文献类型： 外文期刊

作者： Li, Zhiyong ¹ ; Li, Chunhui ¹ ; Zhang, Ruyang ¹ ; Duan, Minxiao ¹ ; Tian, Hongli ¹ ; Yi, Hongmei ¹ ; Xu, Liwen ¹ ; Wang, Fengge ¹ ; Shi, Zi ¹ ; Wang, Xiaqing ¹ ; Wang, Jidong ¹ ; Su, Aiguo ¹ ; Wang, Shuai ¹ ; Sun, Xuan ¹ ; Zhao, Yanxin ¹ ; Wang, Shuaishuai ¹ ; Zhang, Yunxia ¹ ; Wang, Yuandong ¹ ; Song, Wei ¹ ; Zhao, Jiuran ¹ ;

作者机构： 1.Beijing Acad Agr & Forestry Sci, Maize Res Inst, Beijing Key Lab Maize DNA Fingerprinting & Mol Bre, Beijing, Peoples R China

关键词： X lines; heterotic group; ICRs; SSWs; yield-related genes

期刊名称：FRONTIERS IN PLANT SCIENCE （ 影响因子：5.6； 五年影响因子：6.8 ）

ISSN： 1664-462X

年卷期： 2023 年 14 卷

页码：

收录情况： SCI

摘要： Genome-wide analyses of maize populations have clarified the genetic basis of crop domestication and improvement. However, limited information is available on how breeding improvement reshaped the genome in the process of the formation of heterotic groups. In this study, we identified a new heterotic group (X group) based on an examination of 512 Chinese maize inbred lines. The X group was clearly distinct from the other non-H&L groups, implying that X x HIL is a new heterotic pattern. We selected the core inbred lines for an analysis of yield-related traits. Almost all yield-related traits were better in the X lines than those in the parental lines, indicating that the primary genetic improvement in the X group during breeding was yield-related traits. We generated whole-genome sequences of these lines with an average coverage of 17.35x to explore genome changes further. We analyzed the identity-by-descent (IBD) segments transferred from the two parents to the X lines and identified 29 and 28 IBD conserved regions (ICRs) from the parents PH4CV and PH6WC, respectively, accounting for 28.8% and 12.8% of the genome. We also identified 103, 89, and 131 selective sweeps (SSWs) using methods that involved the pi, Tajima's D, and CLR values, respectively. Notably, 96.13% of the ICRs co-localized with SSWs, indicating that SSW signals concentrated in ICRs. We identified 171 annotated genes associated with yield-related traits in maize both in ICRs and SSWs. To identify the genetic factors associated with yield improvement, we conducted QTL mapping for 240 lines from a DH population (PH4CV x PH6WC, which are the parents of X1132X) for ten key yield-related traits and identified a total of 55 QTLs. Furthermore, we detected three QTL clusters both in ICRs and SSWs. Based on the genetic evidence, we finally identified three key genes contributing to yield improvement in breeding the X group. These findings reveal key loci and genes targeted during pedigree breeding and provide new insights for future genomic breeding.