Rare instances of haploid inducer DNA in potato dihaploids and ploidy-dependent genome instability
Rare instances of haploid inducer DNA in potato dihaploids and ploidy-dependent genome instability
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DOI：
10.1093/plcell/koab100
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发表时间：
2021-04-01
期刊：
影响因子：
11.6
通讯作者：
Comai, Luca
中科院分区：
文献类型：
--
作者：
Amundson, Kirk R.;Ordonez, Benny;Comai, Luca
在栽培的四倍体马铃薯（Solanum tuberosum）中，还原为二倍体（dihaploidy）允许与二倍体杂交和渐渗育种，并可能促进近交系的产生。用单倍体诱导剂（Hs）授粉产生母本二单倍体，以及三倍体和四倍体杂种。双单倍体可能是由单性生殖（导致未受精卵发育成胚胎）或基因组消除（导致错误分离和父本染色体丢失）产生的。基因组消除的一个标志是 HI DNA 在一些双单倍体中偶尔持续存在。我们对 919 个假定的二单倍体和 134 个杂交体的基因组进行了特征分析，这些杂交体是通过用三个 Hls：IVP35、IVP101 和 PL-4 授粉四倍体克隆产生的。在 76 个二单倍体中观察到全染色体或节段非整倍性，核型范围从 2n = 2x - 1=23 到 2n = 2x + 3 = 27。在 74 个非整倍体的附加染色体中，66 个来自非诱导亲本，8 个来自诱导亲本。总体而言，无论亲本基因型如何，我们在 0.87% 的双单倍体中检测到来自 HI 亲本的完整或部分染色体。染色体断裂通常影响二单倍体和四倍体后代的父本基因组，但不影响三倍体后代，这将不稳定性与精子倍性和单倍体诱导相关。在后代中发现的残留 HI DNA 与基因组消除作为单倍体诱导机制一致。
In cultivated tetraploid potato (Solanum tuberosum), reduction to diploidy (dihaploidy) allows for hybridization to diploids and introgression breeding and may facilitate the production of inbreds. Pollination with haploid inducers (Hs) yields maternal dihaploids, as well as triploid and tetraploid hybrids. Dihaploids may result from parthenogenesis, entailing the development of embryos from unfertilized eggs, or genome elimination, entailing missegregation and the loss of paternal chromosomes. A sign of genome elimination is the occasional persistence of HI DNA in some dihaploids. We characterized the genomes of 919 putative dihaploids and 134 hybrids produced by pollinating tetraploid clones with three Hls: IVP35, IVP101, and PL-4. Whole-chromosome or segmental aneuploidy was observed in 76 dihaploids, with karyotypes ranging from 2n = 2x - 1=23 to 2n = 2x + 3 = 27. Of the additional chromosomes in 74 aneuploids, 66 were from the non-inducer parent and 8 from the inducer parent. Overall, we detected full or partial chromosomes from the HI parent in 0.87% of the dihaploids, irrespective of parental genotypes. Chromosomal breaks commonly affected the paternal genome in the dihaploid and tetraploid progeny, but not in the triploid progeny, correlating instability to sperm ploidy and to haploid induction. The residual HI DNA discovered in the progeny is consistent with genome elimination as the mechanism of haploid induction.