Genetic analysis and QTL mapping of seed coat color in sesame (Sesamum indicum L.)

• Published in: PloS one Vol. 8; no. 5; p. e63898
• Main Authors: Zhang, Haiyang, Miao, Hongmei, Wei, Libin, Li, Chun, Zhao, Ruihong, Wang, Cuiying
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 21-05-2013; Public Library of Science (PLoS)
• Subjects: Agriculture; Agronomy; Algorithms; Amplified fragment length polymorphism; Analysis; Analysis of Variance; Antioxidants; Biology; Chromosome Mapping; Coating effects; Color; Coloration; Crosses, Genetic; Density; Disease resistance; Epistasis; Gene loci; Gene mapping; Genes; Genetic analysis; Genetic aspects; Genetics; Genetics, Population; Genomes; Germplasm; Glycine max; Heritability; Likelihood Functions; Linkage analysis; Mapping; Marker-assisted selection; Melilotus albus; Models, Genetic; Phenotype; Pigmentation - genetics; Population; Population genetics; Populations; Quantitative genetics; Quantitative trait loci; Quantitative Trait Loci - genetics; Quantitative Trait, Heritable; Seed coats; Seeds; Seeds - genetics; Sesamum - genetics; Sesamum indicum; Studies
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0063898

Seed coat color is an important agronomic trait in sesame, as it is associated with seed biochemical properties, antioxidant content and activity and even disease resistance of sesame. Here, using a high-density linkage map, we analyzed genetic segregation and quantitative trait loci (QTL) for sesame seed coat color in six generations (P1, P2, F1, BC1, BC2 and F2). Results showed that two major genes with additive-dominant-epistatic effects and polygenes with additive-dominant-epistatic effects were responsible for controlling the seed coat color trait. Average heritability of the major genes in the BC1, BC2 and F2 populations was 89.30%, 24.00%, and 91.11% respectively, while the heritability of polygenes was low in the BC1 (5.43%), in BC2 (0.00%) and in F2 (0.89%) populations. A high-density map was constructed using 724 polymorphic markers. 653 SSR, AFLP and RSAMPL loci were anchored in 14 linkage groups (LG) spanning a total of 1,216.00 cM. The average length of each LG was 86.86 cM and the marker density was 1.86 cM per marker interval. Four QTLs for seed coat color, QTL1-1, QTL11-1, QTL11-2 and QTL13-1, whose heritability ranged from 59.33%-69.89%, were detected in F3 populations using CIM and MCIM methods. Alleles at all QTLs from the black-seeded parent tended to increase the seed coat color. Results from QTLs mapping and classical genetic analysis among the P1, P2, F1, BC1, BC2 and F2 populations were comparatively consistent. This first QTL analysis and high-density genetic linkage map for sesame provided a good foundation for further research on sesame genetics and molecular marker-assisted selection (MAS).