The 2012 ASHS Annual Conference

Bioethanol can be obtained from grains or cellulosic biomass. It has been known that switchgrass, which is a lignocellulose source can become a potential cheap, renewable biomass material to produce bioethanol. The amount and quality of switchgrass leaf biomass are determined not only by the ontogenetic processes within the leaf, but also are known to be affected by environmental conditions. In this experiment, we first investigated the growth habits of switchgrass ‘alamo’ under different stress (drought and salt treatment) conditions during leaf emergence. Each treatment cycle was administered for 5–10 days. We recorded changes in root length before and after the treatments, and observed roots’ growing region. According to the data, our primary results showed that the root growth primarily occurs at the very tips. For the salt treated plants, total ceasation of root growth was observed, while for the drought treated ones, root growth was observed until the plant experienced complete water scarcity. Second, we investigated the mutagenesis of switchgrass. We treated the seeds with sodium azide and EMS (Ethyl Methan Sulfonate), calculated the germination rate after treatments, and tried to find mutant individuals which have resistance to stress environment. Switchgrass ‘foxtail’ seeds were soaked in distilled water over night and then were dipped in 2% and 4% phosphate buffer solution of EMS for 8 hours. Another batch of ‘alamo’ seeds were soaked in distilled water over night and then treated with 5 mM, 10 mM, 20 mM oxygenated sodium azide for the following durations: 1 hrs, 2 hrs, 4 hrs, respectively. The results showed that the best condition for sodium azide mutagenesis for alamo was at 10 mM for 4 hrs, which resulted in a 50% germination rate. As for the EMS mutagenesis, better condition came at 2% for 8 hrs treatment, which got a 40% germination rate. Our identification of mutant individuals is still in progress and we will futher study how the root apex growth affects the plants emergence, vegetative growth, maturation and senescence, especially under stress conditions.