Association Mapping for Grain Quality in a Diverse Sorghum Collection

Abstract

Knowledge of the genetic bases of grain quality traits will complement plant breeding efforts to improve the end-use value of sorghum [Sorghum bicolor (L.) Moench]. Candidate gene association mapping was used on a diverse panel of 300 sorghum accessions to assess marker-trait associations for 10 grain quality traits measured using the single kernel characterization system (SKCS) and near-infrared refl ectance spectroscopy (NIRS). The analysis of the accessions through 1290 genomewide single nucleotide polymorphisms (SNPs) separated the panel into fi ve subpopulations that corresponded to three major sorghum races (durra, kafi r, and caudatum), one intermediate race (guinea-caudatum), and one working group (zerazera-caudatum). These subpopulations differed in kernel hardness, acid detergent fi ber, and total digestible nutrients. After model testing, association analysis between 333 SNPs in candidate genes and/or loci and grain quality traits resulted in eight signifi cant marker-trait associations. A SNP in starch synthase IIa (SSIIa) gene was associated with kernel hardness (KH) with a likelihood ratio-based R 2 (R LR 2 ) value of 0.08, a SNP in starch synthase (SSIIb) gene was associated with starch content with an R LR 2 value of 0.10, and a SNP in loci pSB1120 was associated with starch content with an R LR 2 value of 0.09.

Association mapping of brassinosteroid candidate genes and plant architecture in a diverse panel of Sorghum bicolor

“…This sorghum diversity panel has been previously characterized by different groups using molecular markers; however, the results have not been completely consistent between studies (Casa et al 2008;Sukumaran et al 2012;Brown et al 2011;Morris et al 2013). The population structure of k = 5 reported here is consistent with Sukumaran et al (2012).…”

“…This panel has been successfully used in previous LD mapping studies Sukumaran et al 2012;Morris et al 2013).…”

A High-Throughput, Field-Based Phenotyping Technology for Tall Biomass Crops

“…Maximum geographic and genotypic diversity as well as all sorghum types and races are represented in this panel, which has been used successfully in several association studies (Sukumaran et al, 2012;Morris et al, 2013;Mantilla Perez et al, 2014;Zhao et al, 2016).…”

DNA Markers in Diversity Analysis

“…Though not many studies are available in the use of molecular diversity information directly in the breeding program, it is being extensively used in association mapping of different traits in the recent past. A genome-wide association study (GWAS) of a diverse panel of 300 accessions with 1,290 SNPs was conducted by Sukumaran et al (2012), which resulted in the identification of eight significant marker-trait associations after the association analysis between 333 SNPs in candidate genes and/or loci and grain quality traits. An SNP in starch synthase IIa (SSIIa) gene was associated with kernel hardness (KH), while an SNP in starch synthase (SSIIb) gene and pSB1120 locus was associated with starch content.…”