Fig. 4

ZmRCAβ promoter haplotypes and the average ZmRCAβ expression and grain yield for each haplotype. a Haplotype analysis of the ZmRCAβ promoter regions. The dark gray-shaded cells represent the favorable alleles. *Two lines harboring ZmHap1 and two lines harboring ZmHap2 used for determining ZmRCAβ expression and grain yield were not available in 2016. b, c The average expression of ZmRCAβ and maize grain yield for different haplotypes. Error bars represent the standard error. The number of data points used for calculating the standard error is the product of number of maize lines belonging to each haplotype and biological replicates of each line. Multiple comparison of phenotypic data was performed using Fisher’s protected Least Significant Difference (LSD) test. Different English alphabet means significant difference at P < 0.05