Journal of Integrative Agriculture ›› 2021, Vol. 20 ›› Issue (5): 1180-1192.DOI: 10.1016/S2095-3119(20)63192-6

所属专题: 麦类遗传育种合辑Triticeae Crops Genetics · Breeding · Germplasm Resources

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  • 收稿日期:2019-11-13 出版日期:2021-05-01 发布日期:2021-04-12

QTL mapping of seedling biomass and root traits under different nitrogen conditions in bread wheat (Triticum aestivum L.)

YANG Meng-jiao1, 2, WANG Cai-rong2, 3, Muhammad Adeel HASSAN2, WU Yu-ying2, XIA Xian-chun2, SHI Shu-bing1, XIAO Yong-gui2, HE Zhong-hu2, 4 
 
  

  1. 1 College of Agriculture, Xinjiang Agricultural University, Urumqi 830052, P.R.China
    2 National Wheat Improvement Centre, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100081, P.R.China
    3 Institute of Agricultural Science of Yili Prefecture, Yining 835000, P.R.China
    4 International Maize and Wheat Improvement Centre (CIMMYT) China Office, c/o CAAS, Beijing 100081, P.R.China
  • Received:2019-11-13 Online:2021-05-01 Published:2021-04-12
  • Contact: Correspondence XIAO Yong-gui, E-mail: xiaoyonggui@caas.cn; HE Zhong-hu, E-mail: hezhonghu02@caas.cn
  • Supported by:
    This work was funded by the National Key R&D Program of China (2016YFD0101804-6), the National Natural Science Foundation of China (31671691) and the International Science & Technology Cooperation Program of China (2016YFE0108600).

摘要:

苗期根系的氮素吸收与利用效率是决定植株生长发育及产量收益的关键因素,研究氮肥调控下小麦苗期根系生物量及其相关形态学的遗传调控对培育高产稳产小麦品种具有重要意义。本研究利用扬麦16/中麦895构建的DH群体,分别在硝酸钙浓度为0 mmol L−1(空白对照)、0.05 mmol L−1(低氮)、2.0 mmol L−1(高氮)3个梯度下进行液体培养,对4个根系生物量相关性状和5个根系结构性状进行基因定位,及连锁标记遗传转化研究。结果表明,不同氮肥处理与基因型间存在显著差异,根系生物量相关性状与结构性状间呈显著正相关,范围在0.20-0.98。基于全基因组660K SNP高密度遗传图谱,共定位到51个调控根系性状QTL,主要分布在12个根系性状调控基因富集区。并发掘出12个受氮肥调控影响的根系性状新基因,包括1AL染色体上携带受0氮调控的1个基因、1DS携带受高氮调控2个、4BL携带受高氮和低氮调控5个、7DS和7DL分别携带受低氮调控的3个和1个基因。4DS染色体上与Rht-D1 基因临近区域携带有控制根系性状且遗传表现稳定的基因QRRS.caas-4DS,解释表型变异为13.1%。12个根系性状基因富集区包括28个QTL位点,其中6BL和7BL染色体上的两个富集区C10和C11较为重要,主要控制根系干重、根表面积和幼苗干重等性状,连锁标记AX-109558906-6B和AX-95025477-7B已转化成育种可用的KASP标记。本研究发掘的QTL位点、QTL富集区及开发的KASP标记将有助于小麦育种工作中的苗期根系性状遗传改良。


Abstract:

Plant nitrogen assimilation and use efficiency in the seedling’s root system are beneficial for adult plants in field condition for yield enhancement.  Identification of the genetic basis between root traits and N uptake plays a crucial role in wheat breeding.  In the present study, 198 doubled haploid lines from the cross of Yangmai 16/Zhongmai 895 were used to identify quantitative trait loci (QTLs) underpinning four seedling biomass traits and five root system architecture (RSA) related traits.  The plants were grown under hydroponic conditions with control, low and high N treatments (Ca(NO3)2·4H2O at 0, 0.05 and 2.0 mmol L−1, respectively).  Significant variations among the treatments and genotypes, and positive correlations between seedling biomass and RSA traits (r=0.20 to 0.98) were observed.  Inclusive composite interval mapping based on a high-density map from the Wheat 660K single nucleotide polymorphisms (SNP) array identified 51 QTLs from the three N treatments.  Twelve new QTLs detected on chromosomes 1AL (1) in the control, 1DS (2) in high N treatment, 4BL (5) in low and high N treatments, and 7DS (3) and 7DL (1) in low N treatments, are first reported in influencing the root and biomass related traits for N uptake.  The most stable QTLs (RRS.caas-4DS) on chromosome 4DS, which were related to ratio of root to shoot dry weight trait, was in close proximity of the Rht-D1 gene, and it showed high phenotypic effects, explaining 13.1% of the phenotypic variance.  Twenty-eight QTLs were clustered in 12 genetic regions.  SNP markers tightly linked to two important QTLs clusters C10 and C11 on chromosomes 6BL and 7BL were converted to kompetitive allele-specific PCR (KASP) assays that underpin important traits in root development, including root dry weight, root surface area and shoot dry weight.  These QTLs, clusters and KASP assays can greatly improve the efficiency of selection for root traits in wheat breeding programmes.
 

Key words: KASP marker ,  QTL analysis ,  root traits ,  SNP array ,  Triticum aestivum