Skip to main content
ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Dairy Forage Research » Research » Publications at this Location » Publication #351140
Title: Genome-Wide association study in pseudo-F2 populations of switchgrass identifies genetic loci affecting heading and anthesis dates

Author
item TAYLOR, MEGAN - Purdue University
item TORNQVIST, CARL-ERIK - University Of Wisconsin
item ZHAO, ZIONGWEI - Purdue University
item GRABOWSKI, PAUL - University Of Texas
item DOERGE, REBECCA - Purdue University
item MA, JIANXIN - Purdue University
item VOLENEC, JEFF - Purdue University
item BUELL, C - Michigan State University
item Casler, Michael
item JIANG, YIWEI - Purdue University

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/6/2018
Publication Date: 9/13/2018
Citation: Taylor, M., Tornqvist, C., Zhao, Z., Grabowski, P., Doerge, R., Ma, J., Volenec, J., Buell, C.R., Casler, M.D., Jiang, Y. 2018. Genome-Wide association study in pseudo-F2 populations of switchgrass identifies genetic loci affecting heading and anthesis dates. Frontiers in Plant Science. https://doi.org/10.3389/fpls.2018.01250.
DOI: https://doi.org/10.3389/fpls.2018.01250

Interpretive Summary: Numerous breeding programs are working to develop switchgrass as a dedicated biomass crop for conversion to bioenergy. Many of these programs are focused on delaying flowering of the crop. This would allow the crop to more fully utilize the entire growing season, as a mechanism of increasing biomass yields. Molecular (DNA) markers would streamline the process of developing late-flowering populations of switchgrass which would increase the rate of progress toward this goal. This study identified five distinct segments of DNA that appear to be responsible for a large amount of variation in flowering time in a broad population of switchgrass hybrids because they lie within genes that regulate flowering time. These markers will help breeding programs that are developing late-flowering populations of this plant.

Technical Abstract: Switchgrass is a native prairie grass that has shown potential as a valuable bio-energy crop. The physiological change from juvenile to reproductive adult can draw important resources away from growth into producing reproductive structures, thus limiting the growth potential of early flowering plants. Delaying the flowering of switchgrass could increase the total biomass. The objective of this research was to identify genetic variations and candidate genes for controlling heading and anthesis in segregating switchgrass populations. Four segregating populations were developed from lowland (late flowering) and upland (early flowering) ecotypes and heading and anthesis dates of these populations were collected in Lafayette, IN and DeKalb, IL in 2015 and 2016, respectively. Across two years, there was a 34 and 73 day difference in heading and a 52 and 75 day difference in anthesis at the Lafayette and DeKalb locations, respectively. A total of 37,901 single nucleotide polymorphisms were obtained from 586 individuals from the populations by exome capture sequencing. A genome wide association study identified five significant signals at multiple loci including three for heading and two for anthesis. Among them, a homolog of FT (FLOWERING LOCUS T) on chromosome 5B associated with heading date was found at the Lafayette location across two years. A homolog of APRR5 (ARABIDOPSIS PSEUDO RESPONSE REGULATOR 5), a light modulator in the circadian clock associated with heading date was detected on chromosome 8A across locations and years. Identification of genetic variants related to floral development could assist in developing late flowering varieties of switchgrass with high biomass yield.