Measuring genetic diversity of Texas bluegrass and allele sharing with Kentucky bluegrass interspecific hybrids using...

Kentucky bluegrass is an important cool-season turfgrass species. However, heat and drought tolerance is an issue. Interspecific hybridization with a related species, Texas bluegrass, is an approach used to improve heat and drought tolerance. We report herein a contig assembly and annotation of Texas bluegrass that was completed and used to measure the population structure of Texas bluegrass, interspecific lines between Texas and Kentucky bluegrass, and the percent allele sharing between advanced interspecific lines and cultivars to Texas bluegrass. The contig assembly was comprised of 367 contigs and spanned 6.6 Gb with 198,746 predicted gene models and an assembly and transcriptome completeness of over 97% as indicated by BUSCO orthologous gene alignment. It was used to call 14,504 high-quality SNPs. A principal component analysis showed separation of populations across the first 3 PCs, explaining 21.5, 11.1, and 5.4%, respectively, of the variation across the populations. Advanced interspecific lines and cultivars diverged from Texas bluegrass while sharing 62-74% of their alleles with Texas bluegrass. Interspecific Texas × Kentucky bluegrasses could be important for improving heat and drought tolerance among bluegrasses.