2n egg formation in Populus × euramericana (Dode) Guinier
2n egg formation in Populus × euramericana (Dode) Guinier
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DOI：
10.1007/s11295-012-0510-y
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发表时间：
2012-05
影响因子：
2.4
通讯作者：
X. Xi;Dan Li;Wenting Xu;Liqin Guo;Jin-feng Zhang;B. Li
中科院分区：
文献类型：
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作者：
X. Xi;Dan Li;Wenting Xu;Liqin Guo;Jin-feng Zhang;B. Li
以欧美杨（Populus ×euramericana（Dode）Guinier）为母本，意大利黑杨（Populus nigravar.italica（Moench.）Koehne通过在授粉前后的某些发育阶段用秋水仙素处理雌性花芽进行胚胎拯救，并通过流式细胞仪分析进行鉴定。共21个微卫星引物被用来推断形成杂种的配子的倍性和潜在的减数分裂机制。结果表明，2n卵来源于白杨，在三倍体中贡献了额外的单倍体基因组。此外，根据这些三倍体的标记基因型，在母本树中产生第一次分裂恢复（FDR）2n卵。大孢子发生的细胞学分析表明，母本减数分裂是不同步的。这一细胞学证据表明，2n卵是由秋水仙素处理后的FDR产生的，因为大孢子母细胞（MMCs）的一部分在授粉后阶段的第一次分裂中。这些结果有助于理解白杨2n卵的形成机理，并使2n卵在多倍体白杨育种中的利用更加有效。
Three synthetic triploid seedlings were derived from a cross between maternal parentPopulus×euramericana(Dode) Guinier andPopulus nigravar.italica(Moench.) Koehne via embryo rescue by treating female floral buds with colchicine at certain developmental stages before and after pollination, and identified by flow cytometric analyses. A total of 21 microsatellite primers were used to infer the ploidy of gametes forming the hybrids and the underlying meiotic mechanism. The results suggest that 2n eggs originated from the maternal poplar, contributing the extra haploid genome in the triploids. In addition, first division restitution (FDR) 2n eggs were produced in the maternal tree according to the marker genotypes of these triploids. Cytological analyses of megasporogenesis revealed that meiosis of the maternal parent was asynchronous. This cytological evidence suggests that 2n eggs result from FDR after treatment with colchicine, as a portion of megaspore mother cells (MMCs) were within the first division at the post-pollination stage. These results aid in understanding the mechanism of 2n egg formation in poplar and make the utilization of 2n eggs in polyploid poplar breeding more effectively.