Isolation and Characterization of a Psathyrostachys huashanica Keng 6Ns Chromosome Addition in Common Wheat

The development of alien addition lines is important for transferring useful genes from exotic species into common wheat. A hybrid of common wheat cv. 7182 (2n = 6x = 42, AABBDD) and Psathyrostachys huashanica Keng (2n = 2x = 14, NsNs) via embryo culture produced the novel intergeneric disomic addition line 59-11. The seed morphology of 59-11 resembled the parent 7182 and it exhibited extreme agronomic characteristics, i.e., twin stable spikelets, fertile florets, and multi-kernel clusters. Furthermore, 59-11 produced plump kernels with a high seed-setting percentage during the advanced maturation stage. The line was screened based on genomic in situ hybridization, EST-SSR, EST-STS, and gliadin to identify P. huashanica chromatin in the wheat background. The chromosome number and configuration of 59-11 was 2n = 44 = 22 II and we confirmed the 6Ns disomic chromosome additions based on A-PAGE analysis and molecular markers. The results suggested that the production of twin spikelets and multiple kernels per spike in the wheat-P. huashanica addition line was related to homologous group 6 in the wheat chromosome. This is the first report of the introduction of improved spike traits into common wheat from the alien species P. huashanica and it opens up the possibility of increasing the wheat yield based on this enlarged gene pool.