Significant associations between single nucleotide polymorphisms and photosynthetic parameters and grain yield in maize

Zhenliang Zhang1, Derong Hao1, Guoqing Chen1, Huhua Lu1, Mingliang Shi1, Guangfei Zhou1, Yuxiang Mao1, Xiaolan Huang1, Junyu Zhao1, and Lin Xue1*
Photosynthesis is the basis of maize (Zea mays L.) grain formation. To further understand the genetic basis of maize photosynthetic parameters and clarify the relationship between maize photosynthetic parameters and grain yield (GY), identifying quantitative trait loci (QTLs) underlying photosynthetic parameters and GY plays an important role in improving maize yield. In this study, a set of 260 maize accessions from different geographic origins were evaluated across three developmental stages in 2 yr to identify QTLs for photosynthetic parameters and grain yield using 2824 single-nucleotide polymorphisms (SNPs) via genome-wide association analysis. The analysis revealed that maize photosynthetic parameters are substantially correlated with GY at different developmental stages. Fourteen SNPs associated with photosynthetic parameters and GY were detected at the threshold of P ≤ 0.001 in 2 yr as well as over years. Moreover, PZE-102116144 and SYN35048 associated with stomatal conductance (gs), and PZE-101152541 associated with photosynthetic rate (PN), were identified at different developmental stages. Four loci were co-associated with two or more traits, such as PZE-101152541 was significantly co-associated with GY and PN (at 25 and 35 d after pollination [DAP]), PZE-102116144 with GY, gs (at 15 and 25 DAP), and PN (at 25 DAP), PZE-109061997 with intercellular CO2 concentration (Ci) (at 25 DAP) and transpiration rate (Tr) (at 25 DAP), PZE-110019199 with gs (at 25 DAP) and GY. Based on functional annotations, two genes were considered as potential candidate genes for the identified SNPs (PZE-101152541 and PZE-109016787). The SNPs and candidate genes identified in this study might provide instrumental information for understanding the genetic mechanism of maize photosynthetic parameters and yield.
Keywords: Photosynthetic parameters, SNPs, yield, Zea mays.
1Jiangsu Yanjiang Institute of Agricultural Sciences, Nantong Key Laboratory for Exploitation of Crop Genetic Resources and Molecular Breeding, Rugao, Nantong, Jiangsu, China. *Corresponding author (417803648@qq.com)