Hybrid incompatibilities in interspecific crosses between tetraploid wheat and its wild diploid relative Aegilops umbellulata
Hybrid incompatibilities in interspecific crosses between tetraploid wheat and its wild diploid relative Aegilops umbellulata
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DOI：
10.1007/s11103-017-0677-6
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发表时间：
2017-12-01
影响因子：
5.1
通讯作者：
Takumi, Shigeo
中科院分区：
文献类型：
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作者：
Okada, Moeko;Yoshida, Kentaro;Takumi, Shigeo
四倍体小麦/伞形山羊草杂交种存在杂种异常、生长严重败育和草丛矮化等现象，且与其他小麦合成六倍体杂交体的基因表达变化保持一致。伞形山羊草是一种具有UU基因组的二倍体山羊草品种，已被用作小麦育种的遗传资源。在这里，我们研究了四倍体小麦品种 Langdon (Ldn) 和各种白纹麦之间的生殖障碍。 umbellulata 种质通过进行种间杂交。通过系统的杂交实验，发现了三种类型的杂种不亲和性：杂交制种失败、杂种生长异常和ABU杂种不育。杂种不亲和性广泛分布在整个自然物种范围内，并且在四倍体 Ldn 和 Ae 之间的杂交组合中约占 50%。 umbellulata 种质中，ABU F-1 杂种表现出两种异常生长表型之一：严重生长败育 (SGA) 或草丛矮化。在显示 SGA 的杂交种的冠组织中，茎分生组织维持相关和细胞周期相关基因的表达明显受到抑制，表明茎尖有丝分裂细胞分裂功能障碍。草丛矮化表型可能是通过小麦 APETALA1 样 MADS 盒基因（充当开花启动子）的下调以及控制分蘖数和分枝的 miR156/SPLs 模块在冠部组织中表达的改变来解释的。这些生长异常中的基因表达变化在 Ldn/Ae 之间很好地保守。伞形植物和 Ldn 与小麦 D 基因组祖先 Ae 杂交的种间杂种。节节。
Hybrid abnormalities, severe growth abortion and grass-clump dwarfism, were found in the tetraploid wheat/Aegilops umbellulata hybrids, and the gene expression changes were conserved in the hybrids with those in other wheat synthetic hexaploids.Aegilops umbellulata Zhuk., a diploid goatgrass species with a UU genome, has been utilized as a genetic resource for wheat breeding. Here, we examine the reproductive barriers between tetraploid wheat cultivar Langdon (Ldn) and various Ae. umbellulata accessions by conducting interspecific crossings. Through systematic cross experiments, three types of hybrid incompatibilities were found: seed production failure in crosses, hybrid growth abnormalities and sterility in the ABU hybrids. Hybrid incompatibilities were widely distributed over the entire range of the natural species, and in about 50% of the cross combinations between tetraploid Ldn and Ae. umbellulata accessions, ABU F-1 hybrids showed one of two abnormal growth phenotypes: severe growth abortion (SGA) or grass-clump dwarfism. Expression of the shoot meristem maintenance-related and cell cycle-related genes was markedly repressed in crown tissues of hybrids showing SGA, suggesting dysfunction of mitotic cell division in the shoot apices. The grass-clump dwarf phenotype may be explained by down-regulation of wheat APETALA1-like MADS box genes, which act as flowering promoters, and altered expression in crown tissues of the miR156/SPLs module, which controls tiller number and branching. These gene expression changes in growth abnormalities were well conserved between the Ldn/Ae. umbellulata plants and interspecific hybrids from crosses of Ldn and wheat D-genome progenitor Ae. tauschii.