Genetic Variation for Ethanol Content Among ‘Kanlow' Half-Sib Population.

Switchgrass (Panicum virgatum L.) is widely recognized herbaceous feedstock for biofuel production. ‘Kanlow’ is a lowland type switchgrass which has high biomass yield potential in the northern zone of the southern plain. The objective of this study was to evaluate genetic variation for ethanol content among 54 half-sib families of Kanlow. The half-sib families were planted at two Tennessee locations, Knoxville and Crossville. The field experiment was planted in fall 2012, using a randomized complete block design with 3 replications. Each family in each replication was a single-row-plot comprised of 9 plants with 30 cm spacing between plants, and 90 cm between rows. Plant samples were collected at harvesting in 2013 and 2014 for assessment of feedstock composition. The samples were ground to pass through 1 millimeter mesh and quality data were generated by scanning ground samples in near-infrared (NIR) spectroscopy system. Cellulose and hemi-cellulose content derived from NIR analysis were used to calculate ethanol content. A significant variation for ethanol content was observed among half-sib families (P<0.001). Ethanol content among half-sib family varied from 229 LMt^-1 to 256 LMt^-1 in 2013 and 248 LMt^-1 to 265 LMt^-1 in 2014 at Knoxville location. Similarly, ethanol content ranged from 238 LMt^-1 to 252 LMt^-1 in 2013 and 237 LMt^-1 to 255 LMt^-1 in 2014 at Crossville location. Samples of half-sib families from Knoxville location tend to have higher ethanol content as compared to Crossville location. The results suggest that high genetic variability exists for ethanol content among Kanlow population and genetic gains could be achieved by exploiting additive genetic variance for ethanol content and associated quality traits.