Transfer of small chromosome fragments of Agropyron elongatum to wheat chromosome via asymmetric somatic hybridization.

The chromosome constitution of hybrids and chromatin patterns of Agropyron elongatum (Host)Neviski in F5 somatic hybrid lines II -1-3 and I-1-9 between Triticum aestivum L. and A. elongatum were analyzed. Based on the statistic data of pollen mother cells, F5 I-1-9 and II-1-3 had 20-21 bivalents with a frequency of 84.66% and 85.28%, of which, 89.83% and 89.57% were ring bivalents. The result indicated that both hybrid lines were basically stable in the chromosome constitution and behavior. RAPD analysis showed that the two hybrids contained biparental and integrated DNA. GISH (Genome in situ hybridization) revealed that in the form of small chromosome segments, A. elongatum chromatin was scattered on 4-6 wheat chromosomes near by the region of centromere and telomere in the two hybrid lines. SSR analysis indicated that A. elongatum DNA segments were distributed on the 2A, 5B, 6B and 2D wheat chromosomes in the hybrids, which was in accordance with the GISH results that small-segments intercalated poly-site.