Genome structure and apomixis in Phoenicaulis(Brassicaceae;Boechereae)  

作　　者：Terezie Mandakova Kaylynn Ashby Bo J.Price Michael D.Windham John G.Carman Martin A.Lysak 

机构地区：[1]CEITEC,Masaryk University,Brno,CZ-62500,Czech Republic [2]Plants,Soils,and Climate Department,Utah State University,Logan,UT 84322-4820,USA [3]Department of Biology,Duke University,Durham,NC 27708,USA

出　　处：《Journal of Systematics and Evolution》2021年第1期83-92,共10页植物分类学报（英文版）

基　　金：This article is dedicated to Dr.Ihsan A.Al-Shehbaz(Missouri Botanic Garden)on the occasion of his 80th birthday.This work was supported by Czech Ministry of Education,Youth and Sports within the program INTER-EXCELLENCE(project No.LTAUSA17002),by the CEITEC 2020 project(grant No.LQ1601 to MAL),the Utah Agricultural Experiment Station project awards,Utah State University,Logan to JC,and the U.S.National Science Foundation(award DEB-0816560 to MDW).

摘　　要：Apomixis in crucifer(Brassicaceae)species is rare,reported in just four genera(Boechera,Draba,Erysimum,and Parry a),and one intergeneric hybrid(Raphanobrassica).It is well studied only in Boechera,where it is widespread among 100+recognized species.However,its occurrence in related genera of the tribe Boechereae has not been documented previously.Here we analyzed genome evolution,mode of reproduction,and fertility of the monospecific Boechereae genus Phoenicaulis(P.cheiranthoides),endemic to the northwestern United States.We discovered that the species encompasses diploid(2n=2x=14),triploid(2n=3x=21),and tetraploid(2n=4x=28)populations.Comparative chromosome paining analyses revealed that the three karyotypes are essentially structurally identical,differing only in the presence of a largely heterochromatic chromosome(Het)in the triploid and tetraploid cytotypes.The genome structure of Phoenicaulis appeared identical to that of Boechera species previously analyzed,sugges廿ng genomic stasis despite the morphological and molecular divergence of the two genera.This genome colinearity extended to the presenee and structure of the Het chromosomes,which are closely associated with apomictic reproduction in Boechera.Interestingly,all three cytotypes of Phoenicaulis proved to be apomictic,regardless of the presenee or absence of a Het chromosome,and sexual populations have yet to be identified.

关 键 词：APOMIXIS APOSPORY AUTOPOLYPLOIDY BOECHERA Brassicaceae karyotype evolution 

分 类 号：Q94[生物学—植物学]