Association analysis of four storage protein components using microsatellite markers in a japonica rice collection

Wentao Zhang1, Xiuling Zhang1, Jingguo Wang1, Hualong Liu1, Jian Sun1, Hongliang Zheng1, Guangxin Zhao1, Hongwei Zhao1, and Detang Zou1*
Protein content is one of the main nutrition quality traits used to measure nutrition value in rice (Oryza sativa L.) Therefore, improving the protein content is a main target for nutrition quality breeding in rice. Previous studies have mainly focused on the total protein content in brown and polished rice using bi-parental segregating populations. Few researchers have focused on four different protein component traits (glutelin, prolamin, albumin, and globulin) in rice, and little is known regarding association analysis in natural populations. In this study, 329 japonica accessions (Oryza sativa L. subsp. japonica Kato) were collected from worldwide geographic distributions and genotyped using 154 microsatellite markers to detect the association between four protein component traits and relative markers in the tested panel. The Coomassie Brilliant Blue G-250 method was used to measure the phenotype of four protein components. A total of 845 amplified alleles were detected with allele number ranging from 2 to 9. The whole population was divided into three subgroups via software STRUCTURE 2.3.4. The scatterplot showed that the LD (linkage disequilibrium) decay distance was about 30 cM in the whole tested population. A total of 15 simple sequence repeats (SSR) markers were identified by using both the general linear model (GLM) and mixed linear model (MLM). These associated marker loci can provide a higher variety of choices in improving the nutrition quality of rice. In addition, the carrier materials with excellent alleles identified in this study can be used as parental genotypes in rice molecular breeding in the future.
Keywords: Albumin, association analysis, excellent alleles, globulin, glutelin, Oryza sativa subsp. japonica, population structure, prolamin, protein components.
1Northeast Agriculture University, No. 600 Changjiang Street, Harbin 150030, China. *Corresponding author (zoudtneau@126.com).