Shaohong Qu and Guo-Liang Wang
Department of Plant Pathology, The Ohio State University, Columbus, OH 43210

Plant genomics is becoming a rapidly emerging field that holds the promise of providing new strategies for crop improvement. Large-insert genomic libraries are one of the key components in plant genomic research. These libraries can be used in a variety of projects such as map-based cloning of important genes, genome organization study, physical mapping of chromosomes and molecular breeding programs. To support Ohio plant molecular biologists' effort in gene cloning,  we are going to make four transformation-competent artificial chromosome (TAC) libraries of soybean, tomato, corn and turfgrass. The cultivars for making the libraries are widely grown by farmer or commonly used by many researchers in Ohio. These locally adapted cultivars have many desirable traits and are being used in breeding programs as parental lines. We have made a new TAC vector with hygromycin selection marker, which is being widely used in transformation of monocots and dicots. The vector was purified and tested for ligation with different DNA samples. A 65-kb rice genomic DNA fragment was successfully cloned into the vector. High quality of high molecular weight DNA was isolated from tomato, soybean and turf.  Preparation of partially digested tomato DNA is in progress. The libraries made in this project will offer the particular advantage of allowing direct transformation into plants to facilitate the identification of gene function.