小麦新品种川麦104的遗传构成分析

【目的】解析突破性高产小麦新品种川麦104的遗传构成，探讨双亲川麦42和川农16对其高产特性的贡献。【方法】利用已构建的遗传连锁图谱上的176个SSR和683个DArT标记对川麦104及其亲本进行分析，了解川麦104的遗传构成；根据已定位到的产量性状QTL，分析来源于双亲的染色体区段对川麦104产量相关性状的贡献。【结果】在川麦104的双亲具有差异的859个多态位点中（22个位点缺失），有522个位点上的等位基因来源于川麦42，315个位点上的等位基因来源于川农16；川麦104更多地继承了川麦42的遗传成分（60.8%）；川麦104中来源于双亲的遗传位点在A、B和D基因组分布不同，来源于川麦42的等位位点在A、B和D基因组所占比例分别为55.00%、60.20%和67.27%；川麦104中来源于双亲的等位位点在21条染色体上的分布也不同，来源于川麦42的等位位点主要分布于3A、5A、7A、1B、5B、7B、3D、4D、5D和7D染色体上，来源于川农16的等位位点主要分布于4A、3B、4B、6B、1D、2D和6D染色体上。川麦104来源于双亲的染色体区段（遗传距离大于5 cM）共68个，总长度为3 089.6 cM；来源于川麦42和川农16的染色体区段分别为36和32个，来源于川麦42的染色体区段主要分布在3D、5D、7A、7B和7D染色体上，来源于川农16的染色体区段主要分布在3B、4B和6D染色体上；在A和D基因组川麦104来源于川麦42的染色体区段比川农16的多，B基因组中来源于川农16的染色体区段比川麦42的多。在1B、1D、2B、4A、4D、5A、5B、5D和7A染色体上，9个来源于川麦42的染色体区段以及5个来源于川农16的染色体区段富集了与产量性状相关的QTL，其中，在1BS和4A染色体上来源于川麦42的染色体区段携带增加穗粒数的QTL等位位点；在1D、2B和4A染色体上来源于川农16的染色体区段携带增加单位面积穗数的QTL等位位点；5B染色体上来源于川麦42的染色体区段和4A、4D染色体上来源于川农16的染色体区段均携带增加千粒重的QTL等位位点，这些QTL的聚合对川麦104的产量三因素有增效作用。【结论】小麦新品种川麦104的高穗粒数特性来源于川麦42，多穗数特性来源于川农16，其千粒重特性双亲均有贡献，表明双亲的正效产量性状QTL重组是川麦104的高产遗传基础。

Dissection of Genetic Components in the New High-Yielding Wheat Cultivar Chuanmai 104

【Objective】The objective of the study is to dissect the genetic components of the new high-yielding wheat cultivar Chuanmai 104 developed by crossing wheat cultivars Chuanmai 42 with Chuannong 16 and detect the parental contribution to it. 【Method】Chuanmai 104 and its parents were genotyped using all the involved markers covering the whole genome to dissect the genetic components of Chuanmai 104. The parental contributions to the yield-related function of the genomic regions of Chuanmai 104 from each parent were also analyzed according to the authors’ previous-identified QTLs.【Result】Among the 859 polymorphic genetic loci (22 were missing in Chuanmai 104), the alleles at 522 loci in Chuanmai 104 were from the parent Chuanmai 42, while the alleles at the other 315 loci were from the other parent Chuannong 16. Therefore, Chuanmai 104 inherited more alleles from the parent Chuanmai 42 (60.8%). Parental contributions to Chuanmai 104 differed among A, B and D genomes and chromosomes. The frequencies of the alleles from Chuanmai 42 at the investigated loci of A, B and D genomes were 55.00%, 60.20% and 67.27%, respectively. These loci from Chuanmai 42 were broadly distributed on chromosomes 3A, 5A, 7A, 1B, 5B, 7B, 3D, 4D, 5D and 7D, and the other loci from Chuannong 16 were located on chromosomes 4A, 3B, 4B, 6B, 1D, 2D and 6D. A total of 68 genomic regions with the genetic distance larger than 5 cM were detected in Chuanmai 104, which were inherited from its parents and the total genetic length was 3,089.6 cM all over the whole map. Among these genomic regions, the parents Chuanmai 42 and Chuannong 16 contributed about 36 and 32 genomic regions to Chuanmai 104, respectively. The genomic regions inherited from Chuanmai 42 were distributed on chromosomes 3D, 5D, 7A, 7B and 7D, and the other regions from Chuannong 16 were located on chromosomes 3B, 4B and 6D. Chuanmai 104 inherited more genomic regions from Chuanmai 42 in A and D genomes and the genomic regions inherited from Chuannong 16 were more than those from Chuanmai 42 in B genome. In these detected genomic regions on chromosomes 1B, 1D, 2B, 4A, 4D, 5A, 5B, 5D and 7A, about nine genomic regions with Chuanmai 42-type haplotype and five genomic regions with Chuannong 16-type haplotype were significantly associated with yield-related traits by QTL mapping using the Chuanmai 42×Chuannong 16 RILs, respectively. In the yield-related genomic regions, the QTL alleles increasing the spike number per square meter on 1D, 2B and 4A chromosomes were provided by the parent Chuannong 16, while QTL alleles associated with more grain number per spike on 1BS chromosome arm and 4A chromosome were from the other parent Chuanmai 42. Moreover, Chuanmai 104 inherited the QTL alleles with higher thousand-kernel weight from both parents on 5B, 4A and 4D chromosomes, respectively. The pyramiding of these additive QTL alleles from each parent enhanced yield-related traits, which led directly to the character of high yield potential of Chuanmai 104. 【Conclusion】The parental contributions of Chuanmai 42 and Chuannong 16 to their offspring Chuanmai 104 in a whole genome scale was confirmed. Chuanmai 104 inherited the desirable properties of higher grain number per spike from Chuanmai 42, spike number per square meter from Chuannong 16, and thousand-kernel weight combined from both parents by phenotypic and QTL analysis. These characteristics are the genetic basis contributed to the high yield potential of Chuanmai 104.