Crataegus hupehensis Sarg. is well-known for its medicinal and nutritive value. In this study, the complete chloroplast genome sequence of C. hupehensis was determined by using Illumina high-throughput sequencing approach. The complete chloroplast genome is 159,766 bp with 36.6% GC content. It contained a pair of inverted repeat regions of 26,385 bp, a large single-copy region of 87,852 bp, and a small single-copy region of 19,144 bp. It contained 112 distinct genes, including 78 protein-coding genes, 4 ribosomal RNA genes, and 30 transfer RNA genes. Phylogenetic analysis based on chloroplast genomes indicated that C. hupehensisis was closely related to C. kansuensis and C. marshallii in the subfamily Maloideae. This complete chloroplast genome will provide valuable insight into evolution, molecular breeding, and phylogenetic analysis of Crataegus species.
Diospyros lotus L. (Date plum) is an important tree species that produces fruit with a high nutritional value. An accurate chromosomal assembly of a species facilitates research on chromosomal evolution and functional gene mapping. In this study, we assembled the first chromosome-level genomes of seeded and seedless D. lotus using Illumina short reads, PacBio long reads, and Hi-C technology. The assembled genomes comprising 15 chromosomes were 617.66 and 647.31 Mb in size, with a scaffold N50 of 40.72 and 42.67 Mb for the seedless and seeded D. lotus, respectively. A BUSCO analysis revealed that the seedless and seeded D. lotus genomes were 91.53% and 91.60% complete, respectively. Additionally, 20,689 (95.4%) and 22,844 (98.5%) protein-coding genes in the seedless and seeded D. lotus genomes were annotated, respectively. Comparisons of the chromosomes between genomes revealed inversions and translocations on chromosome 8 and inversions on chromosome 11. We identified 490 and 424 gene families that expanded in the seedless and seeded D. lotus, respectively. The enriched pathways among these gene families included the estrogen signaling pathway, the MAPK signaling pathway, and biosynthetic pathways for flavonoids, monoterpenoids, and glucosinolates. Moreover, we constructed the first Diospyros genome database (http://www.persimmongenome.cn). On the basis of our data, we developed the first high-quality annotated D. lotus reference genomes, which will be useful for genomic studies on persimmon and for clarifying the molecular mechanisms underlying important traits. Comparisons between the seeded and seedless D. lotus genomes may also elucidate the molecular basis of seedlessness.
Crataegus bretschneideri Schneid., with an unclear phylogenic position, is mainly distributed in northeast and inner mongolia area of China. In this study, the complete chloroplast genome sequence of C. bretschneideri was determined by using Illumina high-throughput sequencing method. The chloroplast genome was 159,607 bp in length and consisted of a large single-copy (LSC) region (87,601 bp), a small single-copy (SSC) region (19,312 bp), separated by a pair of inverted repeat (IRs: 26,347 bp, each) regions. It comprised a total of 114 unique genes, including 80 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. Phylogenetic analysis based on complete chloroplast genomes indicated that C. bretschneideri was closely related to C. marshallii Eggl in the subfamily Maloideae. This complete chloroplast genome will provide valuable insight into evolution, molecular breeding, and phylogenetic analysis of Crataegus species.