以课题组前期通过QTL分析挖掘到的玉米萌发期耐低温基因ZmICE6为研究对象，对其进行生物信息学分析，明确其具有bHLH保守结构域，启动子区域包含多种与非生物胁迫相关调控元件。在NCBI数据库中检索玉米基因组bHLH家族成员共71个，对家族基因构建进化树，明确该家族分为8个亚家族。ZmICE6与已知的耐低温基因ZmICE1亲缘关系最近，保守基序预测分析发现，共包含10个motif，其中motif 1、2较为保守，ZmICE6与ZmICE1具有3个相同的保守基序，分别为motif 1、2、5。以123份萌发期耐低温能力不同的玉米自交系为材料，扩增ZmICE6基因CDS区，检测到12个SNP和两个Indel，包含4个非同义突变SNP，其中非同义突变SNP380与萌发期相对根长(RRL)等5个指标极显著相关(P<0.01)，表型贡献率为7.47%～12.62%。针对SNP380位点开发了dCAPs标记DNCAP380，在123份玉米自交系、102份以掖478和齐319为亲本的RIL群体中进行验证，耐低温表型和基因型的符合率分别为76.92%和81.43%。

ZmICE6, a cold tolerance gene during maize germination previously identified via QTL analysis by our research group, was subjected to bioinformatics analysis. The gene contains a conserved bHLH domain, and its promoter region harbors multiple regulatory elements associated with abiotic stress responses. Phylogenetic analysis of 71 maize bHLH members resolved eight sub-clades, with ZmICE6 forming a maximally supported clade alongside the known cold-tolerance regulator ZmICE1; both share conserved motifs 1, 2 and 5. To link sequence variation to phenotype, the complete CDS was amplified from 123 inbreds that span the full spectrum of germination-stage cold vigor. Twelve SNPs and two InDels were recovered, including four non-synonymous changes. Non-synonymous SNP380 showed genome-wide significant associations(P<0.01) with five germination traits—most prominently relative root length—and explained 7.47%-12.62% of phenotypic variance. A dCAPS marker(DNCAP380) designed to track the SNP380 allele achieved 76.92% and 81.43% genotype–phenotype concordance in the original diversity panel and in a 102-line Ye478 × Qi319 RIL population, respectively. DNCAP380 provides breeders with a codominant, cost-effective tool for marker-assisted fixation of cold-resilient ZmICE6 haplotypes.

S513.035.3

东华北春玉米区早熟高产抗逆宜机收新种质创制与应用(2021YFD1201001);黑龙江省自然科学优秀青年基金项目(YQ2022C009)