Genomic footprints of wheat evolution in China reflected by a Wheat660K SNP array  

作　　者：Zhiwei Wang Chenyang Hao Jing Zhao Chang Li Chengzhi Jiao Wei Xi Jian Hou Tian Li Hongxia Liu Xueyong Zhang 

机构地区：[1]Key Laboratory of Crop Gene Resources and Germplasm Enhancement,Ministry of Agriculture and Rural Affairs/The National Key Facility for Crop Gene Resources and Genetic Improvement/Institute of Crop Sciences,Chinese Academy of Agricultural Sciences,Beijing 100081,China [2]Novogene Bioinformatics Institute,Beijing 100083,China

出　　处：《The Crop Journal》2021年第1期29-41,共13页作物学报（英文版）

基　　金：supported by the National Key Research and Development Program of China(2016YFD0100302);the CAAS Program(Y2017PT39);Jiangsu Collaborative Innovation Center for Modern Crop Production。

摘　　要：Common wheat(Triticum aestiuum L.)is one of the most important crops because it provides about 20%of the total calories for humans.T.aestiuum is an excellent modern species for studying concerted evolution of sub-genomes in polyploid species,because of its large chromosome size and three well-known genome donors.Establishment of common wheat genome reference sequence and development of high-density SNP chips provide an excellent foundation to answer questions of wheat evolution and breeding at the genomic level.By genotyping more than 600 accessions of common wheat and their diploid and tetraploid ancestors using a Wheat660 K SNP array,we found dramatic genome changes due to tetraploidization and hexaploidization,in contrast to weaker influences of domestication and breeding on them.Further,since common wheat was introduced in China in 1500 BCE,Chinese landraces formed two subgroups(T.aestiuum-L1 and T.aestiuum-L2)with considerably diverse geographic distributions and agronomic traits.T.aestiuum-L2,mainly distributed in central and east China is found to have more but smaller oval grains with early maturity characteristics.We found that variation and selection in intergenic regions of the A and B sub-genomes dominated this differentiation,in which chromosomes 7 A and 3 B took the leading roles due to the existence of putative genes related to defense responses and environmental adaption in the highly differentiated regions.Large haplotype blocks were detected on 3 B(232.6-398.3 Mb)and 7 A(211.7-272.9 Mb)in the landraces,forming two distinct haplotypes,respectively.We discovered that artificial crosses in breeding promoted recombination in the whole genome,however,this recombination and differentiation was highly asymmetric among the three sub-genomes in homoeologous regions.In addition,we found that the wide use of European and northern American cultivars in breeding at early era,led dramatic changes in Chinese wheat genome,whereas,the recent breeding functioned to optimize it.This study will provide the insight

关 键 词：WHEAT POLYPLOIDIZATION DIFFERENTIATION Asymmetric recombination Haplotype block 

分 类 号：S512.1[农业科学—作物学]