Abstract
BackgroundSwitchgrass (Panicum virgatum) is a herbaceous crop for the cellulosic biofuel feedstock development in the USA and Europe. As switchgrass is a naturally outcrossing species, accurate identification of selfed progeny is important to producing inbreds, which can be used in the production of heterotic hybrids. Development of a technically reliable, time-saving and easily used marker system is needed to quantify and characterize breeding origin of progeny plants of targeted parents.ResultsGenome-wide screening of 915 mapped microsatellite (simple sequence repeat, SSR) markers was conducted, and 842 (92.0%) produced clear and scorable bands on a pooled DNA sample of eight switchgrass varieties. A total of 166 primer pairs were selected on the basis of their relatively even distribution in switchgrass genome and PCR amplification quality on 16 tetraploid genotypes. Mean polymorphic information content value for the 166 markers was 0.810 ranging from 0.116 to 0.959. From them, a core set of 48 loci, which had been mapped on 17 linkage groups, was further tested and optimized to develop 24 sets of duplex markers. Most of (up to 87.5%) targeted, but non-allelic amplicons within each duplex were separated by more than 10-bp. Using the established duplex PCR protocol, selfing ratio (i.e., selfed/all progeny x100%) was identified as 0% for a randomly selected open-pollinated ‘Kanlow’ genotype grown in the field, 15.4% for 22 field-grown plants of bagged inflorescences, and 77.3% for a selected plant grown in a growth chamber.ConclusionsThe study developed a duplex SSR-based PCR protocol consisting of 48 markers, providing ample choices of non-tightly-linked loci in switchgrass whole genome, and representing a powerful, time-saving and easily used method for the identification of selfed progeny in switchgrass. The protocol should be a valuable tool in switchgrass breeding efforts.
Highlights
Switchgrass (Panicum virgatum) is a herbaceous crop for the cellulosic biofuel feedstock development in the USA and Europe
Screening and evaluation of genome-wide mapped simple sequence repeat (SSR) markers Of the 915 primer pairs (PPs) that were positioned on the published linkage maps [18,24], 842 (92.0%) produced clearly scorable bands with approximate sizes as reported previously [15,16,17,18,19]
From the 842 PPs, 166 well amplified SSR markers were selected due to their relatively high allele number (≥4) per locus. These markers were distributed on 18 linkage groups (LGs) and spanned 1751.4 cM (84.0% coverage) of the reference map [24]
Summary
Switchgrass (Panicum virgatum) is a herbaceous crop for the cellulosic biofuel feedstock development in the USA and Europe. Switchgrass (Panicum virgatum L.) is a C4 perennial grass native to the prairies of North America and being developed as a herbaceous crop for the biofuel feedstock production in the USA and Europe [1,2,3]. Development of inbred lines is potentially possible, which will produce single cross hybrid cultivars in switchgrass [8,9,10]. The approach for producing hybrid cultivars is not applied due to high costs associated with producing large quantities of switchgrass clones through tissue culture and transplanting the clones into field plantings for large scale seed production. Identification of selfed progeny, offers the potential for the development of switchgrass inbred lines to serve as parents of F1 hybrids. The proposed procedure has proven successful for large amounts of seed production in maize (Zea mays), likely applicable in switchgrass
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
