欧亚国际

摘要

异多倍体物种形成是小麦（Triticum spp.）和相关山羊草物种的一个主要进化过程。通过种间杂交产生的合成多倍体人工繁殖了小麦及其亲属的异源多倍体。这些合成多倍体使育种家能够将农业上重要的性状引入硬粒小麦和普通小麦品种中。本研究旨在评价野生小麦（einkorn Triticum monococcum ssp. aegilopoides (Link) Thell.）的遗传和表型多样性，以产生一组包含野生玉米不同Am基因组的合成六倍体系，并揭示其性状特征。我们用覆盖所有染色体的简单序列重复标记检测了43份野生玉米材料的遗传多样性，揭示了两个遗传上不同的谱系，L1和L2。这些谱系之间的遗传差异与其表型差异和栖息地有关。与L2材料相比，L1材料具有开花早、小穗少和小穗大的特点。这些特征差异可能是由于适应了它们不同的栖息地。然后，我们通过以T.turgidum cv.Langdon（AABB基因组）为母本和以野生材料（AmAm基因组）为父本的种间杂交，开发了42个含有AABBAm基因组的合成六倍体。42个AABBAm合成的六倍体中有两个表现出杂种矮化。野生玉米L1和L2材料之间的表型差异，特别是在开花天数和小穗相关性状方面，显著反映了合成六倍体的表型差异。在六倍体背景下，谱系之间的株高和节间差异更为明显。此外，AABBAmAm合成的六倍体小麦具有较长的小穗和籽粒、长芒、高株高、籽粒柔软和开花较晚，这与其他合成的六倍体小麦品系如AABBDD不同。利用野生小麦的各种Am基因组，使AABBAm合成的六聚体具有广泛的表型多样性，为小麦育种提供了有前景的新材料。

Phenotypic effects of Am genomes in nascent synthetic hexaploids derived from interspecific crosses between durum and wild einkorn wheat 

Abstract

Allopolyploid speciation is a major evolutionary process in wheat (Triticum spp.) and the related Aegilops species. The generation of synthetic polyploids by interspecific crosses artificially reproduces the allopolyploidization of wheat and its relatives. These synthetic polyploids allow breeders to introduce agriculturally important traits into durum and common wheat cultivars. This study aimed to evalsuate the genetic and phenotypic diversity in wild einkorn Triticum monococcum ssp. aegilopoides (Link) Thell., to generate a set of synthetic hexaploid lines containing the various Am genomes from wild einkorn, and to reveal their trait characteristics. We examined the genetic diversity of 43 wild einkorn accessions using simple sequence repeat markers covering all the chromosomes and revealed two genetically divergent lineages, L1 and L2. The genetic divergence between these lineages was linked to their phenotypic divergence and their habitats. L1 accessions were characterized by early flowering, fewer spikelets, and large spikelets compared to L2 accessions. These trait differences could have resulted from adaptation to their different habitats. We then developed 42 synthetic hexaploids containing the AABBAmAm genome through interspecific crosses between T. turgidum cv. Langdon (AABB genome) as the female parent and the wild einkorn accessions (AmAm genome) as the male parents. Two of the 42 AABBAmAm synthetic hexaploids exhibited hybrid dwarfness. The phenotypic divergence between L1 and L2 accessions of wild einkorn, especially for days to flowering and spikelet-related traits, significantly reflected phenotypic differences in the synthetic hexaploids. The differences in plant height and internodes between the lineages were more distinct in the hexaploid backgrounds. Furthermore, the AABBAmAm synthetic hexaploids had longer spikelets and grains, long awns, high plant heights, soft grains, and late flowering, which are distinct from other synthetic hexaploid wheat lines such as AABBDD. Utilization of various Am genomes of wild einkorn resulted in wide phenotypic diversity in the AABBAmAm synthetic hexaploids and provides promising new breeding materials for wheat.