Nitrate transporters (NRTs) are regulators of nitrate assimilation and transport. The genome sequences of TaNRT2L12-A, -B and -D were cloned from wheat (Triticum aestivum L.), and polymorphisms were analyzed by sequencing. TaNRT2L12-D in a germplasm population was highly conserved. However, 38 single nucleotide polymorphisms (SNPs) in TaNRT2L12-A coding region and 11 SNPs in TaNRT2L12-B coding region were detected. Two derived cleaved amplified polymorphic sequences (dCAPS) markers A-CSNP1 and A-CSNP2 were developed for TaNRT2L12-A based on SNP-351 and SNP-729, and three haplotypes were identified in the germplasm population. B-CSNP1 and B-CSNP2 were developed for TaNRT2L12-B based on SNP-237 and SNP-1227, and three haplotypes were detected in the germplasm population. Association analyses between the markers and agronomic traits in 30 environments and phenotypic comparisons revealed that A-CSNP2-A is a superior allele of shorter plant height (PH), length of penultimate internode (LPI) and peduncle length (PL), B-CSNP2-G is a superior allele of higher grain number per spike (GNS). Hap-6B-1 containing both superior alleles B-CSNP1-C and B-CSNP2-A is a superior haplotype of 1 000-grain weight (TGW). Expression analysis showed that TaNRT2L12-B is mainly expressed in the root base and regulated by nitrate. Therefore, TaNRT2L12 may be involved in nitrate transport and signaling to regulate TGW in wheat. The superior alleles and dCAPS markers of TaNRT2L12-A/B are beneficial to genetic improvement and germplasm enhancement with molecular markers-assisted selection.

硝酸盐转运蛋白（NRTs）是硝酸盐吸收和转运的调节剂。从小麦（Triticum aestivum L.）中克隆了TaNRT2L12-A，-B和-D的基因组序列，并通过测序分析了其多态性。种质种群中的TaNRT2L12-D高度保守。但是，检测到TaNRT2L12-A编码区中的38个单核苷酸多态性（SNP）和TaNRT2L12-B编码区中的11个SNP 。为TaNRT2L12-A开发了两个衍生的切割的扩增多态序列（dCAPS）标记A-CSNP1和A-CSNP2基于SNP-351和SNP-729，在种质群体中鉴定出三种单倍型。基于SNP-237和SNP-1227为TaNRT2L12-B开发了B-CSNP1和B-CSNP2 ，并在种质种群中检测到三种单倍型。在30种环境中的标记和农艺性状之间的关联分析以及表型比较显示，A-CSNP2-A是较短的植株高度（PH），倒数第二节间长度（LPI）和花序长度（PL），B-CSNP2的优良等位基因-G是每个穗粒数（GNS）更高的优良等位基因。同时包含优良等位基因B-CSNP1-C和B-CSNP2-A的Hap-6B-1是具有1000粒重（TGW）的优良单倍型。表达分析表明TaNRT2L12-B主要在根基中表达，并受硝酸盐调节。因此，TaNRT2L12可能参与硝酸盐转运和信号传导，从而调节小麦的TGW。TaNRT2L12-A / B的优良等位基因和dCAPS标记通过分子标记辅助选择有利于遗传改良和种质增强。