PDF(Pubmed)
Abstract：
Haploid induction (HI) holds great promise in expediting the breeding process in onion, a biennial cross-pollinated crop. We used the CENH3-based genome elimination technique in producing a HI line in onion. Here, we downregulated AcCENH3 using the RNAi approach without complementation in five independent lines. Out of five events, only three could produce seeds upon selfing. The progenies showed poor seed set and segregation distortion, and we were unable to recover homozygous knockdown lines. The knockdown lines showed a decrease in accumulation of AcCENH3 transcript and protein in leaf tissue. The decrease in protein content in transgenic plants was correlated with poor seed set. When the heterozygous knockdown lines were crossed with wild-type plants, progenies showed HI by genome elimination of the parental chromosomes from AcCENH3 knockdown lines. The HI efficiency observed was between 0 and 4.63% in the three events, and it was the highest (4.63%) when E1 line was crossed with wildtype. Given the importance of doubled haploids in breeding programmes, the findings from our study are poised to significantly impact onion breeding.
摘要：
单倍体诱导（HI）在加快洋葱的育种过程中具有很大的希望，一种两年生的异花授粉作物。我们使用基于CENH3的基因组消除技术在洋葱中产生HI系。这里,我们使用RNAi方法在没有互补的情况下在五个独立的细胞系中下调AcCENH3。在五个事件中，只有三个能在自交时产生种子。后代表现出不良的种子结实和分离畸变，我们无法恢复纯合敲除系。敲除品系显示AcCENH3转录物和蛋白质在叶组织中的积累减少。转基因植物中蛋白质含量的降低与种子结实不良有关。当杂合敲除系与野生型植物杂交时，后代通过从AcCENH3敲低品系中消除亲本染色体的基因组显示HI。在三个事件中观察到的HI效率在0和4.63%之间，E1系与野生型杂交时最高(4.63%)。鉴于加倍单倍体在育种计划中的重要性，我们的研究结果有望对洋葱育种产生重大影响。
