Shi Huawei, Chen Ming, Gao Lifeng, Wang Yanxia, Bai Yanming, Yan Huishu, Xu Chengjie, Zhou Yongbin, Xu Zhaoshi, Chen Jun, Tang Wensi, Wang Shuguang, Shi Yugang, Wu Yuxiang, Sun Daizhen, Jia Jizeng, Ma Youzhi
Key Laboratory of Sustainable Dryland Agriculture, College of Agriculture, Shanxi Agricultural University, Jinzhong, 030801, China.
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS), National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, 100081, China.
Theor Appl Genet. 2022 Dec;135(12):4289-4302. doi: 10.1007/s00122-022-04218-5. Epub 2022 Sep 22.
GWAS identified 347 QTLs associated with eight traits related to nitrogen use efficiency in a 389-count wheat panel. Four novel candidate transcription factor genes were verified using qRT-PCR. Nitrogen is an essential nutrient for plants that determines crop yield. Improving nitrogen use efficiency (NUE) should considerably increase wheat yield and reduce the use of nitrogen fertilisers. However, knowledge on the genetic basis of NUE during wheat maturity is limited. In this study, a diversity panel incorporating 389 wheat accessions was phenotyped for eight NUE-related agronomic traits across five different environments. A total of 347 quantitative trait loci (QTLs) for low nitrogen tolerance indices (ratio of agronomic characters under low and high nitrogen conditions) were identified through a genome-wide association study utilising 397,384 single nucleotide polymorphisms (SNPs) within the MLM (Q + K) model, including 11 stable QTLs. Furthermore, 69 candidate genes were predicted for low nitrogen tolerance indices of best linear unbiased predictions values of the eight studied agronomic traits, and four novel candidate transcription factors (TraesCS5A02G237500 for qFsnR5A.2, TraesCS5B02G384500 and TraesCS5B02G384600 for qSLR5B.1, and TraesCS3B02G068800 for qTKWR3B.1) showed differing expression patterns in contrasting low-nitrogen-tolerant wheat genotypes. Moreover, the number of favourable marker alleles calculated using NUE that were significantly related to SNP in accessions decreased over the decades, indicating a decline in the NUE of the 389 wheat varieties. These findings denote promising NUE markers that could be useful in breeding high-NUE wheat varieties, and the candidate genes could further detail the NUE-related regulation network in wheat.
全基因组关联研究（GWAS）在一个包含389份小麦材料的群体中，鉴定出了347个与氮素利用效率相关的8个性状的数量性状基因座（QTL）。利用qRT-PCR验证了4个新的候选转录因子基因。氮是植物必需的营养元素，决定着作物产量。提高氮素利用效率（NUE）应能显著提高小麦产量并减少氮肥使用。然而，关于小麦成熟期氮素利用效率遗传基础的认识有限。在本研究中，一个包含389份小麦材料的多样性群体在5种不同环境下对8个与氮素利用效率相关的农艺性状进行了表型分析。通过在混合线性模型（MLM，Q + K）中利用397,384个单核苷酸多态性（SNP）进行全基因组关联研究，共鉴定出347个低氮耐受指数（低氮和高氮条件下农艺性状的比值）的数量性状基因座，其中包括了11个稳定的QTL。此外，针对8个研究农艺性状的最佳线性无偏预测值的低氮耐受指数预测了69个候选基因，4个新的候选转录因子（qFsnR5A.2的TraesCS5A02G237500、qSLR5B.1的TraesCS5B02G384500和TraesCS5B02G384600，以及qTKWR3B.1的TraesCS3B02G068800）在低氮耐受不同的小麦基因型中表现出不同的表达模式。此外，利用与氮素利用效率显著相关的SNP计算出的有利标记等位基因数量在几十年间有所减少，表明这389个小麦品种的氮素利用效率有所下降。这些发现表明了有前景的氮素利用效率标记，可用于培育高氮素利用效率的小麦品种，且候选基因可进一步详细阐述小麦中与氮素利用效率相关的调控网络。
