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Biofuels and bio-based products can be produced from a wide variety of herbaceous feedstocks. To supply enough biomass to meet the needs of a new bio-based economy, a suite of dedicated biomass species must be developed to accommodate a range of growing environments throughout the USA. Researchers from the US Department of Agriculture’s Agricultural Research Service (USDA-ARS) and collaborators associated with the USDA Regional Biomass Research Centers have made major progress in understanding the genetics of switchgrass, sorghum, and other grass species and have begun to use this knowledge to develop new cultivars with high yields and appropriate traits for efficient conversion to bio-based products. Plant geneticists and breeders have discovered genes that reduce recalcitrance for biochemical conversion to ethanol and drop-in fuels. Progress has also been made in finding genes that improve production under biotic and abiotic stress from diseases, pests, and climatic variations.

A better understanding of sugarcane (Saccharum spp.) genetic variability in agronomic performance will help optimize breeding and selection strategies. Vigor ratings and Brix data were collected from the 2009 and 2010 clones in the first clonal selection stage (stage I) of the Canal Point (CP) sugarcane cultivar development program. Stage I individual selection was based on disease resistance and on the product of vigor and Brix. Vigor ratings (from 1 to 9) from all clones and Brix of any clones with a vigor rating ≥6 were collected in the stage I fields and analyzed for relationships between vigor and Brix, for selection rate in each family (i.e., cross), and for their coefficients of variation (CV) within and among families. There was no correlation between vigor and Brix, suggesting that it would be feasible in stage I to select sugarcane clones with both high vigor and high Brix. Variability was high (CV = 59%) for both the number of planted clones and selection rates among families, and vigor (7.2%) ...

Background The definition of prosthesis-patient mismatch (PPM) remains to be refined to enhance its prognosis insight after SAVR, especially in obese patients. Purpose To test the prognostic impact of effective and predicted prosthetic orifice area (OA) according to body weight status after surgical aortic valve replacement (SAVR) for severe aortic stenosis (AS). Methods Between 2009 and 2016, we prospectively explored all consecutive patients referred to our Heart Valve Clinic for a first SAVR for severe AS. Indexed OA predicted from reference normal value (iPOA) and calculated by transthoracic echocardiography (iEOA) were assessed at discharge. Patients were followed for major events (ME), i.e. cardiovascular death, cardiac hospitalization for acute heart failure and stroke. Results 762 patients were included with a mean follow-up of 4 ± 2.5 years. Severe PPM was more frequently observed with iEOA than iPOA (20.5% vs. 7%, P Conclusion iEOA with the unique cut-off of 0.85 cm2/m2 showed the best accuracy to predict ME after SAVR in lean and overweight but not in obese patients. Further studies are needed to explore the lack of prognostic insight of PPM in obese patients.

Sugarcane (Saccharum spp.) is a successful crop in the Florida Everglades Agricultural Area (EAA) that is characterized by high-N organic and low-fertility sandy soils, periodic freeze, and flood events. After 50 yr of breeding, the possibility of a yield plateau was investigated in the cooperative Florida sugarcane breeding program via an assessment of yield gains in the industry and an evaluation of the contribution attributed to breeding efforts. Long-term commercial and selection trial data, covering a 33-yr period (1968-2000), were used in single-degree-of-freedom regression analyses to determine rates of improvement in sucrose content (SC; kg Mg -1 ), cane yield (CY; Mg ha -1 ), and sugar yield (SY; Mg ha -1 ). Analyses of commercial data reflected yearly increases of 0.80 ± 0.08 kg Mg -1 of cane for SC, 0.31 ± 0.10 Mg ha -1 for CY, and 0.10 ± 0.01 Mg ha -1 for SY. Corresponding gains from selection trial data were 0.74 ± 0.15 kg Mg -1 , 1.06 ± 0.40 Mg ha -1 , and 0.16 ± 0.05 Mg ha -1 , respectively. Improvements were significant for all three traits across plant-cane, and first- and second-ratoon crops grown on organic soils but not on sandy soils. About 69% of the total gain in SY was attributed to the cooperative Canal Point public breeding program, via a greater allocation of assimilates toward sucrose accumulation, resulting in a contribution of $99 to 203 million as additional profits to the Florida economy across the 33 yr. The genetic potential of the working germplasm has not been exhausted (no evidence of a yield plateau for SC) in this sugarcane breeding program. These gains and future advances are possible because of the use of a diverse gene pool and a breeding strategy that integrates growers' participation into the program.