CHROMOSOME CONSTITUTIONS OF WHEAT-THINOPYRUM AMPHIPLOIDS WITH PERENNIAL GROWTH HABIT

¹Department of Crop and Soil Sciences, Washington State University, Pullman, WA 99164 USA
²Department of Plant Pathology, Washington State University, Pullman, WA 99164 USA

Perennial wheat is being studied as a tool for erosion control. Three wheat-Thinopyrum amphiploids, AT 3425 (2n=56), PI 550713 (2n=56), and AgCs (2n=56) were identified to be perennial. AT 3425 was identified to have seven pairs of Thinopyrum chromosomes, three pairs of wheat-Thinopyrum translocated chromosomes and 18 pairs of wheat chromosomes and thought to be derived from a cross between wheat and Th. ponticum (Podp) Barkworth & D. R. Dewey (2n=10x=70). Fluorescence genomic in situ hybridization (FGISH) patterns of somatic chromosomes in PI 550713 demonstrated that PI 550713 also carried seven pairs of Thinopyrum chromosomes, three pairs of wheat-Thinopyrum translocated chromosomes and 18 pairs of wheat chromosomes. Chromosome pairing in the hybrid between AT 3425 and PI 550713 indicated that PI 550713 is likely to have the same chromosome constitution as AT 3425. AgCs was reported to be produced from a cross between Triticum aestivum L. cv. 'Chinese Spring' and Th. elongatum (Host) D. R. Dewey (2n=2x=14) and have seven pairs of Thinopyrum chromosomes and 21 pairs of wheat chromosomes. FGISH patterns of meiotic chromosomes in the hybrid between AgCs and AT 3425 revealed that Thinopyrum chromosomes in AgCs and AT 3425 were derived from different Thinopyrum species, i.e. Thinopyrum chromosomes in AgCs and AT 3425 were from Th. elongatum and Th. ponticum, respectively. Determination of chromosome constitutions in these perennial amphiploids will be valuable for further manipulation of perennial growth habit in wheat.