Miscanthus, a member of the Saccharinae subtribe that includes sorghum and sugarcane, has been widely studied as a feedstock for cellulosic biofuel production. Here, we report the sequencing and assembly of the Miscanthus floridulus genome by the integration of PacBio sequencing and Hi-C mapping, resulting in a chromosome-scale, high-quality reference genome of the genus Miscanthus. Comparisons among Saccharinae genomes suggest that Sorghum split first from the common ancestor of Saccharum and Miscanthus, which subsequently diverged from each other, with two successive whole-genome duplication events occurring independently in the Saccharum genus and one whole-genome duplication occurring in the Miscanthus genus. Fusion of two chromosomes occurred during rediploidization in M. floridulus and no significant subgenome dominance was observed. A survey of cellulose synthases (CesA) in M. floridulus revealed quite high expression of most CesA genes in growing stems, which is in agreement with the high cellulose content of this species. Resequencing and comparisons of 75 Miscanthus accessions suggest that M. lutarioriparius is genetically close to M. sacchariflorus and that M. floridulus is more distantly related to other species and is more genetically diverse. This study provides a valuable genomic resource for molecular breeding and improvement of Miscanthus and Saccharinae crops.

The world food demand is expected to double by 2050 and the availability and quality of irrigation water is declining because of the needs of the expanding population combined with the effects of climatic change. Therefore, productivity and water‐use efficiency (WUE) are crucial issues in the production of winter wheat (Triticum aestivum L.). The objective of this field study was to compare and evaluate the soil water characteristic, evapotranspiration (ET), yield, and yield components to identify possible ways to improve WUE of winter wheat in the North China Plain. The field experiment in a randomized complete block design with four replicates was conducted during 2008 to 2009 and 2009 to 2010. There were three planting patterns: traditional flat seedbed with uniform row spacing of 25 cm, wide–narrow row spacing of 40‐cm and 20‐cm flat seedbed and furrow‐ridge seedbed; three irrigation treatments: 90, 135, and 180 mm. The results showed that planting pattern and irrigation had significant effect on ET, yield components, grain yield, and WUE (P < 0.05); however, interaction between planting pattern and irrigation only had a significant effect on yield (P < 0.01). Compared with the conventional flat uniform planting pattern, the new treatment of furrow‐ridge seedbed planting pattern increased WUE by 13.7%, increased grain yield by 9.7%, reduced ET by 3.4%, increased soil water content (SWC) by 7.7%, increased soil water storage (SWS) by 6.8%, and increased yield components (grains per spike 15.0%, thousand‐grain weight [TGW] by 3.2%). Irrigation increased upper SWC, SWS, and ET, but decreased WUE. Compared with 90‐mm irrigation treatment, 135‐mm irrigation treatment increased grain yield by 6.4%. The findings suggest that application of the furrow‐ridge seedbed planting pattern combined with 135‐mm irrigation may be an effective strategy to improve winter wheat production in water‐scarce regions.

Lignocellulose content is an important factor affecting the conversion efficiency of biomass energy plants. In this study, 179 Miscanthus accessions in China were used to determine the content of lignocellulose components in stems via acid hydrolysis and high-performance liquid chromatography. Results showed that the average lignocellulose content of wild Miscanthus germplasm resources was 80.27

e objective of the study was to investigate the e ect of planting patterns and irrigation on radiation use e ciency and yield of winter wheat (Triticum aestivum L.) in northern China from 2008 to 2009 and 2009 to 2010. A factorial experiment consisting of three planting patterns: 25 cm uniform row planting pattern (U), "20 + 40" wide-narrow row planting pattern (wide row spacing [RS] of 40 cm and narrow RS of 20 cm, WN), and "20 + 40" furrow planting pattern (double lines in the furrow with 20 cm spacing, and 40 cm between furrows, ridge high 15 cm, F). ree irrigation treatments were 90, 135, and 180 mm. e leaf area index (LAI) of F planting was higher than that of U and WN under the same irrigation amount. e planting pattern of WN and F, especially the latter, signi cantly improved the photosynthetic active radiation capture ratio at 0 to 40 cm above the ground surface. Under the same irrigation amount, grain yields of F were signi cantly higher (P < 0.05) than those of U and WN planting patterns. With the increasing irrigation amount, grain yield of winter wheat was not signi cantly increased between 135 and 180 mm irrigation from 2009 to 2010 (P < 0.05). In conclusion, considering the water shortage, the F and 135 mm irrigation should be a good agronomic measure to increase grain yield.

Different cultivation patterns affect the grain yields of winter wheat by regulating growth and development. In this study, the growth of wheat was observed for two years (2008-2009 and 2009-2010). We established three cultivation patterns: 25 cm uniform row planting pattern; "20 cm + 40 cm" wide-narrow row planting pattern (wide-narrow row spacing is 40 cm and 20 cm respectively); and "20 cm + 40 cm" furrow planting pattern (double lines in the furrow with 20 cm spacing, 40 cm between furrows, and ridge height of 15 cm). Three irrigation treatments viz. 90, 135 and 180 mm were established. Results showed that furrow planting pattern improved the ratio of variable over maximum fluorescence (Fv/Fm).With increasing irrigation amount, Fv/Fm increased, the amplification declined, and the net photosynthetic rate in flag leaves increased. However, such effect was not obvious beyond the irrigation range stipulated. Therefore, we recommend the furrow planting pattern, which resulted in stable yield and 135 mm deficit irrigation as optimum considering the water shortage in the area.

Miscanthus lutarioriparius is a species of bioenergy crop unique to China. It is widely distributed in the south of China with high resistance to drought and salt stress. To date, the molecular mechanism of the adaption to drought stress in M. lutarioriparius is little known. In this study, RNA-seq technology was employed to analyze the transcriptome changes of diploid and tetraploid M. lutarioriparius after drought treatment. It was found that the number of differentially expressed genes in diploid M. lutarioriparius was much higher than tetraploid, whereas the tetraploid M. lutarioriparius may require fewer transcriptional changes. While the transcriptional changes in drought-tolerant tetraploid M. lutarioriparius are less than that of diploid, more known drought-tolerant pathways were significantly enriched than drought-sensitive diploid M. lutarioriparius. In addition, many drought-tolerance-related genes were constitutively and highly expressed in tetraploid under either normal condition or drought stress. These results together demonstrated that drought-tolerant tetraploid M. lutarioriparius, on the one hand, may preadapt to drought by constitutively overexpressing a series of drought-tolerant genes and, on the other hand, may adapt to drought by actively inducing other drought-tolerant-related pathways. Overall, this study could deepen our understanding of the molecular mechanism of drought-tolerance in bioenergy plants.

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