甜玉米种子营养品质主要性状全基因组关联分析

利用玉米56K SNP芯片评估包含100份甜玉米自交系的甜玉米育种资源群体的群体结构,并对种子营养品质性状进行关联定位。结果表明:100份甜玉米自交系可划分为两个亚群,其中,亚群1包括92份种质,亚群2包括8份种质。利用获得均匀覆盖甜玉米基因组的37 297个高质量SNP发现,PIC值集中在0.19、基因多样性变幅集中在0.36~0.38。甜玉米种子中淀粉含量、蛋白质含量、脂肪含量波动较大,其中,淀粉含量变幅在53.91%~73.70%,蛋白质含量变幅在8.96%~18.01%,脂肪含量变幅在5.53%~18.50%。利用GLM-Q模型关联定位到控制甜玉米种子淀粉含量、蛋白质含量、脂肪含量的SNP位点分别是14、15和20,能够解释表型变异的3.45%~51.69%。其中,在-log₁₀P>3.50水平下,位于3号染色体上Affx-115329496处的qSTA-3-1对淀粉含量贡献率最大,约为20.90%;位于1号染色体Affx-91181539处的qPRO-1-1位点和9号染色体上Affx-115333989处的qPRO-9-2与种子蛋白质含量显著关联;而5号染色体Affx-91137282处的qFAT-5-1与种子脂肪含量显著关联。

Genome-wide association study of seed nutritional quality in sweet corn

In this study, a 56K SNP chip was used to evaluate the structure of natural population in 100 sweet corn inbred lines and to locate the seed nutritional quality with association mapping. The results showed that 100 inbred lines were divided into two subgroups, the subgroup 1 contained 92 germplasms and the subgroup 2 contained 8 germplasms. PIC values of 37 297 high-quality SNPs with uniform genome coverage were concentrated at 0.19, and the variation of gene diversity was concentrated between 0.36 and 0.38. The starch content of seed was in 53.91%-73.70%, the protein content was in 8.96%-18.01% and the fat content was in 5.53%-18.50%. There were 14, 15 and 20 SNP molecular markers revealed by GLM-Q model for starch content, protein content and fat content in sweet corn seeds which could explain 3.45%-51.69% of phenotypic variation. At -log₁₀P>3.50 level, the qSTA-3-1 that was on Affx-115329496 of No.3 chromosome could explain 20.90% of starch variation. qPRO-1-1 and qPRO-9-2 were the significant association locus with protein content of sweet corn, which were on the Affx-91181539 of No.1 chromosome and on the Affx-115333989 of No.9 chromosome. qFAT-5-1 on Affx-91137282 of No.5 chromosome was associated with fat content of sweet corn.