Alien Chromosome Addition in Wheat1
- Jurgen Schulz-Schaeffer and
- F. H. McNeal2
Alien chromosome addition in the tetraploid wheat Triticum turgidum L. var. durum (AABB) is proposed. An Agrotricum with the constitution AABBII is anticipated. The I genome could consist of any group of seven chromosomes from Agropyron intermedium (Host) Beauv. The amphiploid derivative parent was an F10 strain with an average chromosome number of 2n = 49 (range 25 to 66) resulting from chromosome elimination. Eleven first-nuclear-restoration backcross plants (RB1) to the amphiploid of Triticum turgidum L. var. durum (2n = 28) ✕ A. intermedium (Host) Beauv. (2n = 42) have been established. The 11 RB1 plants had a mean chromosome number per cell of 2n = 37.8, with a range of 25 to 50. The mean frequency of bivalent pairing per cell was 10.4 with a range of 0 to 21. The mean univalent number per cell was 17.0, ranging from 2 to 45. The RB1 plants generally had morphological characteristics intermediate between the amphiploid and durum parents, pollen fertility of the RB1's averaged 8.1%, with a range of 0.3 to 35.6%. Further backcrossing of the RB1 material with the durum parent is planned. Selection among RB2 plants for high pollen fertility and a high stable number of univalents will be followed by RB2 ✕ RB1 intercrossing and finally selfing for the elimination of undesirable Agropyron univalents. A final product with 2n = 42 and genome formula AABBII is anticipated from this program.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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