Discipline: Biological Sciences
Margeria Smith - Alcorn State University
Co-Author(s): Keerthi Mandyam, Ananda Nanjundaswamy, and Victor Njiti, Alcorn State University
Cultivating dedicated energygrasses is vital in achieving annual biomass production of billion tons required by 2030 for fulfilling the U.S. bioenergy vision for energy independence. Energygrass Giant Miscanthus is perennial, C4 grass with low or no nitrogen fertilization demand and commercial varieties like Freedom have been bred for highest biomass yield in southeastern U.S. From an ecological perspective, the long-term and large-scale production of energygrass has prompted investigations into root-associated bacterial communities especially those involved in nitrogen cycling. However, C4 grasses are known to be obligately mycotrophic with high abundance of root fungal endophytes that play a role in facilitating nutrient uptake, enhancing host fitness and improving plant stress tolerance. Despite the significance of fungal symbiosis in C4 grasses, root fungal endophyte abundance of Giant Miscanthus has not been quantified. Accordingly, we hypothesized that Freedom Giant Miscanthus (FGM) will exhibit more than 90% root length colonization (RLC) by both, arbuscular mycorrhizal fungi (AMF) and dark septate endophytic (DSE) fungi, and both endophytes will exhibit seasonal, temporal and spatial variation in abundance as seen in other C4 grasses. FGM root samples were collected i) from four different plots in three different locations (Lorman, Mound Bayou, and Preston) in Mississippi, ii) four times a year coinciding with the seasons, and iii) annually in 2013, 2014, and 2015. Root samples were stained with trypan blue and sudan IV to visualize AMF and DSE respectively, and the percent RLC was recorded according to magnified intersections method. Our preliminary results indicate fungal abundance trend as hypothesized. By December, we will have obtained complete data for three years of FGM cultivation. Statistical analyses of our data will be discussed. This investigation will continue until 2017. The first four years of energygrass cultivation is the ‘stand establishment’ period and once established, stands last for 15-20 years. Since future large-scale biomass production will see the adoption of commercial, high biomass yielding, region-specific energygrass cultivars, data from this study will provide practical and valuable insights into fungal ecology and plant-fungal symbioses of a commercial energygrass variety.
Funder Acknowledgement(s): This study was funded in part by NSF HBCU-UP RIA to Keerthi Mandyam Ph.D, Department of Agriculture, Alcorn State University, Lorman, MS 39096
Faculty Advisor: Keerthi Mandyam,