Bioenergy traits data of lowland switchgrass (Panicum virgatum L.) hybrid populations

Switchgrass (Panicum virgatum L.) is a potential source for producing bioenergy from lignocellulosic biomass. Many breeding programs focus on the genetic improvement of switchgrass for increasing bioenergy traits. Significant genetic variation for bioenergy traits was observed in lowland switchgrass hybrids (P<0.05). Due to the quantitative inheritance of bioenergy traits, varietal improvement for the trait through conventional methods is slow and challenging. Therefore, quantitative trait loci (QTL) mapping is used to discover marker-trait associations and accelerate the breeding process through marker-assisted selection. To identify significant QTL, this study mapped eight hybrid populations (30 to 96 F1s) developed by crossing lowland cultivars, Alamo and Kanlow. The populations were evaluated in a simulated-sward plot with two replications at two locations in Tennessee in 2020 and 2021. The crosses were genotyped using 17,251 single nucleotide polymorphisms generated through genotyping-by-sequencing. QTL mapping was performed across populations using R-QTL. The study identified ten QTL for predicted ethanol, four for cellulose, and three hemicellulose on chromosomes 1K, 1N, 2N, 4N, 5K, 5N, 7K, 8K, 8N, and 9N, respectively, with phenotypic variability ranged from 2.1 to 7.4%.

The dataset contains two comma-separated files (CSV) describing the phenotype of each individual used in the quantitative trait loci (QTL) analysis. The genotype data, including the number of SNPs and thier chromosomal locations, progeny file and linkage map, are provided in Shrestha et al. (2023).

‘File1.Phenotype_traits.csv’ contains bioenergy traits analyzed using Near-Infrared Reflectance Spectroscopy (NIRS) technique after plants reached to the physiological maturity. The traits include predicted ethanol (ETOH), cellulose, hemicellulose, glucose (GLC), sugar (SUG), klason lignin (KL), ash, p-coumarate esters (PCA), esterified ferulates (FEST), etherified ferulates (FETH), pentose sugars released per gram of dry forage (PENT), the proportion of hexoses that are non-structural or soluble (PSOL), pentose proportion of total carbohydrates (PPEN), theoretical ethanol from hexoses (HEXE), estimated ethanol from non-structural carbohydrates (NSCE), and cell wall ethanol (CWE) data for each genotype. The genotypes were evaluated in two replications at two locations in Tennessee; the Plateau Research and Education Center (PREC), Crossville and East Tennessee Research and Education Center (ETREC), Knoxville in 2020 and 2021. ETOH, cellulose, hemicellulose, GLC, SUG, KL, ash, PCA, FEST, FETH, PENT, HEXE, NSCE, and CWE were measured in mg/g and PSOL and PPEN were measured in %.

‘File 2.QTL_phenotype.csv’ provides averaged phenotype information for each genotype derived through the statistical analysis and was used as phenotype data in QTL mapping.