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 #341944

Title: Quantitative trait loci mapping for flowering time in a switchgrass pseudo-F2 population

item TORNQVIST, CARL-ERIK - University Of Wisconsin
item TAYLOR, MEGAN - Purdue University
item JIANG, YIWEI - Purdue University
item EVANS, JOSEPH - Pioneer Hi-Bred, Inc
item BUELL, C ROBIN - Michigan State University
item KAEPPLER, SHAWN - University Of Wisconsin
item Casler, Michael

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/5/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Flowering is an important developmental event in switchgrass (Panicum virgatum) because the onset of flowering causes the cessation of vegetative growth and biomass accumulation. The objective of this study was to generate a linkage map using single nucleotide polymorphism (SNP) markers to identify quantitative trait loci (QTL) associated with flowering time. A pseudo-F2 population was created by crossing two F1 hybrid siblings that were derived from an initial cross between an upland and a lowland switchgrass cultivar. Phenotypic data on heading and anthesis dates were collected for 2 years at two locations: DeKalb, IL and West Lafayette, IN. Overall, six QTL for flowering time were detected, five of which were heading-associated and four were anthesis-associated. One QTL on linkage group (LG) 2a was detected for heading and anthesis in each separate analysis of location and year and in a combined analysis across both locations and years. The average effect on heading and anthesis of the QTL on LG 2a ranged from 5 to15 and 5 to 12 days, respectively, depending on the environment. One LG with detected QTL in this study matched a LG with detected QTL for reproductive maturity in switchgrass reported in a previous study. Thus, the findings here support previous findings on switchgrass flowering time QTL and identify additional QTL. Many flowering time orthologs reside on chromosome 2a, based on the switchgrass reference genome version 1.1. Examining the flowering time genes in proximity to the LG 2a QTL, one can speculate on putative candidate genes, which include PSEUDO RESPONSE REGULATOR 5, involved in coordinating photoperiod cues with the circadian clock, SUPPRESSOR OF FRIGIDA 4, a vernalization-related gene from Arabidopsis, and APETALA 1, a floral meristem identity gene. Markers linked to the QTL identified could be used to improve the efficiency of breeding switchgrass for delayed flowering to increase biomass yield.