Characterization of six wheat × Thinopyrum intermedium derivatives by GISH, RFLP, and multicolor GISH

Restriction fragment length polymorphism (RFLP) analysis and multicolor genomic in situ hybridization (GISH) are useful tools to precisely characterize genetic stocks derived from crosses of wheat (Triticum aestivum) with Thinopyrum intermedium and Thinopyrum elongatum. The wheat × Th. intermedium derived stocks designated Z1, Z2, Z3, Z4, Z5, and Z6 were initially screened by multicolor GISH using Aegilops speltoides genomic DNA for blocking and various combinations of genomic DNA from Th. intermedium, Triticum urartu, and Aegilops tauschii for probes. The probing (GISH) results indicated that lines Z1 and Z3 were alien disomic addition lines with chromosome numbers of 2n = 44. Z2 was a substitution line in which chromosome 2D was substituted by a pair of Th. intermedium chromosomes; this was confirmed by RFLP and muticolour GISH. Z4 (2n = 44) contained two pairs of wheat – Th. intermedium translocated chromosomes; one pair involved A-genome chromosomes, the other involved D- and A-genome chromosomes. Z5 (2n = 44) contained one pair of wheat – Th. intermedium translocated chromosomes involving the D- and A-genome chromosomes of wheat. Z6 (2n = 44) contained one pair of chromosomes derived from Th. intermedium plus another pair of translocated chromosomes involving B-genome chromosomes of wheat. Line Z2 was of special interest because it has some resistance to infection by Fusarium graminearum.Key words: wheat, Thinopyrum intermedium, addition, substitution, and translocation lines, GISH, multicolor GISH, RFLP.