Abstract

Alien chromosome lines were developed and identified from the BC₁F₂ and BC₁F₃generations of a wheat-Psathyrostachys huashanica intergeneric cross. Their agronomic traits were evaluated in the field and their meiotic behaviors and chromosome composition were analyzed by cytogenetic and GISH (genomic in situhybridization) techniques. Five lines with 2n = 44 and one line with 2n = 46 showed regular meiosis and were cytologically stable. Based on chromosome pairing, C-banding and GISH analysis, lines 156-4, 160-12, 160-13, 173-2 and 197-16 (2n = 44) were alien disomic addition lines with the addition of one pair of the P. huashanica 5Ns chromosomes. Line 165-2, which had each pair of the P. huashanica chromosomes 3Ns and 5Ns being added, was an alien double addition line. Nine lines with the P. huashanica chromosome 1Ns, 2Ns, 4Ns or 5Ns werealien monosomic addition lines. Robertsonian translocation was observed in lines 241-2 and 241-10. Some chromosomal abnormalities were observed such as telosomics, lagging of telosomics and telosomic sister chromatids that moved to one pole at anaphase I and asynchronous chromosome separation at telophase II. These results indicated that, the presence of alien chromosomes from P. huashanica had influenced the meiosis. Meanwhile, by comparing the series of wheat-P. huashanica chromosome addition lines, the gene(s) for awns were mapped on the P. huashanica 5Ns chromosome.

Key words: Alien addition lines, giemsa C-banding, genomic in situ hybridization,Psathyrostachys huashanica Keng ex Kuo, bread wheat.