Identification of two functional markers associated with drought resistance in maize

Abstract

Drought is recognized as the major abiotic constraint to global food production. Molecular markers have become an important genetic tool for understanding genome dynamics and facilitating molecular breeding of drought resistance. Here, cleaved amplified polymorphic sequence (CAPS) markers dhnC397 and rspC1090 were identified based on the SNP A/G polymorphisms in the drought-resistance genes dhn1 and rsp41. The two alleles of both genes were easily and rapidly discriminated by polyacrylamide gel electrophoresis to reveal single nucleotide polymorphisms (SNPs) as functional markers. By validation of an integrated selection criterion for drought resistance, the average SI (selection index for drought resistance) of lines with superior drought-resistance genotypes was higher than those with opposite, less drought-resistant genotypes, and the SI of heterotic group B was higher than that of heterotic group A for both genes. Integrating the results of CAPS analysis and evaluation of drought resistance indicated that the SNPs in these two genes partly participate in conferring drought resistance in these maize lines of interest. Breeders can thus use the CAPS markers identified here as functional markers for the improvement of drought resistance in these maize lines and possibly others.