Using a high density bin map to analyze quantitative trait locis of germination ability of maize at low temperatures.

Low temperatures in the spring often lead to a decline in the emergence rate and uniformity of maize, which can affect yield in northern regions. This study used 365 recombinant inbred lines (RILs), which arose from crossing Qi319 and Ye478, to identify low-temperature resistance during the germination stage by measuring eight low-temperature-related traits. The quantitative trait locis (QTLs) were mapped using software by combining phenotypic data, and the genotyping by sequencing (GBS) method to produce a high-density genetic linkage map. Twenty QTLs were detected during QTL mapping, of which seven QTLs simultaneously detected a consistent 197.10-202.30 Mb segment on chromosome 1. The primary segment was named , with a phenotypic variation of 5.18-25.96% and a physical distance of 5.2 Mb. This combines the phenotype and genotype with the identification of seven chromosome segment substitution lines (CSSLs), which were derived from Ye478*Qi319 and related to . The physical distance of was reduced to approximately 1.9 Mb. The consistent meta-QTL was located at 619.06 cM on chromosome 1, had a genetic distance of 7.27 cM, and overlapped with . This was identified by combining the results of previous QTL studies assessing maize tolerance to low temperatures at the germination stage. An assessment of the results of the RIL population, CSSLs, and found the consistent QTL to be . It was identified in bin1.06-1.07 at a confidence interval of between 200,400,148 and 201,775,619 bp. In this interval, qRT-PCR found that relative expression of the candidate genes and were both up-regulated in low-temperature tolerant lines and down-regulated in sensitive lines ( < 0.01).