Cytoplasmic male sterility (CMS) phenomenon is widely exploited in commercial hybrid seed production in economically important crop species, including rye, wheat, maize, rice, sorghum, cotton, sugar beets, and many vegetables. Although some commercial successes, little is known about QTLs responsible for the trait in case of triticale with sterilizing Triticum timopheevii (Tt) cytoplasm. Recombinant inbred line (RIL) F6 mapping population encompassing 182 individuals derived from the cross of individual plants representing the HT352 line and cv Borwo was employed for genetic map construction using SNP markers and identification of QTLs conferring pollen sterility in triticale with CMS Tt. The phenotypes of the F1 lines resulting from crossing of the HT352 (Tt) with HT352 (maintainer) × Borwo were determined by assessing the number of the F2 seeds per spike. A genetic map with 21 linkage groups encompasses 29,737 markers and spanned over the distance of 2549 cM. Composite (CIM) and multiple (MIM) interval mappings delivered comparable results. Single QTLs mapped to the 1A, 1B, 2A, 2R, 3B, 3R, 4B, and 5B chromosomes, whereas the 5R and 6B chromosomes shared 3 and 2 QTLs, respectively. The QTLs with the highest LOD score mapped to the 5R, 3R, 1B, and 4B chromosomes; however, the QRft-5R.3 has the highest explained variance of the trait.

Zjawisko cytoplazmatyczno-jądrowej męskiej sterylności (CMS) u roślin charakteryzuje się upośledzeniem rozwoju pełnowartościowego pyłku. To zaburzenie jest wynikiem niekompatybilności genomu mitochondrialnego i jądrowego. Istnieje wiele hipotez tłumaczących CMS, jednak molekularny mechanizm działania męskiej sterylności i przywracania płodności u większości gatunków roślin uprawnych pozostaje nieznany. Mimo to prace hodowców umożliwiły opracowanie wydajnych systemów CMS, które znalazły zastosowanie w hodowli między innymi zbóż. Zainteresowanie hodowlą heterozyjną wiąże się zarówno z możliwością wykorzystania efektu heterozji (poprzez krzyżowanie formy matecznej i ojcowskiej), jak  i z kontrolą nad materiałem siewnym. Ze względów ekonomicznych hodowla heterozyjna ma –  i należy oczekiwać, że będzie mieć – istotne znaczenie gospodarcze.

The Triticum timopheevii Zhuk. (Tt) cytoplasm is the most exploited cytoplasmic male sterility (CMS) type used in triticale in commercial seed production of hybrid varieties. The present study established a recombinant inbred line (RIL) mapping population to identify genetic loci controlling fertility restoration in triticale with CMS Tt. The trait was evaluated via phenotyping the BC 1 F 1 materials originating from a backcross of maternal line MS 112(15)-2-1 (on CMS Tt) and RILs. A genetic map spanning 2293 cM over 21 linkage groups was constructed using 1,170 single nucleotide polymorphisms and silico diversity array technology (DArT) markers generated through DArTseq genotyping. Two quantitative trait loci (QTL) controlling fertility restoration were localized at the 4RL chromosome. They were stable during two vegetative seasons and, depending on the year, explained 17.8 to 37.5 (QRft-4R.1) and 17.8 to 27.1% (QRft-4R.2) of phenotypic variance. Bioinformatic analysis was performed to predict genes potentially responsible for the trait. Four markers linked to the trait were successfully converted into a polymerase chain reaction-based assay to select the pollen fertility QTLs easily. The exact position of QTLs detected previously in the rye and here in the triticale suggests that the same loci might control the trait.

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