Photos from the 2003 East Tennessee Collegiate Division Meeting of the Tennessee Academy of Science held at Pellissippi State Technical Community College
4/11/2003
Josh Tummel, Maryville College
ABSTRACT
Study of Rhizobial Diversity from Four Different Sites in Venezuela Using DNA Extracted from Nodules
We have been studying the nodulation of various legumes crops at different sites in Venezuela. Our findings indicate that some crops can be nodulated at specific sites in the absence of applied inoculum. The present study was conducted to determine whether rhizobia that nodulate native legumes are responsible for the nodulation seen at these sites. Four field sites were sampled that differed primarily in their soil pH (pH=4.6 to 5.2). Vigna unguiculata and Cajamls cajan were planted at each site and were found to be nodulated in the absence of applied inoculum. Nodules were collected from these two plants species, as well as a number of native legume species growing wild in the area. The wild species included members of the following genera: Cassia, Desmodium, Mimosa, Zomia, and Indigofera. DNA was extracted directly from the isolated nodules and analyzed for purity using a UV spectrophotometer and agarose electrophoresis. Preliminary PCR results show that the DNA came from a variety of rhizobia.
