*Communication* **Recovery of 2R.2S<sup>k</sup> Triticale-***Aegilops kotschyi* **Robertsonian Chromosome Translocations**

### **Waldemar Ulaszewski 1, Jolanta Belter 1, Halina Wi´sniewska 1, Joanna Szymczak 2, Roksana Skowro ´nska 2, Dylan Phillips 3 and Michał T. Kwiatek 1,\***


Received: 9 September 2019; Accepted: 15 October 2019; Published: 17 October 2019

**Abstract:** Robertsonian translocations (RobTs) in the progeny of triticale (×*Triticosecale* Wittmack) plants with monosomic substitution of *Aegilops kotschyi* chromosome 2S<sup>k</sup> (2R) were investigated by fluorescence in-situ hybridization. Chromosome 2S<sup>k</sup> of *Ae. kotschyi* is reported to possess many valuable loci, such as *Lr54* + *Yr37* leaf and stripe (yellow) rust resistance genes. We used a standard procedure to produce RobTs, which consisted of self-pollination of monosomic triticale plants, carrying 2R and 2S<sup>k</sup> chromosomes in monosomic condition. This approach did not result in RobTs. Simultaneously, we succeeded in producing 11 plants carrying 2R.2S<sup>k</sup> compensatory RobTs using an alternative approach that utilized ditelosomic lines of triticale carrying 2RS (short arm) and 2RL (long arm) telosomic chromosomes. Identification of molecular markers linked to *Lr54* + *Yr37* genes in the translocation plants confirmed that these resources can be exploited in current triticale breeding programmes.

**Keywords:** *Aegilops*; centric breaks; chromosome fusion; Robertsonian translocations; telosomic chromosomes; triticale
