Project Number: 6202-21000-028-01
Project Type: Specific Cooperative Agreement

Start Date: Sep 01, 2005
End Date: Aug 31, 2010

Objective:
The objective of this cooperative research project is to determine the nuclear DNA content of different grass species to provide a better understanding of their genome evolution, chromosome organization, and ploidy levels (polyploidy) as well as provide information beneficial for structural genomics.

Approach:
Germplasm representing a wide range of accessions of different grass species (Florida paspalum, dallisgrass, brown seeded paspalum, bahiagrass, buffelgrass, etc.) will be collected and analyzed. The DNA content of each accession within a selected species will be determined using flow cytometry. DNA content in the nuclei of the select plants will be measured by laser flow cytometry and ultra-violet flow cytometry using different fluorescent stains (propidium iodide [PI] and 4¿, 6-diamidino-2-phenylindole [DAPI]). The DNA content of target species will be determined by comparing their mean fluorescences to that of established standards. The calculated values will be used to assess divergence within and among species involving both duplication of chromosomes (ploidy) and amplification or deletion of sequences within chromosomes. This information will provide insight into the evolutionary relationships of these species which is beneficial in selecting germplasm to use in the breeding of improved cultivars. DNA quantification is also of value in reconciling genetic vs. physical maps in genomic studies.