| Male-sterile durum: Interaction of Triticum boeoticum
and T. monococcum cytoplaslms with T. durum nucleus1)
S. S. MAAN and K. A. LUCKEN Agronomy Department, North Dakota State University Fargo, North Dakota, U.S.A. Earlier, male sterility of 2n=28 (14II) chromosome plants with the pedigree (T. boeoticum-type x T. durum) was reported (MAAN and LUCKEN, WIS Nos. 23-24 : 6-9, 1967). Further backcrosses have been accomplished and, even after six backcrosses, plants with T. boeoticum-type cytoplasm do not resemble the recurrent T. durum (N. Dak. accession 56-1) male parent. These male-sterile plants have thinner and weaker straw, narrower and shorter leaves, narrower heads, shorter and weaker awns, smaller seeds and more tillers than the T. durum parent. In each of the backcross generations an apparent segregation for weak and dwarf plants occurred and only relatively strong plants were selected for subsequent backcrosses. Because the T. boeoticum-type plant used in the above cross was of doubtful origin, we also are substituting the chromosomes of T. durum and T. aestivum into the cytoplasms of T. boeoticum, T. monococcum and several amphidiploids involving these two species to observe male sterility effects. At the time of the present report, male-sterile plants with the pedigree female T. monococcum x male T. durum3 and four have been obtained. These plants have 2n=28 (14II) chromosomes and do not yet resemble phenotypically the recurrent T. durum parent. Further backcrosses will be continued to accomplish complete substitution of T. durum and T. aestivum genomes into the cytoplasm of diploid wheats. (Received Jan. 23, 1968) |
| 1) Published with the approval of the Director, North Dakota Agricultural Experiment Station, as Journal Article No. 127. |