The occurrence,inheritance,and segregation of complex genomic structural variation in synthetic Brassica napus  

作　　者：Dandan Hu Jin Lu Wenwen Li Yinghui Yang Junxiong Xu Han Qin Hao Wang Yan Niu Huaiqi Zhang Qingqing Liu Xiangxiang He Annaliese S.Mason JChris Pires Zhiyong Xiong Jun Zou 

机构地区：[1]National Key Laboratory of Crop Genetic Improvement,College of Plant Science and Technology,Huazhong Agricultural University,Wuhan 430070,Hubei,China [2]College of Agronomy,Henan Agricultural University,Zhengzhou 450002,Henan,China [3]Key Laboratory of Herbage and Endemic Crop Biotechnology,Inner Mongolia University,Hohhot 010070,Inner Mongolia,China [4]Plant Breeding Department,University of Bonn,Bonn 53115,Germany [5]Department of Soil and Crop Sciences,Colorado State University,Fort Collins,CO 80523,USA

出　　处：《The Crop Journal》2024年第2期515-528,共14页作物学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(NSFC,31970564,32000397,32171982);the Fundamental Research Funds for the Central Universities(2662023PY004)。

摘　　要："Synthetic"allopolyploids recreated by interspecific hybridization play an important role in providing novel genomic variation for crop improvement.Such synthetic allopolyploids often undergo rapid genomic structural variation(SV).However,how such SV arises,is inherited and fixed,and how it affects important traits,has rarely been comprehensively and quantitively studied in advanced generation synthetic lines.A better understanding of these processes will aid breeders in knowing how to best utilize synthetic allopolyploids in breeding programs.Here,we analyzed three genetic mapping populations(735 DH lines)derived from crosses between advanced synthetic and conventional Brassica napus(rapeseed)lines,using whole-genome sequencing to determine genome composition.We observed high tolerance of large structural variants,particularly toward the telomeres,and preferential selection for balanced homoeologous exchanges(duplication/deletion events between the A and C genomes resulting in retention of gene/chromosome dosage between homoeologous chromosome pairs),including stable events involving whole chromosomes("pseudoeuploidy").Given the experimental design(all three populations shared a common parent),we were able to observe that parental SV was regularly inherited,showed genetic hitchhiking effects on segregation,and was one of the major factors inducing adjacent novel and larger SV.Surprisingly,novel SV occurred at low frequencies with no significant impacts on observed fertility and yield-related traits in the advanced generation synthetic lines.However,incorporating genome-wide SV in linkage mapping explained significantly more genetic variance for traits.Our results provide a framework for detecting and understanding the occurrence and inheritance of genomic SV in breeding programs,and support the use of synthetic parents as an important source of novel trait variation.

关 键 词：ALLOPOLYPLOID Large Genome structural variation Linkage mapping Synthetic polyploids Inheritance and segregation 

分 类 号：S565.4[农业科学—作物学]