Starch is the most important component in endosperm of sorghum grain.  Usually, two types of starch are present: amylose (AM) and amylopectin (AP).  The levels of AM and AP contents play a significant role in the appearance, structure, and quality of sorghum grains and in marketing applications.  In the present study, a panel of 634 sorghum (Sorghum bicolor (L.) Moench) accessions were evaluated for starch, AM, and AP contents of grain, which included a mini core collection of 242 accessions from the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in India, and 252 landraces and 140 cultivars from China.  The average starch content was 67.64% and the average AM and AP contents were 20.19 and 79.81%, respectively.  We developed a total of 260 000 high-confidence single nucleotide polymorphism (SNP) markers in the panel of 634 accessions of S. bicolor using specific locus amplified fragment sequencing (SLAF-seq).  We performed genome-wide association studies (GWAS) of starch, AM, and AM/AP of grain and SNP markers based on a mixed linear model (MLM).  In total, 70 significant association signals were detected for starch, AM, and AM/AP ratio of grain with P<4.452×10^–7, of which 10 SNPs were identified with significant starch, 51 SNPs were associated with AM, and nine SNPs were associated with the AM/AP ratio.  The Gene Ontology (GO) analysis identified 12 candidate genes at five QTLs associated with starch metabolism within the 200-kb intervals, located on chromosomes 1, 5, 6, and 9.  Of these genes, Sobic.006G036500.1 encodes peptidyl-prolyl cis-trans-isomerase CYP38 responsible for hexose monophosphate shunt (HMS) and Sobic.009G071800 encodes 6-phospho-fructokinase (PFK), which is involved in the embden-meyerhof pathway (EMP).  Kompetitive allele specific PCR (KASP) markers were developed to validate the GWAS results.  The C allele is correlated with a high starch content, while the T allele is linked with a low level of starch content, and provides reliable haplotypes for MAS in sorghum quality improvement.

DNA barcodes have been proposed as a shortcut to provide species identification and as a way to accelerate the discovery of new species. A number of candidate gene regions have been suggested as possible barcodes for animals and plants, but for the identification of recently diverged species and/or varieties with only a few genetic differences it has been reported to be problematic in some cases. This study selected widely cultivated cruciferous vegetables as the primary samples, after failure of discrimination of each species using current DNA barcodes, we performed the fluorescent amplified fragment length polymorphism (F-AFLP) and successfully discriminated each species, subspecies, variety and their cultivar in 74 samples. Then the non-qualitative results obtained from F-AFLP were transformed into two-dimensional barcodes image file of each cultivar via the PDF417 software. This method was also successfully applied to the discrimination of 17 Chinese indigenous pig breeds. The barcode we constructed which greatly reduces the information storage space is genotypes-specific, and can be conveniently decoded into the original data and thereby be conveniently shared and referred to. We believe that it is possible to construct a new data sharing molecular barcode system that could discriminate the subspecies, varieties, cultivars and even individuals with close genetic relationships.