Two pathways of 2n gamete formation and differences in the frequencies of 2n gametes between wild species and interspecific hybrids
Two pathways of 2n gamete formation and differences in the frequencies of 2n gametes between wild species and interspecific hybrids
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DOI：
10.1007/s00299-022-02915-5
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发表时间：
2022-08-19
影响因子：
6.2
通讯作者：
Miyoshi，Kazumitsu
中科院分区：
文献类型：
--
作者：
Kondo，Haruka;Deguchi，Ayumi;Miyoshi，Kazumitsu
关键信息表皮细胞以高频率产生2n配子。本文首次报道了形成2n配子、减数分裂失败和减数分裂前染色体加倍的多种途径。虽然诱导2n配子的最常见途径之一是通过减数分裂缺陷，但一小部分孤立的物种在减数分裂前阶段从四倍体花粉母细胞产生2n配子。因此，确定2n配子形成的机制对于改进育种计划和理解植物进化至关重要。我们研究了孢子，以揭示解释2n配子在Epidendrum属野生种和种间杂种中形成和频率的途径。我们调查了不同类型的孢子与不同的频率，大小，和生存能力的野生种和杂交种的属Epidendrum。在野生种中观察到大的四分体估计的减数分裂前染色体加倍。表皮植物的独特之处在于它通过两条途径形成2n花粉，即减数分裂缺陷和减数分裂前染色体加倍。这两条2n花粉形成途径可能会影响到具有不同杂合度和遗传背景的表皮松属植物多倍体的高多样性产生。因此，这些发现可能会影响表皮植物通过2n花粉进行多倍体育种，有助于我们理解兰科植物通过未减数2n配子形成的进化和物种形成。
Key messageEpidendrum produces 2ngametes with high frequency. This paper is the first to report on multiple pathways for forming 2ngametes, meiotic defeats, and pre-meiotic chromosome doubling.AbstractUnreduced 2nreproductive cells are predominantly involved in pathways that lead to polyploid plants. Although one of the most common pathways for inducing 2ngametes is through meiotic defects, a small set of isolated species alternatively generates 2ngametes from tetraploid pollen mother cells in the pre-meiotic phase. Hence, determining the mechanisms underlying 2ngamete formation is critical to improving breeding programmes and understanding plant evolution. We investigated sporads to reveal the pathway(s) accounting for the formation and frequencies of 2ngametes in wild species and interspecific hybrids in the genusEpidendrum. We investigated different types of sporads with varying frequencies, sizes, and viability in the wild species and hybrids of the genusEpidendrum. Large tetrad-estimated pre-meiotic chromosome doubling was observed in wild species. TheEpidendrumis unique in that it forms 2npollens via two pathways, namely, meiotic defects and pre-meiotic chromosome doubling. These two pathways of 2npollen formation could influence the high diversity generation of polyploidy with different degrees of heterozygosity and genetic backgrounds in the genusEpidendrum. Therefore, these findings are proposed to influence polyploid breeding ofEpidendrumvia 2npollen, helping us understand evolution and speciation via unreduced 2ngamete formation in Orchidaceae.