Genome-wide association study of resistant starch (RS) phenotypes in a barley variety collection.

Abstract

Barley is primarily grown for feed and malt, but in some regions of the world it is also considered to be a staple food. Some barley types such as high-amylose barley have also gained importance as health-promoting foods. Starch that is not readily digested in the upper mammalian gastrointestinal system, or resistant starch (RS), is considered to be valuable because it prevents some diet-related diseases such as colon cancer. RS was quantified in a diverse collection of 209 spring barley varieties released in Europe during the past 100 years. The RS content varied from <1% to >15% in the collection, with 13 varieties having high RS content (>11%) and 15 varieties below 1%. Combined with genome-wide association scanning (GWAS), SNP markers and candidate genes controlling the RS content in grains were identified. This identified 40 SNP markers with a LOD score above 2, located on chromosomes 2H, 3H, 5H, and 6H, respectively. Among these SNPs, 10 genes with a known role in starch biosynthesis were associated on the basis of synteny conservation to the rice genome. The β-glucan content was quantified in 61 varieties selected to represent extreme as well as medium RS values. The β-glucan amount in the 15 varieties with RS <1% ranged from 1.7 to 3.2%, ranged from 1.76 to 2.54% in the 13 varieties with RS >11%, and ranged from 1.95 to 2.82% for those with 1%< RS < 11%. No statistically significant correlation between RS content and β-glucan content was found. This association analysis of commercial varieties revealed a large variation in RS content and identified a number of SNP markers that can be explored for selection and further dissection of the pathway and control of RS phenotype.

• Authors: Xiaoli Shu, Gunter Backes, Søren K Rasmussen
• Journal: Journal of agricultural and food chemistry (J Agric Food Chem) Vol. 60 Issue 41 Pg. 10302-11 (Oct 17 2012) ISSN: 1520-5118 [Electronic] United States
• PMID: 22998083 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Genetic Markers
• beta-Glucans
• Starch
• Amylose

Topics

• Amylose (analysis)
• Chromosome Mapping
• Digestion
• Genetic Markers
• Genome-Wide Association Study
• Hordeum (chemistry, genetics)
• Linkage Disequilibrium
• Lod Score
• Phenotype
• Polymorphism, Single Nucleotide (genetics)
• Starch (genetics, metabolism)
• beta-Glucans (analysis)