Variation in sorghum starch synthesis genes associated with differences in starch phenotype

• Published in: Food chemistry 2012-03, Vol.131 (1), p.175-183
• Main Authors: Hill, Helen, Slade Lee, L., Henry, Robert J.
• Format: Article
• Language: English
• Subjects: Associations; Biological and medical sciences; Cereal and baking product industries; Fibre; Food industries; Fundamental and applied biological sciences. Psychology; Protein; RVA; Sorghum; Starch; Starch and starchy product industries
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2011.08.057

► The variation in grain composition and starch properties were evaluated in sorghum. ► SNPs in starch genes were tested for associations with grain quality and RVA traits. ► SNPs in SSIIa distinguish high and low GT sorghum and TKW. ► GBSSI polymorphisms were associated with total starch content. ► SNPs could be developed into allele specific markers to predict sorghum phenotype. The properties of sorghum starch may influence digestibility and nutritional value in animal and human diets and the processing performance of starch in industrial applications. The variation in grain composition and starch physiochemical properties was evaluated. The DNA sequence of three starch synthesis genes was surveyed and an association approach used to investigate the genetic basis of phenotypic differences in sorghum. Single nucleotide polymorphisms (SNPs) in SSIIa distinguish three haplotypes that were associated with significant differences in gelatinisation temperature and thousand-kernel weight. SSIIa haplotype (H1) accessions had a significantly lower mean gelatinisation temperature of 80.5°C compared to 87.6°C and 91.5°C for H2 and H3, respectively. Polymorphisms in SBEIIb were associated with a 12°C difference in gelatinisation temperature and GBSSI polymorphisms with total starch content. The SNPs identified provide a genetic explanation for variation in starch properties in sorghum.