Most Tibetan weedy barleys originated via recombination between Btr1 and Btr2 in domesticated barley  

作　　者：Guangqi Gao Luxi Yan Yu Cai Yu Guo Congcong Jiang Qiang He Sarah Tasnim Zongyun Feng Jun Liu Jing Zhang Takao Komatsuda Martin Mascher Ping Yang 

机构地区：[1]State Key Laboratory of Crop Gene Resources and Breeding/Key Laboratory of Grain Crop Genetic Resources Evaluation and Utilization(MARA)/Institute of Crop Sciences,Chinese Academy of Agricultural Sciences,Beijing 100081,China [2]College of Agronomy,Sichuan Agricultural University,Chengdu 611130,China [3]Leibniz Institute of Plant Genetics and Crop Plant Research,06466 Seeland,Germany [4]Crop Research Institute,Shandong Academy of Agricultural Sciences,Jinan 250100,China

出　　处：《Plant Communications》2024年第5期163-175,共13页植物通讯（英文）

摘　　要：Tibetan weedy barleys reside at the edges of qingke(hulless barley)fields in Tibet(Xizang).The spikes of these weedy barleys contain or lack a brittle rachis,with either two-or six-rowed spikes and either hulled or hulless grains at maturity.Although the brittle rachis trait of Tibetan weedy barleys is similar to that of wild barley(Hordeum vulgare ssp.spontaneum Thell.),these plants share genetic similarity with domesticated barley.The origin of Tibetan weedy barleys continues to be debated.Here,we show that most Tibetan weedy barleys originated from cross-pollinated hybridization of domesticated barleys,followed by hybrid self-pollination and recombination between Non-brittle rachis 1(btr1)and 2(btr2).We discovered the specific genetic ancestry of these weedy barleys in South Asian accessions.Tibetan weedy barleys exhibit lower genetic diversity than wild and Chinese landraces/cultivars and share a close relationship with qingke,genetically differing from typical eastern and western barley populations.We classified Tibetan weedy barleys into two groups,brittle rachis(BR)and non-brittle rachis(NBR);these traits align with the haplotypes of the btr1 and btr2 genes.Whereas wild barleys carry haplotype combinations of Btr1 and Btr2,each showing lower proportions in a population,the recombinant haplotype BTR2H8+BTR1H24 is predominant in the BR group.Haplotype block analysis based on whole-genome sequencing revealed two recombination breakpoints,which are present in 80.6%and 16.8%of BR acces-sions according to marker-assisted analysis.Hybridization events between wild and domesticated barley were rarely detected.Thesefindings support the notion that Tibetan weedy barleys originated via recom-bination between Btr1 and Btr2 in domesticated barley.

关 键 词：Tibetan weedy barley agriocrithon de-domestication out-pollination recombination brittle rachis 

分 类 号：Q94[生物学—植物学]