Nucleotide polymorphisms of the maize ZmCWINV3 gene and their association with ear-related traits

Cell-wall invertases (CWINVs), responsible for the hydrolysis of sucrose into glucose and fructose, play important roles in plant development. Maize (Zea mays L.) ear-related traits were suggested to be important components of kernel yield. However, the association and nucleotide polymorphisms of maize CWINV genes with ear-related traits remain largely unclear. Herein, the maize ZmCWINV3 gene was re-sequenced in 301 inbred lines, 71 landraces and 31 teosintes to mine excellent variations associated with ear-related traits. A total of 594 variants, including 498 single nucleotide polymorphisms (SNPs) and 96 insertions and deletions (InDels), were identified in maize ZmCWINV3 locus. Five polymorphism sites in ZmCWINV3 were found to be significantly associated with six ear-related traits. Among them, a non-synonymous mutation SNP3694 was found to be significantly associated with ear weight (EW), ear grain weight (EGW), ear length (EL) and kernel length (KL). Further evidence revealed that the excellent allele T of SNP3694 was not exist in teosintes, while its frequencies raised to 9.86% and 69.44% in landraces and inbred lines, respectively. These observations suggested that the excellent allelic variations in ZmCWINV3 might possess potential application values in the genetic improvement of ear-related traits in maize.