Long-term climate change and periodic environmental extremes threaten food and fuel security1 and global crop productivity2–4. Although molecular and adaptive breeding strategies can buffer the effects of climatic stress and improve crop resilience5, these approaches require sufficient knowledge of the genes that underlie productivity and adaptation6—knowledge that has been limited to a small number of well-studied model systems. Here we present the assembly and annotation of the large and complex genome of the polyploid bioenergy crop switchgrass (Panicum virgatum). Analysis of biomass and survival among 732 resequenced genotypes, which were grown across 10 common gardens that span 1,800 km of latitude, jointly revealed extensive genomic evidence of climate adaptation. Climate–gene–biomass associations were abundant but varied considerably among deeply diverged gene pools. Furthermore, we found that gene flow accelerated climate adaptation during the postglacial colonization of northern habitats through introgression of alleles from a pre-adapted northern gene pool. The polyploid nature of switchgrass also enhanced adaptive potential through the fractionation of gene function, as there was an increased level of heritable genetic diversity on the nondominant subgenome. In addition to investigating patterns of climate adaptation, the genome resources and gene–trait associations developed here provide breeders with the necessary tools to increase switchgrass yield for the sustainable production of bioenergy.

Fine fescues (Festuca L. spp.) comprise a group of five cool-season grasses used in turfgrass systems under many conditions: strong creeping red fescue (F. rubra L. ssp. rubra Gaudin), slender creeping red fescue [F. rubra L. ssp. littoralis (G. Mey.) Auquier], Chewings fescue [F. rubra L. ssp. commutata Gaudin; syn. F. rubra L. ssp. fallax (Thuill.) Nyman], hard fescue (F. brevipila Tracey), and sheep fescue [F. ovina L.; syn. F. ovina L. ssp. hirtula (Hack. ex Travis) M.J. Wilk.]. Their extensive geographic distribution is a result of adaptation to many different environmental and management conditions especially low-input sites. This review summarizes the history, production, establishment, management, use, and availability of fine fescues; discusses strengths and shortcomings of fine fescue; identifies knowledge gaps; and provides an outlook toward further research on this group of grasses. Improved cultivars have been developed in recent years that expand the geographic distribution and uses of species but additional efforts to increase seed yield and improve abiotic and biotic stress tolerances are still needed. Expanded use of fine fescue could be achieved through increased sod production of fine fescue, though current research-based information is limited. Research on fine fescue allelopathy and the contributions of fungal endophytes, both of which could lead to reduced pesticide requirements is important for improved pest management. Future research on fine fescues should focus on implementation and management of new cultivars that possess enhanced abiotic and biotic stress tolerance that will result in fewer inputs and improve the appeal and adoption of these low-input grasses.

Miscanthus 9 giganteus is a C 4 perennial grass that shows great potential as a high-yielding biomass crop. Scant research has been published that reports M. 9 giganteus growth and biomass yields in different environments in the United States. This study investigated the establishment success, plant growth, and dry biomass yield of M. 9 giganteus during its first three seasons at four locations (Urbana, IL; Lexington, KY; Mead, NE; Adelphia, NJ) in the United States. Three nitrogen rates (0, 60, and 120 kg ha À1 ) were applied at each location each year.Good survival of M. 9 giganteus during its first winter was observed at KY, NE, and NJ (79-100%), and poor survival at IL (25%), due to late planting and cold winter temperatures. Site soil conditions, and growing-season precipitation and temperature had the greatest impact on dry biomass yield between season 2 (2009)

Switchgrass (Panicum virgatum L.) is a warm season, C 4 perennial grass native to most of North America with numerous applications, including use as a bioenergy feedstock species. To date, no studies on genetic diversity in switchgrass have been conducted that use both molecular and morphological markers. The objectives of this study were to assess genetic diversity and determine differences among and between 12 switchgrass populations grown in New Jersey by examining both morphological and molecular characteristics, and to determine whether morphological, molecular, and/or combined data sets can detect ecotype and/or geographical differences at the population level. Twelve plants from each population were characterized with 16 switchgrass expressed sequence tag-simple sequence repeat markers (EST-SSRs) and seven morphological characters. Data was analyzed using GenAlEx and Unweighted Pair-Group Method of Averages (UPGMA) cluster analysis. Most (64%) of the molecular variation in switchgrass populations exists among individuals within populations, with lesser amounts between populations (36%). Upland and lowland populations were distinguished in all three data sets. Some eastern US and midwestern US populations were distinct in all three data sets. Similarities were observed between all three data sets indicating molecular markers may be useful for identifying morphological differences or other adaptive traits. The combined data set was the most useful in differentiating populations based on geography and found separation between midwestern and eastern upland populations. The results indicate that the combination of morphological and molecular markers may be useful in future applications such as genetic diversity studies, plant variety protection, cultivar identification, and/or identifying geographic origin.

Cultivars and selections of Kentucky bluegrass (Poa pratensis L.) exhibit varying degrees of summer stress tolerance. Understanding the factors associated with performance under summer stress is important for identifying stress tolerant germplasm. The objective of this field study was to evaluate shoot and root growth responses of 10 Kentucky bluegrass genotypes subjected to high temperature and drought stress conditions in New Jersey. Turf canopy characteristics, shoot and root growth responses, and soil water depletion patterns were evaluated on a Nixon Loam (fine‐loamy, mixed mesic Typic Hapludult) and used to characterize Kentucky bluegrass selections having variable summer stress tolerance. Tolerant entries maintained 19% more roots at the 15‐ to 30‐cm depth in 1995 and 65% more roots at the 30‐ to 45‐cm depth than intolerant entries. Gravimetric soil water contents of tolerant plots were significantly lower at the 15‐ to 30‐cm depth than intolerant entries for both years. Tolerant Kentucky bluegrass, able to exploit deep soil moisture under heat and drought conditions, exhibited significantly fewer summer stress symptoms, had significantly lower stomatal resistance (based on subset of cultivars), and maintained canopy temperature 5°C cooler than intolerant entries at the end of stress periods. This indicated that maintenance of transpirational cooling was an important factor associated with better summer stress performance of turf plots under high temperature and drought conditions in New Jersey.