Search for: All records

Abstract Poa pratensis, commonly known as Kentucky bluegrass, is a popular cool-season grass species used as turf in lawns and recreation areas globally. Despite its substantial economic value, a reference genome had not previously been assembled due to the genome’s relatively large size and biological complexity that includes apomixis, polyploidy, and interspecific hybridization. We report here a fortuitous de novo assembly and annotation of a P. pratensis genome. Instead of sequencing the genome of a C4 grass, we accidentally sampled and sequenced tissue from a weedy P. pratensis whose stolon was intertwined with that of the C4 grass. The draft assembly consists of 6.09 Gbp with an N50 scaffold length of 65.1 Mbp, and a total of 118 scaffolds, generated using PacBio long reads and Bionano optical map technology. We annotated 256K gene models and found 58% of the genome to be composed of transposable elements. To demonstrate the applicability of the reference genome, we evaluated population structure and estimated genetic diversity in P. pratensis collected from three North American prairies, two in Manitoba, Canada and one in Colorado, USA. Our results support previous studies that found high genetic diversity and population structure within the species. The reference genome and annotation will be an important resource for turfgrass breeding and study of bluegrasses. 

Societal Impact StatementThe current rate of global biodiversity loss creates a pressing need to increase efficiency and throughput of extinction risk assessments in plants. We must assess as many plant species as possible, working with imperfect knowledge, to address the habitat loss and extinction threats of the Anthropocene. Using the biodiversity database, Botanical Information and Ecology Network (BIEN), and the Andropogoneae grass tribe as a case study, we demonstrate that large‐scale, preliminary conservation assessments can play a fundamental role in accelerating plant conservation pipelines and setting priorities for more in‐depth investigations. SummaryThe International Union for the Conservation of Nature (IUCN) Red List criteria are widely used to determine extinction risks of plant and animal life. Here, we used The Red List's criterion B, Geographic Range Size, to provide preliminary conservation assessments of the members of a large tribe of grasses, the Andropogoneae, with ~1100 species, including maize, sorghum, and sugarcane and their wild relatives.We used georeferenced occurrence data from the Botanical Information and Ecology Network (BIEN) and automated individual species assessments using ConR to demonstrate efficacy and accuracy in using time‐saving tools for conservation research. We validated our results with those from the IUCN‐recommended assessment tool, GeoCAT.We discovered a remarkably large gap in digitized information, with slightly more than 50% of the Andropogoneae lacking sufficient information for assessment. ConR and GeoCAT largely agree on which taxa are of least concern (>90%) or possibly threatened (<10%), highlighting that automating assessments with ConR is a viable strategy for preliminary conservation assessments of large plant groups. Results for crop wild relatives are similar to those for the entire dataset.Increasing digitization and collection needs to be a high priority. Available rapid assessment tools can then be used to identify species that warrant more comprehensive investigation. 

ABSTRACT AimStudies assessing large‐scale patterns of microbial diversity have predominantly focused on free‐living microorganisms, often failing to link observed patterns to established theories regarding the maintenance of global diversity patterns. We aimed to determine whether foliar fungi on two closely related grass hosts—Heteropogon contortusandThemeda triandra—display a commonly observed latitudinal gradient in species richness and determine whether host identity, energy (temperature and precipitation), climate seasonality, fire frequency and grass evolutionary history drive the observed patterns in species richness and composition. LocationPaleotropical. Time PeriodContemporary. Major Taxa StudiedFoliar fungi. MethodsFoliar fungal diversity was quantified from 201 leaf samples ofT. triandraandH. contortuscollected across the distributional range of these species. Mixed effects models were used to quantify patterns of diversity and their correlates among and within continents. Ordinations were used to assess drivers of composition. ResultsFoliar fungi displayed consistent latitudinal diversity gradients in richness. Energy was a strong driver of richness at inter‐continental and continental scales, while other factors had inconsistent impacts on richness among scales, hosts and guilds. Globally, richness was higher in regions of higher growing season temperatures and where hosts were present for longer periods. Composition was primarily structured by geographic region at the global scale, indicating that distance was a dominant driver of community composition. Within Australia, temperature and rainfall seasonality and the amount of growing season rainfall, were the dominant drivers of both richness and composition. Main ConclusionsWe find some support for the idea that foliar fungal species diversity is governed by the same factors as many macro‐organisms (energy availability and evolutionary history) at inter‐continental scales, but also that fungal diversity and composition in the highly seasonal continent of Australia were driven by factors that shape tropical grassy ecosystems, namely climate seasonality and fire.