Inheritance of the Translocation in Chromosome 2D of Common Wheat from Aegilops speltoides Tausch with Leaf Rust Resistance Gene

Resumo

The variety of common spring wheat Chelyaba 75 carries a translocation from Aegilops speltoides Tausch in the chromosome 2D, which contains the leaf rust resistance gene and gametocidal genes. The length of this translocation was determined by molecular-genetic analysis. It is shown that the long arm of chromosome 2D is completely replaced by the long arm of chromosome 2S; it is possible that translocation involves the near-centromere region of the short arm. According to molecular analysis data, the translocation from Ae. speltoides in the Chelyaba 75 variety differs from the 2S chromosome region carrying the Lr35/Sr39 genes. This makes it possible to designate the leaf rust resistance gene of the Chelyaba 75 as LrSp2. The inheritance of LrSp2 in four populations from crossing Chelyaba 75 with different varieties of common wheat was studied. Estimation of leaf rust resistance of F₂ and F₃ hybrids in field conditions (2015–2016) revealed the absence of susceptible plants. The presence of 2DS.2SL translocation in hybrid plants was confirmed by molecular analysis. The results indicate the action of the gametocidal gene localized in the 2DS.2SL translocation and the fact that its tight linkage to the LrSp2 gene is inherited in a series of generations.