| 摘要: |
| 为明确玉米穗部发育相关性状的主效QTL位点，利用玉米自交系‘B73’与‘郑58’构建F2群体，采用48K液相杂交捕获探针进行基因型鉴定，结合多个环境下测得的表型数据对玉米穗轴长与穗轴粗进行QTL定位和全基因组预测。结果表明:穗轴长与穗轴粗在基因型、环境、基因型与环境的互作3个变异项均具有显著差异，穗轴长性状与穗轴粗性状的广义遗传力分别是0.71与0.52。穗轴长共检测到8个QTL，表型贡献率为3.54%~12.64%，在3号染色体检测1个新的主效QTL，即qCL3，LOD为8.31，表型贡献率为12.64%。穗轴粗共检测到3个QTL，表型贡献率为7.92%~10.61%，在4号染色体上检测到1个新的主效QTL，即qCD4-1，LOD为5.14，表型贡献率为10.61%。穗轴长与穗轴粗全基因预测的精度分别为0.56和0.39，全基因组预测精度随着训练群体和标记数目的增加而增加，当训练群体大小达到总群体的60%、标记密度达到500个时，预测精度增加幅度变缓。 |
| 关键词: 玉米 穗轴长 穗轴粗 QTL定位 全基因组预测 |
| DOI：10.11841/j.issn.1007-4333.2022.04.04 |
| 投稿时间：2020-04-20 |
| 基金项目:国家自然科学基金(32060484)；国家自然科学基金(U2003304) |
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| QTL mapping and genomic selection of cob length and diameter in maize |
|
LI Zongze,XU Xiaoming,SUN Qiang,YANG Caixia,XU Jiabo,WU Penghao
|
| (College of Agronomy, Xinjiang Agricultural University, Urumqi 830052, China) |
| Abstract: |
| To determine the genetic basis of cob length and cob diameter, an F2 population derived from a cross between maize inbred lines ‘B 73' and ‘Zheng 58' was used for QTL analysis. The population was genotyped by 48K liquid-phase hybridization capture probes and phenotype multi-environment trials. The results showed that: Both cob length and cob diameter displayed significant differences in genotype, environment, and the interaction between genotype and environment. The broad-sense heritability of cob length and cob diameter were 0. 71 and 0. 52, respectively. A total of eight QTLs were identified for cob length. The phenotypic variation explained(PVE)of each QTL ranged from 3. 54% to 12. 64%. A novel major QTL qCL3 was detected on chromosome 3 with a LOD value of 8. 31, and a PVE of 12. 64%. Three QTL were detected for cob diameter, with PVE ranging from 7. 92% to 10. 61%. A major QTL qCD4-1 was identified on chromosome 4 with a LOD value of 5. 14 and a PVE of 10. 61%. The prediction accuracies of genomic selection(GS)for cob length and cob diameter were 0. 56 and 0. 39, respectively. The prediction accuracy was increased with the increase of marker density and training population size, and the increase of GS prediction accuracy slowed down when the number of markers reached 500 and the training population size reached 60% of the total genotypes. |
| Key words: maize cob length cob diameter QTL mapping genomic selection |
