中国农业科学 ›› 2021, Vol. 54 ›› Issue (21): 4487-4499.doi: 10.3864/j.issn.0578-1752.2021.21.001

• 作物遗传育种·种质资源·分子遗传学 • 上一篇    下一篇

小麦苗期生物量及氮效率相关性状的全基因组关联分析

张鹏霞1(),周秀文1,梁雪2,郭营1,赵岩1,李斯深1,孔凡美1,*()   

  1. 1山东农业大学/作物生物学国家重点实验室/土肥资源高效利用国家工程实验室,山东泰安 271018
    2山东省曹县土壤肥料工作站,山东曹县 274400
  • 收稿日期:2021-02-07 接受日期:2021-04-14 出版日期:2021-11-01 发布日期:2021-11-09
  • 通讯作者: 孔凡美
  • 作者简介:联系方式:张鹏霞,E-mail: zhangpengxia0824@163.com
  • 基金资助:
    山东省重大科技创新工程项目(2018YFJH0602)

Genome-Wide Association Analysis for Yield and Nitrogen Efficiency Related Traits of Wheat at Seedling Stage

ZHANG PengXia1(),ZHOU XiuWen1,LIANG Xue2,GUO Ying1,ZHAO Yan1,LI SiShen1,KONG FanMei1,*()   

  1. 1Shandong Agricultural University/State Key Laboratory of Crop Biology/National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Tai’an 271018, Shandong;
    2Caoxian Soil Fertilizer Workstation of Shandong Province, Caoxian 274400, Shandong
  • Received:2021-02-07 Accepted:2021-04-14 Online:2021-11-01 Published:2021-11-09
  • Contact: FanMei KONG

摘要:

【目的】探究不同氮素供应环境下与小麦苗期生物量及氮效率相关性状显著关联的SNP位点,预测相关候选基因,为小麦氮效率的基因克隆及其在育种中的应用提供参考。【方法】以134个小麦品种(系)组成的群体为供试群体,设置低氮、正常氮和高氮3个处理,各处理重复4次,并在2年(2013和2014年)进行了2次完全重复的营养液培养试验。试验对小麦苗期生物量及氮效率相关的14个性状进行了表型鉴定,采用MLM+K+Q混合线性模型,利用90K SNP芯片对小麦生物量及氮效率相关性状进行全基因组关联分析(genome-wide association study,GWAS),获得显著关联的SNP位点。【结果】与正常氮处理相比,低氮处理条件下,根系、地上部及植株氮含量和氮积累量均显著下降,而根生物量和根、植株氮效率均显著增加,高氮处理下,几乎所有鉴定性状均显著增加;14个性状的广义遗传力均在40%以上,其中,植株总干重的遗传力最高(95.73%)。利用9 329个SNP标记进行关联分析,共检测到838个SNP标记位点与供试材料的14个性状存在显著关联(P≤0.001),分布在21条染色体上。有435个(51.91%)SNP标记位点仅在一个关联分析环境中被检测到;有403个位点至少在2个处理环境(包含均值环境)中被检测到与同一性状显著关联(稳定关联标记)。其中8个SNP标记位点至少在3个环境中被检测到。在4个环境下(包括均值环境)均检测到的稳定关联位点有2个:Kukri_c65481_121和tplb0025f09_1052,分别与植株总氮利用效率(total nitrogen use efficiency of plant,TNUE)和根系总氮利用效率(root nitrogen use efficiency,RNUE)显著关联;同时与至少6个性状(生物量及养分效率相关性状)显著关联的SNP标记位点共5个,分别位于1A、1B(3)和2A染色体上;根据小麦基因组注释及LD衰减水平,在同时定位了6个性状的5个SNP位点和2个多环境(4个环境)稳定关联的SNP位点的214 kb的基因组区域中共筛选候选基因84个,根据已知克隆氮效率基因的编码蛋白类型、候选基因功能注释信息及利用植物比较基因组学资源库蛋白序列同源比对分析,筛选到3个候选基因与生物量及氮效率相关。【结论】不同氮素处理显著影响小麦苗期生物量、氮效率相关性状及其相关QTL的表达,大多数SNP位点仅在1个氮素检测环境中被检测到,但也存在环境稳定性较强的位点。生物量及氮效率相关性状之间存在显著相关关系,并在一定程度上受到相同的QTL/基因控制。

关键词: 小麦, 全基因组关联分析, 生物量, 氮效率

Abstract:

【Objective】 To identify and locate the molecular markers which were stable and significantly correlated to the traits of biomass and N efficiency under different N nutrition levels will help to provide reference for cloning and characterization of the related genes.【Method】A group of 134 wheat varieties (or lines) were used in a two-years (2013 and 2014) hydroponic experiments, in which three treatments applying normal level N, low level N and high level N were set up. Fourteen traits related to biomass and N efficiency were measured, as the respective average values of each treatment in one year and two years. Genome-wide association analysis using 90K SNP molecular markers was carried out for the tested traits by MLM+K+Q mixed linear model. 【Result】 Compared with normal nitrogen treatments, roots, shoots, and plant nitrogen content and nitrogen accumulation were significantly reduced in low nitrogen treatments, while root biomass and root and plant nitrogen efficiency were significantly increased. In high nitrogen treatments, almost all traits are significantly increased. The heritability of all the tested traits were above 40%. According to genome-wide association analysis on the 9 329 SNPs, a total of 838 molecular marker sites were identified associating with 14 traits significantly (P≤0.001). These markers located on 21 chromosomes, among which 435 (51.91%) molecular marker sites were detected in only one environment, 403 and 8 environment stable sites were identified in at least two or three environments, two environmental stable SNP marker sites were identified in at least four environments. The two stable markers (Kukri_c65481_121 and tplb0025f09_1052) were significantly related to total nitrogen use efficiency of plant (TNUE) and root nitrogen use efficiency (RNUE), respectively. Five multi-trait co-location SNP marker sites which simultaneously associated with at least six traits were located on chromosomes 1A, 1B(2), and 2A(2). Furtherly, candidate gene prediction was conducted in the 214 kb genomic region of 5 SNP sites co-located with 6 traits (biomass and N efficiency traits) and 2 SNP sites associated with multiple environments (4 environments). According to the genome annotation and LD attenuation level, a total of 84 candidate genes were determined. Gene function annotations of these genes were performed using the coding protein types of known cloned nitrogen efficiency genes, candidate gene function annotation information and the use of plant comparative genomics resource library protein sequence homology analysis, 3 candidate genes were initially determined. 【Conclusion】 Different N treatments significantly affected the phenotypic traits of biomass, N efficiency and the expression of related QTLs at seedling stage of wheat. Most SNPs were detected in only one N environment, but there were some locations with relatively strong environmental stability. There was a significant correlation between biomass and N efficiency related traits, and they might be partly controlled by the same QTL/gene. The functions of related candidate genes related to N efficiency and biomass of wheat selected in this paper needed to be further verified.

Key words: wheat, GWAS, biomass, nitrogen efficiency