits in switchgrass have a complex genetic basis and that similar loci may underlie divergence across the geographic range of the ecotypes.
منابع مشابه
Genetic diversity in tetraploid switchgrass revealed by AFLP marker polymorphisms.
Switchgrass (Panicum virgatum) is a perennial warm-season grass native to North America that has been identified as a dedicated cellulosic biofuel crop. We quantified genetic diversity in tetraploid switchgrass germplasm collected at Oklahoma State University and characterized genetic relatedness among the collections from distinct regions. Fifty-six tetraploid accessions, including seven...
متن کاملChloroplast Genome Variation in Upland and Lowland Switchgrass
Switchgrass (Panicum virgatum L.) exists at multiple ploidies and two phenotypically distinct ecotypes. To facilitate interploidal comparisons and to understand the extent of sequence variation within existing breeding pools, two complete switchgrass chloroplast genomes were sequenced from individuals representative of the upland and lowland ecotypes. The results demonstrated a very high degree...
متن کاملSwitchgrass Germplasm Resources
Switchgrass (Panicum virgatum L.) is an important native grass and dominant member of the tallgrass prairie ecosystem. It is used for conservation, restoration, livestock feed production, and bioenergy feedstock production. The purpose of this review is to describe the biological and geographical basis for switchgrass germplasm diversity and to provide a resource for scientists and outreach per...
متن کاملSwitchgrass Cultivar/Ecotype Selection and Management for Biofuels in the Upper Southeast USA
Switchgrass (Panicum virgatum L.), a perennial warm-season grass indigenous to the eastern USA, has potential as a biofuels feedstock. The objective of this study was to investigate the performance of upland and lowland switchgrass cultivars under different environments and management treatments. Four cultivars of switchgrass were evaluated from 2000 to 2001 under two management regimes in plot...
متن کاملDevelopmental morphology, biomass yield and compositional differences among upland and lowland switchgrass (Panicum virgatum L.) ecotypes grown as a bioenergy feedstock crop
Sustainable and successful development of the bioenergy industry strongly depends upon the amount and quality of bioenergy feedstock produced. Switchgrass (Panicum virgatum L.) has been identified as a model lignocellulosic bioenergy crop in the U.S. Information regarding its growth and development is considered critical for making management decisions, production of high quality feedstock and ...
متن کامل