Biomass crops have potential as a source of renewable CO2-neutral energy to ease concerns about fossil fuel consumption. Therefore, there is an increasing interest in high biomass crops such as switchgrass (Panicum virgatum L.). Switchgrass is a perennial C4 grass that requires low cost for biomass production. In the previous study, we evaluated forty-six switchgrass germplasms for biomass yield and classified the germplasms into the high-, medium-, and low-yielding groups. In this experiment, we analyze physiological characteristics affecting biomass productivity and composition of organic compounds for the two selected lines from each biomass yield group. Among the characteristics related to carbon assimilation, photosynthetic rate, real CO2 absorption rate(Delta CO2(CO2 reference - CO2 analysis(corrected for dilution))), P.A.R incident on leaf surface, and chlorophyll content were positively related to biomass yield of the selected lines. Positive correlation was found between biomass yield and ash content but no relations were found between biomass yield and content of organic compounds such as lignin, glucose, crude protein, cellulose, holocellulose, hemicellulose, ADF, and NDF. This study was supported by Technology Development Program for New Bioenergy(subject number-20070301030016), Rural Development Adiministration, Republic of Korea.

• Gee-Suck Eu(College of Agricultural and Life Sciences, Chonbuk National University)
• Ill-Min Chung(College of Life and Environmental Sciences, Konkuk University)
• Song Joong Yun(College of Agricultural and Life Sciences, Chonbuk National University, Experimental Farm, Chonbuk National University) Corresponding Author