| The data of FELDMAN(1966) who found that all the telocentric chromosomes
of genome B of Chinese Spring tested paired to some extent with the corresponding
chromosomes of T. timopheevii, suggested that the second genome of
T. timopheevii (G) was closely related to the B genome of T. aestivum
and could have differentiated from the B genome as a result of exchanges
of the homoeologous chromosomal segments with other genomes. LILIENFELD
& KIHARA (1934) were the frist who specified by genome analysis that T.
timopheevii should be considered a species distinct from other tetraploid
wheat belonging to the emmer group and proposed for this species the genomic
formula AAGG. In our experiments the absence of chromosome 5B or locus Ph1 in hybrids from crosses between T. aestivum and tetraploid wheat species showed significant increase in the homoeologous pairing in wheat chromosomes . From the data of the present studies a conclusion may be drawn that the use of nulli-5B-tetra-5A Iine and mutant ph1 is an effective way to increase the rate of recombinations of genetic material and induce of homoeologous pairing of chromosomes not only in the wheat x rye hybrids, as it was shown by our experiments (SHNAIDER & PRIILlNN 1984), but also in interspecific hybrids between T. aestivum and tetraploids T. timopheevii and T. militinae. References FELDMAN. M. 1966. Canad. J. Genet. Cytol. 8: 144-151. LILIENFELD F. & H. KIHARA 1934. Cytologia 6: 87-122. RILEY R., J. UNRAU & V. CHAPMAN 1958. J. Heredity 49: 90-98. SACHS, L. 1953. Heredity 7: 49-58. SEARS, E.R. 1956. Handbuch der Pflanzenzuchtung, Paul Parey, Berlin und Hamburg, 2nd ed., 2: 164-187. SEARS, E. R. 1976. Ann. Rev. Genet. 10: 31-51. SEARS, E.R. 1980. In 'Wheat science today and tomorrow", Cambridge Univ. Press : 75-89. SHNAIDER, T. & O. PRIILINN 1984, WlS No. 59 : 6-8. WAGENAAR, E. B. 1961. Canad. J. Genet. Cytol. 3: 47-60. WAGENAAR, E. B. 1963. Cereal news 8: 16-19. WAGENAAR, E. B. 1966. Evolution 20: 150-164. ZHUKOVSKI, P.M. 1928. Bull. of Appl. Bot., Genet. and Plant-breeding 19: 59-66. |
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