| Results The haploid genotype of Chinese Spring was established as ch1Ch2Ne1wne2d1d2d3. This genotype is identical with the Chinese Spring line investigated by HERMSEN (1963a, 1963b, 1966, 1967). Ch2/ch2 has been located on 3D (TSUNEWAKI and KIHARA 1961) and D3/d3 On 4B (HURD and MCGINNIS 1958, HERMSEN 1963b). If 2M carries Ch1 all artifacts should have the genotype Ch1Ch1Ch2Ch2 and this would have led to chlorotic plants (HERMSEN 1966). This was not the case. So 2M does not carry Ch1. The same holds good for the Ne2s-allele because plants having the genotype Ne1wNe1wNe2sNe2s would be necrotic (HERMSEN 1963b). Artifacts 87, 88 and 89 were crossed with an Ne1s-carrier. If 2M carries a dominant Ne2-allele necrotic plants would have been found in the F1's and/or F2's. They were not discovered so 2M does not carry Ne2. Artifact 90 was crossed with Amby (d1D2D3, HERMSEN 1967), and artifacts 87 and 89 with Kenya Farmer (D1d2D3, HERMSEN, 1963b, 1967) to try and find D1 and D2 genes. If artifact 90 had carried D1 the F1 would have been dwarfed. The same is true if artifacts 87 and 89 had carried D2. No dwarf plants were observed neither in any F1 normal in any F2 so 2M does not carry D1 and D2. All artifacts were crossed with T. timopheevi-cytoplasmic male sterile plants. No F1 plant produced seeds and this indicates that 2M does not carry an Rf gene. It may be concluded that 2M of the Ae. comosa-source investigated does not carry Ch1, Ne2, D1, D2 and Rf. It is not known whether there are loci for the recessive alleles. The only similarity is the presence of genes for yellow rust resistance on 2A (II) of Thatcher and on 2M. Of course, the compensation for the loss of a pair of wheat chromosomes by a pair of 2M chromosomes suggests that there are genes common to 2M and the wheat chromosomes. Literature Cited HERMSEN, J. G. Th. 1963a. Hybrid necrosis as a problem for the wheat breeder. Euphytica 12: 1-16. HERMSEN, J. G. 1963b. The localization of two genes for dwarfing in the wheat variety Timstein by means of substitution lines. Euphytica 12: 126-129. HERMSEN, J. G. 1966. Hybrid necrosis and red hybrid chlorosis in wheat. Proc. 2nd Intern. Wheat. Genet. Symp., Lund 1963. Hereditas Suppl. 2: 439-452. HERMSEN, J. G. 1967. Hybrid dwarfness in wheat. Euphytica 16: 134-162. HURD, E. A. and R. C. MCGINNIS 1958. Note on the localization of genes for dwarfing in Redman wheat. Can. J. Pl. Sci. 38: 506. RILEY, R., V. CHAPMAN and R. JOHNSON 1968. Introduction of yellow rust resistance of Aegilops comosa into wheat by genetically induced homoeologous recombination. Nature 217: 383-384. TALAAT, E. H. 1969. Chromosomal location of genes controlling pollen fertility restoration in three restorer lines of wheat. Dissertation, North Dakota State University of Agriculture and Applied Science, Fargo, N. D., U.S.A. TSUNEWAKI, K. 1960. Monosomic and convential gene analysis in common wheat. II. Lethality. Jap. J. Genet. 35: 71-75. TSUNEWAKI, K. and H. KIHARA 1961. F1 monosomic analysis of T. macha. Wheat Inform. Serv. 12: 1-3. UNRAU, J. 1950. The use of monosomics and nullisomics in cytogenetic studies of common wheat. Sci. Agric. 30: 66-89. WELSH, J. R., E. L. SHARP and E. R. HEHN 1965. Stripe rust investigations. 1964-Wheat Newsletter 11: 64-65. (Received March 16, 1970) |
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