|WU, XUN - Chinese Academy Of Agricultural Sciences|
|LI, YONGXIANG - Chinese Academy Of Agricultural Sciences|
|SHI, YUNSU - Chinese Academy Of Agricultural Sciences|
|SONG, YANCHUN - Chinese Academy Of Agricultural Sciences|
|ZHANG, DENGFENG - Chinese Academy Of Agricultural Sciences|
|LI, CHUNHUI - Chinese Academy Of Agricultural Sciences|
|Buckler, Edward - Ed|
|LI, YU - Chinese Academy Of Agricultural Sciences|
|ZHANG, ZHIWU - Washington State University|
|WANG, TIANYU - Chinese Academy Of Agricultural Sciences|
Submitted to: Plant Biotechnology Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/22/2015
Publication Date: 6/23/2016
Citation: Wu, X., Li, Y., Shi, Y., Song, Y., Zhang, D., Li, C., Buckler IV, E.S., Li, Y., Zhang, Z., Wang, T. 2016. Joint-linkage mapping and GWAS reveal extensive genetic loci that regulate male inflorescence size in maize. Plant Biotechnology Journal. 14(7):1551.
Interpretive Summary: High yielding maize production requires that every kernel is appropriately fertilized by pollen. Making fertilization efficient requires timing, resilience to weather conditions, and appropriate energy balance between pollen and kernel production. This study combined the largest public germplasm resources in the US and China together to identify key genes and natural variation responsible for tassel growth and development. This knowledge will be used to further studies that work to dissect the mechanisms controlling tassel development, and develop mathematical models that can be used to accelerate the breeding of tassels as integrated genomic assisted breeding of maize.
Technical Abstract: Both insufficient and excessive male inflorescence size leads to a reduction in maize yield. Knowledge of the genetic architecture of male inflorescence is essential to achieve the optimum inflorescence size for maize breeding. In this study, we used approximately eight thousand inbreds, including both linkage populations and association populations, to dissect the genetic architecture of male inflorescence. The linkage populations include 25 families developed in the U.S. and 11 families developed in China. Each family contains approximately 200 recombinant inbred lines (RILs). The association populations include approximately 1000 diverse lines from the U.S. and China. All inbreds were genotyped by either sequencing or microarray. Inflorescence size was measured as the tassel primary branch number (TBN) and tassel length (TL). A total of 125 quantitative trait loci (QTLs) were identified (63 for TBN, 62 for TL) through linkage analyses. In addition, 965 quantitative trait nucleotides (QTNs) were identified through genomewide study (GWAS) at a bootstrap posterior probability (BPP) above a 5% threshold. These QTLs/QTNs include 24 known genes that were cloned using mutants, for example Ramosa3 (ra3), Thick tassel dwarf1 (td1), tasselseed2 (ts2), liguleless2 (lg2), ramosa1 (ra1), barren stalk1 (ba1), branch silkless1 (bd1) and tasselseed6 (ts6). The newly identified genes encode a zinc transporter (e.g. GRMZM5G838098 and GRMZM2G047762), the adapt in terminal region protein (e.g. GRMZM5G885628), O-methyl-transferase (e.g. GRMZM2G147491), helix-loop-helix (HLH) DNA-binding proteins (e.g. GRMZM2G414252 and GRMZM2G042895) and an SBP-box protein (e.g. GRMZM2G058588). These results provide extensive genetic information to dissect the genetic architecture of inflorescence size for the improvement of maize yield.