Abstract
Background
Psathyrostachys huashanica Keng (2n = 2x = 14, NsNs) is a rare and unique species of grass that is native to China. It is a significant genetic resource for wheat breeding because of the multiple beneficial features that can be used in wheat improvement programs.
Results
The study isolated a novel wheat - P. huashanica derived line 18TR61 from the progeny of common wheat 7182 and P. huashanica. Cytological studies revealed that 18TR61 has chromosome karyotype of 2n = 42 = 21II; Genomic in situ hybridization (GISH) and non-denaturing fluorescence in situ hybridization (ND-FISH) experiments confirmed that two 2D chromosomes in line 18TR61 were replaced by two incomplete Ns chromosomes. Meanwhile, it has been observed that 18TR61 exhibits structural variations in chromosomes 2B, 7B, and 5A when compared to its parents. Molecular markers and GenoBaits®WheatplusPh microarray analysis indicated that the alien chromosomes originated from P. huashanica 2Ns. Based on karyotype observations, it was incomplete in length, and contains all of the short arm, centromere, and fragment of the long arm. Assessment of agronomic traits showed that 18TR61 outperformed its parents in terms of stripe rust resistance in the adult plant stage, as well as spike length and grain size.
Conclusions
As a result, 18TR61 was identified as a wheat - P. huashanica 2NsS (2D) fragment disomic substitution. Furthermore, the established 15 specific markers were beneficial for the quick identification of heterologous material containing the 2Ns chromosome in the wheat background. This line offered a possible bridge for wheat genetic improvement on disease resistance to stripe rust and yield.