School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, Jiangsu, China.
Jiangsu Xuhuai Regional Xuzhou Institute of Agricultural Sciences, Chinese Academy of Agricultural Sciences, Xuzhou 221121, Jiangsu, China.
Genome. 2022 Jun 1;65(6):331-339. doi: 10.1139/gen-2021-0088. Epub 2022 Mar 7.
Cultivated sweetpotato [ (L.) Lam.] from the family Convolvulaceae is a hexaploid species with 2 = 6 = 90 and has been controversial regarding its nature as an autopolyploid arising within a species or an allopolyploid forming between species. Here, we developed oligonucleotide-based painting probes for two chromosomes of , a model diploid species. Using these probes, we revealed the pairing behavior of homoeologous chromosomes in and its two possible polyploid ancestral species, tetraploid (2 = 4 = 60) and hexaploid (2 = 6 = 90). Chromosome painting analysis revealed a high percentage of quadrivalent formation in zygotene-pachytene cells of , which supported that was an autotetraploid likely derived by doubling of structurally similar and homologous genomes rather than a hybrid between and (2). A high frequency of hexavalent/bivalent and tetravalent pairing was observed in (6) and . However, the percentage of hexavalent pairing in (6) was far higher than that in . Thus, the present results tend to support that (6) is an autohexaploid, while is more likely to be a segmental allohexaploid.
栽培番薯（L.）Lam. 来自旋花科，是一个六倍体物种，2 = 6 = 90，关于其作为物种内的同源多倍体还是物种间的异源多倍体的性质一直存在争议。在这里，我们为模式二倍体物种 开发了基于寡核苷酸的两条染色体的涂抹探针。使用这些探针，我们揭示了同源染色体在 和其两个可能的多倍体祖先物种，四倍体 （2 = 4 = 60）和六倍体 （2 = 6 = 90）中的配对行为。染色体涂抹分析显示 在合线期-粗线期细胞中形成了很高比例的四价体，这支持 是一个同源四倍体，可能是通过结构相似和同源基因组的加倍而不是 和 （2）之间的杂种产生的。在 （6）和 中观察到很高比例的六价体/二价体和四价体配对。然而，在 （6）中六价体配对的百分比远高于 。因此，目前的结果倾向于支持 （6）是一个同源六倍体，而 更可能是一个片段异源六倍体。
