Abstract
Kernel length, kernel width, and kernel thickness are important traits affecting grain yield and product quality. Here, the genetic architecture of the three kernel size traits was dissected in an association panel of 309 maize inbred lines using four statistical methods. Forty-two significant single nucleotide polymorphisms (SNPs; p < 1.72E-05) and 70 genes for the three traits were identified under five environments. One and eight SNPs were co-detected in two environments and by at least two methods, respectively, and they explained 5.87–9.59% of the phenotypic variation. Comparing the transcriptomes of two inbred lines with contrasting seed size, three and eight genes identified in the association panel showed significantly differential expression between the two genotypes at 15 and 39 days after pollination, respectively. Ten and 17 genes identified by a genome-wide association study were significantly differentially expressed between the two development stages in the two genotypes. Combining environment−/method-stable SNPs and differential expression analysis, ribosomal protein L7, jasmonate-regulated gene 21, serine/threonine-protein kinase RUNKEL, AP2-EREBP-transcription factor 16, and Zm00001d035222 (cell wall protein IFF6-like) were important candidate genes for maize kernel size and development.
Highlights
Maize is one of the most important crops and is widely used as staple food, animal feed, and raw materials
364 TFs showed more than two-fold expression between the two genotypes, of which GRAS-transcription factor 3 (GRAS3), E2F-DP-transcription factor 214 (E2F14), E2F8, NAC100, NAC-transcription factor 61 (NAC61), MYBR110, MYBR58, bHLH-transcription factor 38 (bHLH38), WRKY-transcription factor 15 (WRKY15), and AGL8-like protein (AGL8L) showed high differential expression in AJ525 relative to A340 (Supplementary Table S5). Apart from these TFs, we found 86 genes encoding ribosomal proteins, 33 genes encoding pentatricopeptide repeat-containing protein (PPR), and 59 genes associated with ubiquitin-conjugating enzyme, and ubiquitinprotein ligase showed over two-fold difference between AJ525 and A350 at DAP15 (Supplementary Figure S7)
Elucidation of the variation of kernel size will facilitate to reveal the regulatory mechanisms of maize kernel development
Summary
Maize is one of the most important crops and is widely used as staple food, animal feed, and raw materials. Kernel size traits, including kernel length (KL), kernel width (KW), and kernel thickness (KT), largely affect yield component kernel weight and product quality. Large kernels have a favorable seed vigor and, promote yield. It is important to elucidate the genetic architecture of kernel size. Liu et al (2014) identified 6, 16, and 18 QTLs for KL, KW, and KT, respectively, accounting for 0.84–20.51% of phenotypic variation in an F2:3 population. Liu et al (2017) identified 729 QTLs for KL, KW, KT, and kernel weight in 10 RIL populations using three statistical models In intermated B73 × Mo17 Syn DH population, Liu et al (2020a) found 50 QTLs for KL, KW, and KT, of which 18 QTLs were detected in at least two environments. Liu et al (2017) identified 729 QTLs for KL, KW, KT, and kernel weight in 10 RIL populations using three statistical models
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
