The genus Salix,which comprises more than 300 species,is widespread in both Northern and Southern hemisphere,excluding Australasia and New Guinea.Many Salix species display rapid growth and high biomass yields,ease of establishment and wide range of adaptability,which makes it becoming a widely used species for biomass production in short-rotation intensive culture (SRIC) systems.Breeding willows that are adapted to different environments with high yield is an active demand for the biomass industry.However,conventional breeding programs is very time consuming due to the long life span of tree species,more efficient breeding meanings need to be developed for accelerating the domestication of wild willows.S.xuzhouensis is an annual flowering shrub willow,which is amenable for genetic manipulation.Especially,it is easy to carry out large scale field trial.It is a desirable species to uncover the genetic factors underlying the woody plants specific traits due to the short juvenile period,the small individual size and the moderate genome size.A genome-wide shotgun strategy incorporating Roche-454 and Illumina-Hiseq-2000 sequencing technologies were employed to sequence the genome of S.xuzhouensis.Totally,23.2 million 454-shotgun reads,5.4 million 454-paired end reads,700.0 million Illumina paired end reads corresponding to 131 Gb of sequence data were produced.Genome size of S.xuzhouensis was estimated to be 380-Mb,which was measured by a flow cytometry using Populus trichocarpa (~600 Mb) and P.euphratica (~650 Mb) as inner controls.Therefore,the obtained total sequence data covered ca.327.5 sequencing depth of the genome.Sequence assembly was performed with Newbler software version 2.7 (Roche,Inc.).Altogether,30,316 contigs and 5,923 scaffolds were produced,and 148 scaffolds covered 80% of the assembled sequences.The N50 (the scaffold size above which 50% of the total length of the sequence assembly can be found) was 1.6Mb and the largest scaffold spanned a physical length of 3.4 Mb.The current assembly encompassed of total length of 302.2 Mb,which represents ca.79.5% of the estimated genome size of the S.xuzhouensis genome.Since willow and poplars originate from the same ancestor.With genome sequences available both in willow and poplars,these important resources will play fundamental roles in the functional genomics studies for plants in Salicaceae family,and especially useful in uncovering the major genes that control the domestication traits for biomass production and wood formation both in willows and poplars.