Studies on applying SNP markers to breeding drought-tolerant maize hybrids

Vietnam is one of the countries most affected by climate change, with a number of serious droughts occurring in the 2015-2017 period. With around 80% of the cultivated area under rainfed condition, drought is considered the biggest challenge for maize production in Vietnam [2]. Therefore, the research and selection of drought-tolerant maize varieties that have high grain yield and the ability to adapt to climate change are of great interest to maize breeders. However, drought tolerance is a low-heritability trait that is regulated by multiple genes; it requires substantial money and time to accomplish these daunting research and selection tasks. Fortunately, genomic selection (GS) by means of mapping quantitative trait loci (QTL) relating to drought tolerance using molecular markers is an efficient and time-saving tool in plant breeding. It results in the achievement of greater breeding value through selection at the early stages of the improvement cycle [3]. Currently, using single nucleotide polymorphisms (SNPs) is becoming more common in plant breeding through marker-assisted selection and is replacing simple sequence repeats (SSRs) for crops, such as maize, whose genomes have been completely sequenced [4].