【摘要】 长期以来，我国黄淮及北部地区的普通小麦(Triticum aestivum)种植遭受干旱胁迫严重。小麦根系构型(root system architecture, RSA)相关性状与营养元素和水分的吸收和转运息息相关，对于小麦高产和稳产至关重要。因此，挖掘小麦RSA相关性状遗传位点，并开发可用分子标记对于小麦高产和稳产育种具有重要意义。本研究测定了’豆麦’/’石4185’重组自交系(recombinant inbred lines, RIL)群体中的根尖平均直径(average root diameter, ARD)、根体积(total root volume, TRV)和根干重(root dry weight, RDW) 3个重要RSA相关性状。通过小麦90K SNP芯片对RIL群体和亲本进行了基因分型。利用全基因组连锁分析分别鉴定到2个ARD (QARD.caas-2B和QARD.caas-6A)、2个RDW (QRDW.caas-2A和QRDW.caas-5B)和1个TRV (QTRV.caas-3A)相关遗传位点，分别解释6.25%～7.59%、7.21%～10.30%和7.59%的表型变异。其中，QARD.caas-6A、QRDW.caas-2A和QTRV.caas-3A是新发现位点。QRDW.caas-5B的优异等位基因来自于’豆麦’，而QARD.caas-2B、QARD.caas-6A、QRDW.caas-2A和QTRV.caas-3A的有利等位基因来自’石4185’。根据小麦参考基因组序列信息，在目标区段鉴定出5个候选基因，分别与植物激素调节、耐逆反应和信号转导相关。开发并验证了1个竞争性等位基因特异性PCR (kompetitive allele specific PCR, KASP)标记Kasp＿2A＿RDW (QRDW.caas-2A)，该标记与小麦根系干重显著有关，并对115个小麦高代品系进行了基因分型。本研究为优化小麦根系构型，提升小麦耐逆性，选育高产稳产品种提供了新的基因和可用KASP标记。更多还原

【Abstract】 For a long time, the production of common wheat(Triticum aestivum) in the Huang-Huai and northern regions of China has been severely threatened by drought stress. Traits related to the root system architecture(RSA) of wheat are closely associated with the absorption and translocation of nutrients and water, which are crucial for high-yield and stable-yield of wheat. Thus, identifying loci for RSA traits and developing available markers are crucial for high and stable yield wheat breeding. In this study, RSA-related traits, including average root diameter(ARD), total root volume(TRV), and root dry weight(RDW), were evaluated in the ’Doumai’/’Shi4185’ recombinant inbred line(RIL) population under hydroponics. In addition,both the RILs and parents were genotyped using the wheat 90K SNP array. Using whole genome linkage analysis, 2 loci related to ARD(QARD.caas-2B and QARD.caas-6A), 2 loci related to RDW(QRDW.caas-2A and QRDW.caas-5B), and 1 locus related to TRV(QTRV.caas-3A) were identified and each explaining 6.25%～7.59%, 7.21%～10.30% and 7.59% of the phenotypic variances, respectively. Among these, QARD. caas-6A,QRDW.caas-2A and QTRV.caas-3A were novel loci. The favorable allele of QRDW.caas-5B was contributed by the ’Doumai’, whereas the favorable allele of QARD. caas-6A, QRDW. caas-2A and QTRV. caas-3A were originated from ’Shi4185’. Five candidate genes related to plant hormone regulation, stress tolerance, and signal transduction were identified, respectively. Additionally, one competitive allele-specific PCR(KASP)marker, Kasp＿2A＿RDW(QRDW.caas-2A) was developed and validated in 115 wheat accessions, this marker was significantly associated with wheat RDW. The study provides new genes and available KASP markers for optimizing wheat root RSA, improving wheat resistance to abiotic stress and high and stable yield breeding.更多还原