The Complete Chloroplast Genome Sequences of Fritillaria ussuriensis Maxim. and Fritillaria cirrhosa D. Don, and Comparative Analysis with Other Fritillaria Species.

The genus Fritillaria belongs to the widely distributed Liliaceae. The bulbs of Fritillaria, F. ussuriensis and F. cirrhosa are valuable herbaceous medicinal ingredients. However, they are still used indiscriminately in herbal medicine. Identification and molecular phylogenic analysis of Fritillaria species are therefore required. Here, we report the complete chloroplast (CP) genome sequences of F. ussuriensis and F. cirrhosa. The two Fritillaria CP genomes were 151,524 and 151,083 bp in length, respectively, and each included a pair of inverted repeated regions (52,678 and 52,156 bp) that was separated by a large single copy region (81,732 and 81,390 bp), and a small single copy region (17,114 and 17,537 bp). A total of 111 genes in F. ussuriensis and 112 in F. cirrhosa comprised 77 protein-coding regions in F. ussuriensis and 78 in F. cirrhosa, 30 transfer RNA (tRNA) genes, and four ribosomal RNA (rRNA) genes. The gene order, content, and orientation of the two Fritillaria CP genomes exhibited the general structure of flowering plants, and were similar to those of other Fritillaria species. Comparison of the six Fritillaria species' CP genomes indicated seven highly divergent regions in intergenic spacers and in the matK, rpoC1, rpoC2, ycf1, ycf2, ndhD, and ndhF coding regions. We established the position of the six species through phylogenic analysis. The complete chloroplast genome sequences of the two Fritillaria species and a comparison study are useful genomic information for identifying and for studying the phylogenetic relationship among Fritillaria species within the Liliaceae.

Genotyping by Sequencing (GBS)-Based QTL Mapping for Bacterial Fruit Blotch (BFB) in Watermelon.

Watermelon (Citrullus lanatus), an economically important and nutritionally rich Cucurbitaceous crop grown worldwide, is severely affected by bacterial fruit blotch (BFB). Development of resistant cultivar is the most eco-friendly, cost-effective, and sustainable way to tackle this disease. This requires wider understanding of the genetics of resistance to BFB. In this study, we identified quantitative trait loci (QTLs) associated with BFB resistance in an F2 mapping population developed from BFB-resistant 'PI 189225' (Citrullus amarus) and -susceptible 'SW 26' (C. lanatus) genotypes based on the polymorphic markers identified by genotyping by sequencing (GSB). A linkage map covering a total genetic distance of 3377.1 cM was constructed. Two QTLs for BFB resistance, namely, ClBFB10.1 and ClBFB10.2, both located on chromosome 10 explaining 18.84 and 15.41% of the phenotypic variations, respectively, were identified. Two SNP-based high-resolution melting (HRM) markers WmBFB10.1 and WmBFB10.2 having high positive correlation with resistance vs. susceptible alleles were developed. The efficacy of the markers was validated in another F2 population derived from SW34 × PI 189225. The highest phenotypic variation was found in the locus ClBFB10.2, which also contains three putative candidate genes for resistance to BFB. These findings will accelerate the development of BFB-resistant watermelon varieties via molecular breeding.

The complete chloroplast genome sequence of Aconitum coreanum and Aconitum carmichaelii and comparative analysis with other Aconitum species.

Aconitum species (belonging to the Ranunculaceae) are well known herbaceous medicinal ingredients and have great economic value in Asian countries. However, there are still limited genomic resources available for Aconitum species. In this study, we sequenced the chloroplast (cp) genomes of two Aconitum species, A. coreanum and A. carmichaelii, using the MiSeq platform. The two Aconitum chloroplast genomes were 155,880 and 157,040 bp in length, respectively, and exhibited LSC and SSC regions separated by a pair of inverted repeat regions. Both cp genomes had 38% GC content and contained 131 unique functional genes including 86 protein-coding genes, eight ribosomal RNA genes, and 37 transfer RNA genes. The gene order, content, and orientation of the two Aconitum cp genomes exhibited the general structure of angiosperms, and were similar to those of other Aconitum species. Comparison of the cp genome structure and gene order with that of other Aconitum species revealed general contraction and expansion of the inverted repeat regions and single copy boundary regions. Divergent regions were also identified. In phylogenetic analysis, Aconitum species positon among the Ranunculaceae was determined with other family cp genomes in the Ranunculales. We obtained a barcoding target sequence in a divergent region, ndhC-trnV, and successfully developed a SCAR (sequence characterized amplified region) marker for discrimination of A. coreanum. Our results provide useful genetic information and a specific barcode for discrimination of Aconitum species.