IDENTIFICATION OF THE PARENTAL CHROMOSOMES OF THE WHEAT-ALIEN AMPHIPLOID AGROTANA BY GENOMIC IN-SITU HYBRIDIZATION

Labelled total genomic DNA from four alien species, Thinopyrum ponticu m (Host) Beauv. (2n = 70, genomes J(1)J(1)J(1)J(2)J(2)), Th. bessarabi cum (Savul. & Rayss) Love (2n = 14, genome J), Th. elongatum (Host) Be auv. (2n = 14, genome E), Haynaldia villosa (L.) Schur. (2n = 14, geno me V), were used as probes in combination with blocking wheat DNA for in situ hybridization of the chromosomes of Agrotana, a wheat-alien hy brid (2n = 56) of unknown origin. The results showed that genomic DNA probes from Th. ponticum and Th. bessarabicum both clearly revealed 16 alien and 40 wheat chromosomes in Agrotana, indicating that the J gen ome present in these two species has a high degree of homology with th e alien chromosomes in Agrotana. Biotinylated genomic DNA probe from T h. elongatum identified 10 chromosomes from Agrotana, while some regio ns of six other chromosomes yielded a weak or no signal. The probe fro m H. villosa produced no differential labelling of the chromosomes of Agrotana. The genomic formula of Agrotana was designated as AABBDDJJ. We suggest that the alien parent donor species of Agrotana is Th. pont icum rather than Th. bessarabicum. Genomic relationships of the three Thinopyrum species are discussed in relation to the distribution of GI SH signals in the chromosomes of Agrotana.