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 (g
s), and
PZE-101152541 associated with photosynthetic rate (P
N),
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 P
N
(at 25 and 35 d after pollination [DAP]), PZE-102116144
with GY, g
s (at 15 and 25 DAP), and P
N (at 25 DAP),
PZE-109061997 with intercellular CO
2 concentration
(C
i) (at 25 DAP) and transpiration rate (T
r) (at 25 DAP),
PZE-110019199 with g
s (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.
