ASA Southern Branch 2008 Annual Meeting
February 3-5, 2008
Dallas, TX
Monday, February 4, 2008 - 3:50 PM
Phosphorus Acquisition by Duo Grass (Duo festulolium ) is Enhanced in the Presence of Various P- Sources in the Growth Media.
Priya Padmanabhan1, Kenneth Sajwan2, and Shivendra Sahi1. (1) Biology, Western Kentucky University, 1906 College Height Blvd # 11080, Bowling Green, KY 42101, (2) Savannah State University, Dept. of Natural Sci. & Mathematics, Savannah State Univ PO Box 20600, Savannah, GA 31404
Phosphorus (P) is an essential mineral nutrient for the growth and development of plants. A major part of soil P exists as organic P which is only poorly available to the plants. Further, application of P-based fertilizers and animal manures to the soil to increase P availability also result in enhanced P level often leading to the accelerated loss of P to water bodies through runoffs. Recently, the use of various crop plants and forages to extract P from soil at an enhanced rate is an emerging strategy of P remediation. Among the various grasses, Duo grass (Duo festulolium), a hybrid of meadow fescue and ryegrass showed promise as a hyperaccumulator of P. Approximately 1 % P was accumulated in the shoots of Duo grass from P-enriched soil under green house conditions. Enhanced P accumulation potential was observed when the grass was grown in the presence of different concentrations (0-7.5 mM) of KH2PO4 and inositol hexaphosphate (IHP) as P substrates in hydroponic conditions in different time intervals. Results of phytase as well as acid phosphatase enzyme assay also revealed elevated enzyme activity in the roots of grasses compared to the control (noP). In general, the enzyme activities were greatly enhanced in response to the increasing concentration of P substrates in the nutrient media. Biomass also increased significantly in the presence of KH2PO4 as well as IHP as P source.