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作者	单位
陈玉翠，胡鑫，赵燕昊，彭星木，丁明全，戎均康	（1.浙江农林大学现代农学院，浙江省农产品品质改良技术研究重点实验室，浙江临安311300；2.桐庐县农业技术推广中心，浙江桐庐311500；3.桐庐县瑶琳镇人民政府，浙江桐庐311500)

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中文摘要:

小麦株高与植株倒伏密切相关，影响小麦产量。为挖掘小麦株高QTL位点和候选基因，从遗传和分子水平上解释株高分子机理，本研究将野生二粒小麦染色体臂置换系CASL7AS为母本，课题组自选株系浙农林12（简称ZNL12）为父本，杂交F₁经过花培得到178个DH群体。通过4年2个种植点株高数据，利用55K SNP芯片构建高密度遗传图谱，对小麦株高性状进行QTL分析。该遗传连锁图谱包含3 655个SNP标记,长度为4 738.45 cM，标记间平均遗传距离为1.30 cM，覆盖了小麦21条染色体。其中,A、B、D染色体组分别含有标记1 466、1 492和697个。QTL分析共检测出53个QTL位点，分布于1A、3A、5A、7A、1B、3B、4B、5B、7B、2D、4D、6D和7D染色体上，可解释2.80%~38.50%表型变异。其中,稳定主效 QTL有2个，分别为QPh.zafu.4B-1和QPh.zafu.4D-1，其贡献率分别为25.18%~38.50%和20.67%。经细胞生物学分析，基因型为（0,2）矮秆植株胚芽鞘的表皮细胞长度显著短于基因型为（2,0）的高秆植株，基因型为（0,0）、（2,2）中间型的植株胚芽鞘表皮细胞长度无显著差异，由此推测小麦株高的变异由细胞长度因素决定。QPh.zafu.4B-1候选基因Rht-B1b基因编码区矮秆株系，第904核苷酸处发生碱基“C-T”的突变，形成终止密码子(CAG-TAG)；而QPh.zafu.4D-1候选基因Rht-D1b基因编码区矮秆株系，第781核苷酸处碱基突变“G-T”，编码氨基酸中缬氨酸变为天冬氨酸。结果为小麦株高候选基因的筛选和QTL定位提供了优异的遗传位点和候选基因，未来可用于小麦抗倒伏相关的分子标记辅助育种。

英文摘要:

Wheat yield is impacted by plant lodging, which is closely related to wheat plant height. In order to explore QTLs and candidate genes of wheat plant height, and to explain the mechanisms determining plant height from the genetic and molecular levels, this study used a Triticum dicoccoides chromosome arm substitution line CASL7AS as the female parent and a locally bred line Zhenonglin 12 (referred to as ZNL12) as the male parent to obtain F₁. 178 DH lines were obtained through anther culture. A high-density genetic map was constructed utilizing the 55K SNP array based on the plant height data collected at two locations over the period of four years in order to perform QTL analysis for wheat plant height traits. The genetic linkage map contains 3 655 SNP markers with a length of 4 738.45 cM, consisting of 1 466, 1 492, and 697 markers in A, B and D sub-genomes,respectively. The average genetic distance between markers is 1.30 cM, covering 21 chromosomes of wheat. A total of 53 QTLs were obtained by QTL analysis, explaining 2.80% to 38.50% of the phenotypic variance, and dispersing on the chromosomes 1A, 3A, 5A, 7A, 1B, 3B, 4B, 5B, 7B, 2D, 4D, 6D, and 7D. Among them, there were two stable main effect QTLs, namely QPh.zafu.4B-1 and QPh.zafu.4D-1, which explained 25.18%-38.50% and 20.67% of the phenotypic variation, respectively. Cytobiological studies revealed that the epidermal cell length of coleoptiles from dwarf plants with genotype (0,2) was significantly shorter than that of tall plants with genotype (2,0), while there was no discernible difference between intermediate genotype (0,0) and (2,2). It was concluded that the cell length was responsible for the difference in wheat plant height. The results showed that the candidate gene of QPh.zafu.4B-1 was Rht-B1b, and a “C-T” mutation occurred at the 904th locus, causing a termination codon (CAG-TAG). For dwarf plants in the coding region of Rht-D1b, a candidate gene of QPh.zafu.4D-1, a “G-T” mutation occurred at the 781st locus, changing the valine to aspartic acid. This work has successfully identified and found the genetic loci for screening potential genes of wheat plant height trait, which can be employed in future molecular marker-assisted breeding for wheat lodging resistance.

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