Kentucky bluegrass (Poa pratensis L.) is a prominent turfgrass in the cool-season regions, but it is sensitive to salt stress. Previously, a relatively salt tolerant Kentucky bluegrass accession was identified that maintained green colour under consistent salt applications. In this study, a transcriptome study between the tolerant (PI 372742) accession and a salt susceptible (PI 368233) accession was conducted, under control and salt treatments, and in shoot and root tissues. Sample replicates grouped tightly by tissue and treatment, and fewer differentially expressed transcripts were detected in the tolerant PI 372742 samples compared to the susceptible PI 368233 samples, and in root tissues compared to shoot tissues. A de novo assembly resulted in 388,764 transcripts, with 36,587 detected as differentially expressed. Approximately 75 % of transcripts had homology based annotations, with several differences in GO terms enriched between the PI 368233 and PI 372742 samples. Gene expression profiling identified salt-responsive gene families that were consistently down-regulated in PI 372742 and unlikely to contribute to salt tolerance in Kentucky bluegrass. Gene expression profiling also identified sets of transcripts relating to transcription factors, ion and water transport genes, and oxidation-reduction process genes with likely roles in salt tolerance. The transcript assembly represents the first such assembly in the highly polyploidy, facultative apomictic Kentucky bluegrass. The transcripts identified provide genetic information on how this plant responds to and tolerates salt stress in both shoot and root tissues, and can be used for further genetic testing and introgression.

Species from the crested wheatgrass (Agropyron spp.) complex have been widely used for revegetation and grazing on North American rangelands for over 100 years. Focused crested wheatgrass breeding has been ongoing since the 1920s. These efforts resulted in the development of 18 cultivars adapted to western USA and Canadian growing conditions. These cultivars establish rapidly, persist, and provide soil stabilization and a reliable feed source for domestic livestock and wildlife. To address ecological concerns and increase rangeland agriculture efficiency, crested wheatgrass breeding requires new emphases and techniques. This review covers the history of crested wheatgrass breeding and genetics in North America and discusses emerging methods and practices for improvement in the future.