Abstract:
Utilization of crop wild relatives of wheat can be very effective in building the genetic diversity to cater to the evolving strains of disease pathogens. Aegilops speltoides is a rich source of rust resistance genes however transferring those to wheat genome can be tedious due to co-transfer and preferential transmission of undesirable genes causing gametocidal activity. Such an unholy association was observed in Triticum aestivum-Ae. speltoides derivative line Sel. 2427 which possess the broad-spectrum leaf rust seedling resistance gene (LrS2427). Molecular analysis based on 35 K wheat breeder\'s array revealed the maximum percentage of Ae. speltoides genome introgression on homoeologous group 2. In situ hybridization studies revealed the presence of S genome in Sel. 2427, showing six translocations on four chromosomes. Karyotyping using repetitive probe (AAG)6 revealed that the two chromosomes involved are 2D and 2B. Genic regions causing gametocidal activity were identified by dissecting it into component traits and QTLs on 2D and 2B chromosomes were revealed in case of the trait seed shrivelling index. To break the inadvertent association of LrS2427 with gametocidal genes, F1(Agra Local X Sel. 2427) seeds were irradiated with gamma rays and stable leaf rust resistant mutants lacking gametocidal activity were developed. These mutants showed resistance to different races of leaf rust pathogen and showed superior agronomic performance as well. These mutants could be a great resource in wheat improvement for utilization of the leaf rust resistance gene LrS2427 without any yield penalty.
UNASSIGNED: The online version contains supplementary material available at 10.1007/s11032-024-01491-8.
摘要:
利用小麦的作物野生近缘种可以非常有效地建立遗传多样性,以适应不断发展的疾病病原体菌株。Aegilopsspeltoides是抗锈病基因的丰富来源,但是将这些基因转移到小麦基因组中可能是繁琐的,因为不希望的基因的共同转移和优先传递会导致杀配子活性。在普通小麦中观察到了这种邪恶的关联。speltoides衍生线Sel。2427具有广谱抗叶锈病幼苗抗性基因(LrS2427)。基于35K小麦育种者阵列的分子分析揭示了Ae的最大百分比。同源组2上的speltoides基因组渗入。原位杂交研究显示Sel中存在S基因组。2427,在四个染色体上显示六个易位。使用重复探针(AAG)6进行的核型分析显示,涉及的两个染色体是2D和2B。通过将其分解为组分性状来鉴定引起杀配子活性的基因组区域,并在性状种子枯萎指数的情况下揭示了2D和2B染色体上的QTL。为了打破LrS2427与杀配子基因的无意关联,F1(阿格拉本地X塞尔。2427)用γ射线辐照种子,并开发了缺乏杀配子活性的稳定的抗叶锈病突变体。这些突变体对不同品种的叶锈病病原体表现出抗性,并表现出优异的农艺性能。这些突变体可能是小麦改良中利用叶锈病抗性基因LrS2427的重要资源,而不会造成任何产量损失。
■在线版本包含补充材料,可在10.1007/s11032-024-01491-8获得。