基于扬麦38/周麦22RIL群体的株高QTL定位及矮秆多抗小麦材料的鉴定

turalSciencesoftheLixiaheDistrictinJiangsuProvince/KeyLaboratoryof WheatBiologyandGeneticBreedingintheMiddleandLowerYangtze River，Ministry ofAgricultureand Rural Affairs，Yangzhou 225oO7，China；3.College of Agronomy，Henan Agricultural University，Zhengzhou 450002，China；4.Collgeof Agronomy and Biotechnology，Yunnan Agricultural University，Kunming 65oooo，China；5.College ofAgriculture， YangtzeUniversity，Jingzhou ，China）

Abstract： The middle and lower reaches ofthe Yan

gtze River（MLRYR）is the secondlargest wheat-growing regionin China and also an epidemic areafor multiple wheat diseases， such asFusariumhead blight（FHB），powderymildew，andrust.Cultivating newdwarf wheat varieties withresistance tolodging andmultiplediseasesisesentialforsustainablewheatproduction.Yangmai38isaigh-yieldingwheatvarietywithmultipledisease resistances， including high resistance to powdery mildew （carrying Pm2I ）and stripe rust （carrying Yr26 ），and moderate resistance toFHB.However，ithasrelativelytallplantheightandmoderatelodgingresistane.Zhoumai22isadwarfndmultiresistant foundation parent carrying the leaf rust resistance gene _LrI3 and the T1RS·1BL translocation chromosome，and is widelyusedintheHuang-Huaiwheatregion.Inthisstudy，theYangmai38/Zhoumai22recombinantinbredline（RIL）population was genotyped using the wheat 55K single nucleotide polymorphism（SNP）array for quantitative trait loci（QTL）mapping of plant height （PH）.Six QTLfor PH were detected on chromosomes 2B，4B，4D，5A，and 7B.Two major and stable QTL，QPH. yaas- 4B and QPH.yaas- 4D ，were identified across multiple environments，explaining 8.97 % -16.20 % and 23.72 % -28.35% of the phenotypic variance，respectively. These QTL were verified as dwarfing genes Rht1 and Rht2 through physical map comparison and kompetitive alele-specific PCR （KASP）markers. Genetic efect analysis showed that both Rht I and Rht2 significantly reduced plant height，with Rht2 exhibiting a greater dwarfing effect than RhtI The coexistence of RhtI and Rht2 could reduce plant height by 42.98 % -47.16 % . The distribution of resistance genes in the RIL population was also investigated，with homozygous genotype frequencies for Pm2I ， _LrI3 ，Yr26，and T1RS ⋅⋅ 1BL being 40.77% ， 37.41% ，63.07 % ，and 29.98%，respectively，all of which significantly deviated from the expected value （ 50.00% ）.Based on genotyping and agronomic evaluation，five dwarf wheat breeding lines with pyramided Pm2I ， Yr26 ，and _LrI3 were selected for their better comprehensive traits. The results of this study provide theoretical support for breeding wheat varieties with pyramided multi-diseaseresistance inthe MLRYRwheatregion.

Key words： wheat；plant height；resistance genes；molecular markers

近年来，受到气候变暖、降雨量增多、小麦密植和氮肥施用量增加等的影响，长江中下游麦区小麦赤霉病、白粉病、叶锈病和条锈病等发病日趋严重，这些病害还常引发高秆小麦品种倒伏。因此，培育矮秆抗倒伏、综合抗病性强的小麦品种对于长江中下游麦区的安全生产具有重要意义。

小麦白粉病是由禾本科布氏白粉菌小麦专化型（Blumeriagraminisf.sp.tritici）引起的真菌性病害，在长江中下游麦区较为严重发生[2]。来自小麦野生近缘属簇毛麦6VS染色体上的 Pm2I 基因是目前已知抗性最强、抗性谱最广的抗白粉病基因，对几乎所有白粉菌菌株表现出高抗[3]。近年来，随着抗白粉病基因 Pm2aPm4a 的抗性在长江中下游麦区逐步丧失， Pm2I 已成为该麦区最重要的抗白粉病基因源[4]。据统计，2019-2023年间，长江中下游麦区国家级及江苏省级区域试验材料中的高抗白粉病小麦品种中均含有Pm21[5]小麦条锈病、叶锈病分别是由条形柄锈菌小麦专化型（Puccinia striformis f.sp.tritici）小麦叶锈菌（Pucciniatriticina）引起的真菌性病害，该类病菌主要侵染小麦叶片，干扰其光合作用，进而导致小麦减产。小麦-簇毛麦 T6V#2S⋅6AL 易位系92R137的1BL染色体上携带抗条锈病基因 Yr26^[6] ，该基因在西北春麦区、西南麦区被广泛应用。然而，毒性菌株V26的出现和大面积流行导致Yr26的抗性丧失，还造成小麦主栽品种的陆续更替[7-8]。在长江中下游麦区，携带Yr26的小麦品种极为罕见，使得V26从未成为优势菌株[1]。如果进行合理的基因布局，Yr26在长江中下游麦区仍有利用潜力。此外，由于长期以来长江中下游麦区种植者对叶锈病的重视程度不够，同时缺乏育种价值高的抗病亲本资源，并且生产上推广的品种多数为感病品种，导致叶锈病抗性遗传改良进展缓慢。……