Joshi Pabitra, Dhillon Guriqbal Singh, Gao Yaotian, Kaur Amandeep, Wheeler Justin, Chen Xianming, Krause William, Krause Margaret R, Chen Jianli
Department of Plant Sciences, University of Idaho Aberdeen, R and E Center, Aberdeen, ID, 83210, USA.
Department of Plant Pathology, USDA-ARS, Wheat Health, Genetics, and Quality Research Unit and, Washington State University, Pullman, WA, 99164-6430, USA.
Theor Appl Genet. 2025 Jan 7;138(1):18. doi: 10.1007/s00122-024-04795-7.
Two dwarf bunt resistance QTLs were mapped to chromosome 6D, and KASP markers associated with the loci were developed and validated in a panel of regionally adapted winter wheats. UI Silver is an invaluable adapted resistant cultivar possessing the two identified QTL potentially associated with genes Bt9 and Bt10 and will be useful in future cultivar development to improve dwarf bunt resistance. Dwarf bunt, caused by Tilletia controversa, is a fungal disease of wheat that can cause complete loss of grain yield and quality during epidemics. Traditional breeding for dwarf bunt resistance requires many years of field screening under stringent conditions with disease assessment possible only near or after plant maturity. Molecular marker-assisted selection (MAS) offers a more efficient alternative. This study identified quantitative trait loci (QTL) and associated molecular markers for dwarf bunt resistance in wheat. A doubled haploid (DH) mapping population of 135 lines, derived from bunt-resistant cultivar 'UI Silver' and susceptible line 'Shaan89150', was evaluated in field nursery in Logan, Utah in 2017, 2018, and 2023. The population was genotyped using Illumina 90 K SNP iSelect marker platform. Using inclusive composite interval mapping (ICIM), the major QTL Qdb.ssdhui-6DL was consistently identified on chromosome arm 6DL across all environments, explaining phenotypic variations ranging from 15.29% to 35.40%. Another QTL, Qdb.ssdhui-6DS, was detected on chromosome arm 6DS, explaining approximately 11% of the phenotypic variation. These two QTLs exhibit additive-by-additive effects for increased resistance within the DH population. Kompetitive allele-specific PCR (KASP) markers were developed within QTL intervals and used in a validation panel of regionally adapted winter wheat lines to confirm the association between the two QTL and dwarf bunt resistance. Thus, 'UI Silver' and additional resistant cultivars with these two QTLs are valuable parental lines for improving dwarf bunt resistance through marker-assisted selection. These genetic resources are essential for understanding gene function via map-based gene cloning.
两个抗矮腥黑穗病的数量性状基因座（QTL）被定位到6D染色体上，并开发了与这些基因座相关的竞争性等位基因特异性PCR（KASP）标记，并在一组区域适应性冬小麦中进行了验证。UI Silver是一个非常宝贵的适应性抗病品种，拥有两个已鉴定的可能与Bt9和Bt10基因相关的QTL，将有助于未来品种改良以提高对矮腥黑穗病的抗性。矮腥黑穗病由网腥黑粉菌引起，是小麦的一种真菌病害，在病害流行期间可导致谷物产量和品质完全丧失。传统的抗矮腥黑穗病育种需要在严格条件下进行多年的田间筛选，且只有在植株接近成熟或成熟后才能进行病害评估。分子标记辅助选择（MAS）提供了一种更有效的替代方法。本研究鉴定了小麦抗矮腥黑穗病的数量性状基因座（QTL）及相关分子标记。2017年、2018年和2023年，在犹他州洛根的田间苗圃中对一个由抗腥黑穗病品种‘UI Silver’和感病品系‘陕89150’构建的包含135个株系的双单倍体（DH）作图群体进行了评估。利用Illumina 90K SNP iSelect标记平台对该群体进行基因分型。采用完备复合区间作图法（ICIM），在所有环境下均在6DL染色体臂上一致鉴定出主效QTL Qdb.ssdhui-6DL，解释的表型变异范围为15.29%至35.40%。在6DS染色体臂上检测到另一个QTL Qdb.ssdhui-6DS，解释了约11%的表型变异。这两个QTL在DH群体中对增强抗性表现出加性×加性效应。在QTL区间内开发了KASP标记，并用于区域适应性冬小麦品系的验证群体中，以确认这两个QTL与矮腥黑穗病抗性之间的关联。因此，‘UI Silver’和具有这两个QTL的其他抗病品种是通过标记辅助选择提高矮腥黑穗病抗性的宝贵亲本系。这些遗传资源对于通过基于图谱的基因克隆来理解基因功能至关重要。
