Molecular cytogenetic identification of a new synthetic amphiploid (Triticum timococcum, A^tA^tGGA^mA^m) with a seed setting rate comparable with that of natural Triticum zhukovskyi

Abstract

Triticum timopheevii (AtAtGG) was previously cultivated in western Georgia, and Triticum zhukovskyi (AtAtGGAmAm) is a natural allohexaploid originating from hybridization of T. timopheevii and Triticum monococcum (AmAm). In this study, two synthetic amphiploids (Triticum timococcum, AtAtGGAmAm), Syn‐AtGAm‐20 and Syn‐AtGAm‐21, were developed by chromosome doubling of F1 hybrids between T. timopheevii and T. monococcum. Chromosomes of these two amphiploids were identified by fluorescence in situ hybridization (FISH) utilizing oligonucleotide probes Oligo‐pSc119.2‐1, Oligo‐pTa535‐1, Oligo‐pTa71‐2 and Oligo‐(AAC)7. Each amphiploid had 42 chromosomes derived from its parents, but the Glu‐A1mx subunits from einkorn were both not expressed. Syn‐AtGAm‐20 had low average seed setting rates of 19.86% and 20.50% in two different years, with abnormal spikes similar to those reported before. Syn‐AtGAm‐21 had normal spikes with average seed setting rates of 65.88% and 61.56% in two different years, comparable with those of natural T. zhukovskyi. However, the relationship between Syn‐AtGAm‐21 and natural T. zhukovskyi requires further study. This research provides new materials for studying the origin of T. zhukovskyi.