Genome Size and Chromosome Analyses in Prairie Cordgrass (Spartina pectinata Link).

The next generation of bioenergy crops will be grown on marginal lands. Prairie cordgrass (Spartina pectinata Link) is well suited to marginal land because of its tolerance to stresses such as salinity and water fluctuations. Developing prairie cordgrass as a energy crop requires genomic information such as genomic size and ploidy level. The somatic G1 nuclear genome size of 11 prairie cordgrass populations, originating from Illinois, North Dakota, or South Dakota, were determined using flow cytometry, and the ploidy variation was confirm by counting the chromosome number. One population from each of North Dakota and South Dakota, as well as Red River had genome sizes of 3.1 pg of DNA per G1 somatic nucleus whereas, the majority of the eight populations from Illinois had a genome size of 1.6 pg.  One plant from one of the Illinois populations had an estimated genome size of 2.3 pg. These genome sizes of 3.1 pg and 1.6 pg, along with their respective chromosome numbers of 80 and 40 indicate octoploid and tetraploid plants. The chromosome number of 60 observed in the plant with 2.3 pg indicated that this plant was hexaploid. This study provides the first estimates of genome size for prairie cordgrass and is also the first to report observed hexaploidy in this species. This genomic information provides critical knowledge for designing efficient breeding schemes for plant improvement.