Project description:Rhododendron hybridum Hort. (Ericaceae) is an important ornamental species with striking continuous flowering feature. However, few genomic resources are currently available in this species, and the breeding programs were handicapped by the lack of basic genetic information. Here, we established a transcriptomic profiling study from four different tissues using RNA-Seq to gain insight on the functional genes and to isolate EST-SSR markers for breeding and conservation purposes. In total 38,050,296 high-quality sequence reads were obtained, and 56,120 unigenes (with N50 = 1,236bp) were assembled. Of which, 32,580 (58.05 %) and 8,788 (15.66 %) were annotated to GO and KEGG database, respectively. Additionally, 38,775 (69.09 %) and 37,409 (66.66 %) R. hybridum unigenes were aligned to the Arabidopsis thaliana and Oryza sativa genome, respectively. A total of 21,103 simple sequence repeat (SSR) motifs were identified in 15,050 contigs. Among them, dinucleotide repeats account for the largest proportion for 49.27%, followed by mono- (35.94%) and trinucleotide (21.5%). This study represents the first transcriptome data of R. hybridum and confirms that the transcriptome assembly data are a useful resource for EST-SSR loci development. Such vast sequence data and markers will be robust tools for genomic research and breeding of R. hybridum and related species.
Project description:Many crop species have polyploid genomes that are unlikely to be sequenced to a high standard in the near future, representing a barrier to genomics-based breeding. As an exemplar, we sequenced the leaf transcriptome to analyse both sequence variation1 and transcript abundance across a mapping population of oilseed rape (Brassica napus), together with representatives of ancestors of the parents of the population. Twin SNP linkage maps were constructed, comprising 23,037 markers in all. These were used to analyse the genome for alignment to that of a related species, Arabidopsis thaliana, and to genome sequence assemblies of the progenitor species of B. napus. Methods were developed that enabled us to detect genome rearrangements and track inheritance of genomic segments, including the outcome of an inter-specific cross. This transformative advance, enabling economical high-resolution dissection of the genomes of most, if not all, crop species, will enable us to understand the genetic consequences of breeding and domestication, and will underpin the development of efficient predictive breeding strategies.
