It has been hypothesized that the powdery mildew adult plant resistance (APR) controlled by the Pm13 gene in Aegilops longissima Schweinf. & Muschl. (SlSl) has been evolutionary transferred to Aegilops variabilis Eig. (UUSS). The molecular marker analysis and the visual evaluation of powdery mildew symptoms in Ae. variabilis and the Ae. variabilis × Secale cereale amphiploid forms (2n = 6x = 42, UUSSRR) showed the presence of product that corresponded to Pm13 marker and the lower infection level compared to susceptible model, respectively. This study also describes the transfer of Ae. variabilis Eig. (2n = 4x = 28, UvUvSvSv) chromosomes, carrying powdery mildew resistance, into triticale (× Triticosecale Wittm., 2n = 6x = 42, AABBRR) using Ae. variabilis × S. cereale amphiploid forms. The individual chromosomes of Ae. variabilis, triticale ‘Lamberto’ and hybrids were characterized by genomic and fluorescence in situ hybridization (GISH/FISH). The chromosome configurations of obtained hybrid forms were studied at first metaphase of meiosis of pollen mother cells (PMCs) using GISH. The statistical analysis showed that the way of S-genome chromosome pairing and transmission to subsequent hybrid generations was diploid-like and had no influence on chromosome pairing of triticale chromosomes. The cytogenetic study of hybrid forms were supported by the marker-assisted selection using Pm13 marker and visual evaluation of natural infection by Blumeria graminis, that allowed to select the addition or substitution lines of hybrids carrying chromosome 3Sv which were tolerant to the powdery mildew infection.

Segregation distorters are curious, evolutionarily selfish genetic elements, which distort Mendelian segregation in their favor at the expense of others. Those agents include gametocidal factors (Gc), which ensure their preferential transmission by triggering damages in cells lacking them via chromosome break induction. Hence, we hypothesized that the gametocidal system can be adapted for chromosome manipulations between Triticum and Secale chromosomes in hexaploid triticale (×Triticosecale Wittmack). In this work we studied the little-known gametocidal action of a Gc factor located on Aegilops geniculata Roth chromosome 4Mg. Our results indicate that the initiation of the gametocidal action takes place at anaphase II of meiosis of pollen mother cells. Hence, we induced androgenesis at postmeiotic pollen divisions (via anther cultures) in monosomic 4Mg addition plants of hexaploid triticale (AABBRR) followed by production of doubled haploids, to maintain the chromosome aberrations caused by the gametocidal action. This approach enabled us to obtain a large number of plants with two copies of particular chromosome translocations, which were identified by the use of cytomolecular methods. We obtained 41 doubled haploid triticale lines and 17 of them carried chromosome aberrations that included plants with the following chromosome sets: 40T+Dt2RS+Dt2RL (5 lines), 40T+N2R (1), 38T+D4RS.4BL (3), 38T+D5BS-5BL.5RL (5), and 38T+D7RS.3AL (3). The results show that the application of the Gc mechanism in combination with production of doubled haploid lines provides a sufficiently large population of homozygous doubled haploid individuals with two identical copies of translocation chromosomes. In our opinion, this approach will be a valuable tool for the production of novel plant material, which could be used for gene tracking studies, genetic mapping, and finally to enhance the diversity of cereals.

Triticum genus encloses several tetraploid species that are used as genetic stocks for expanding the genetic variability of wheat (Triticum aestivum L.). Although the T. aestivum (2n = 6x = 42, AABBDD) and T. durum (2n = 4x = 28, AABB) karyotypes were well examined by chromosome staining, Giemsa C-banding and FISH markers, other tetraploids are still poorly characterized. Here, we established and compared the fluorescence in situ hybridization (FISH) patterns on chromosomes of 20 accessions of T. polonicum species using different repetitive sequences from BAC library of wheat ‘Chinese Spring’. The chromosome patterns of Polish wheat were compared to tetraploid (2n = 4x = 28, AABB) Triticum species: T. durum, T. diccocon and T. turanicum, as well. A combination of pTa-86, pTa-535 and pTa-713 probes was the most informative among 6 DNA probes tested. Probe pTa-k374, which is similar to 28S rDNA sequence enabled to distinguish signal size and location differences, as well as rDNA loci elimination. Furthermore, pTa-465 and pTa-k566 probes are helpful for the detection of similar organized chromosomes. The polymorphisms of signals distribution were observed in 2A, 2B, 3B, 5B, 6A and 7B chromosomes. Telomeric region of the short arm of 6B chromosome was the most polymorphic. Our work is novel and contributes to the understanding of T. polonicum genome organization which is essential to develop successful advanced breeding strategies for wheat. Collection and characterization of this germplasm can contribute to the wheat biodiversity safeguard.