Othmeni Manel, Grewal Surbhi, Walker Jack, Yang Cai-Yun, King Ian P, King Julie
School of Biosciences, The University of Nottingham, Sutton Bonington Campus, Loughborough, United Kingdom.
Front Plant Sci. 2022 Jul 7;13:927728. doi: 10.3389/fpls.2022.927728. eCollection 2022.
, the D-genome donor of hexaploid wheat, provides a source of genetic variation that could be used for tetraploid (durum) wheat improvement. In addition to the genes for wheat quality on the D-genome, which differentiate between bread and durum wheats in terms of end-use properties, genes coding for resistances to biotic and abiotic stresses are also present on the D-genome which would be useful in durum wheat. The introgression of into durum wheat, however, requires cytogenetic manipulation to induce homoeologous chromosome pairing to promote recombination. For this purpose, the introgression of into durum wheat was performed through a bridge cross of the wild species to the Langdon 5D(5B) disomic substitution line that lacks the locus present on chromosome 5B, followed by a cross of the F to the durum wheat cultivar Om Rabi 5. Subsequent generations were self-fertilized, and these were screened for D-genome introgressions using (i) D-genome-specific Kompetitive Allele-Specific PCR (KASP) markers and (ii) KASP markers polymorphic between the 5D chromosomes of wheat, present in the Langdon 5D(5B) substitution line, and of . Homozygous introgression lines were confirmed using genomic and fluorescence hybridization. The results showed that the use of the Langdon 5D(5B) disomic substitution line did not promote D-genome introgression across all linkage groups with only a limited success in the introgression of 5D segments into durum wheat.
六倍体小麦的D基因组供体提供了一种遗传变异来源，可用于四倍体（硬粒）小麦的改良。除了D基因组上决定面包小麦和硬粒小麦最终用途特性差异的小麦品质基因外，D基因组上还存在编码对生物和非生物胁迫抗性的基因，这些基因对硬粒小麦很有用。然而，将其导入硬粒小麦需要进行细胞遗传学操作，以诱导部分同源染色体配对来促进重组。为此，通过将野生种与缺乏5B染色体上存在的位点的Langdon 5D(5B)二体代换系进行桥梁杂交，然后将F1与硬粒小麦品种Om Rabi 5杂交，将导入硬粒小麦。随后的世代进行自交，并使用（i）D基因组特异性竞争性等位基因特异性PCR（KASP）标记和（ii）在Langdon 5D(5B)代换系中存在的小麦5D染色体与的5D染色体之间多态性的KASP标记筛选D基因组导入。使用基因组和荧光原位杂交确认纯合导入系。结果表明，使用Langdon 5D(5B)二体代换系并不能促进D基因组在所有连锁群中的导入，只有将5D片段导入硬粒小麦时取得了有限的成功。
