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The origin and meiotic behaviour of hexaploid northern wheatgrass (Agropyron dasystachyum)

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Abstract

The occurrence of hexaploid (2n = 6x = 42) forms in some otherwise natural tetraploid populations of Agropyron dasystachyum (2n = 4x = 28) was cytologically detected and studied. The hexaploid plants are morphologically similar to the tetraploids except for a small reduction in the anther size. The general survey of chromosome numbers of natural Northern Wheatgrass (A. dasystachyum 2n = 4x = 28) populations derived from eight different regions of Alberta indicated that the occurrence of hexaploid variants was not restricted to a single locality. A comparative study of chromosome pairing in the natural and the synthetic hexaploids revealed that the naturally occurring 42-chromosomed plants of A. dasystachyum originated as a result of fertilization between unreduced (SSHH) and the natural (SH) gametes, both coming from the tetraploid form of A. dasystachyum. Based on chromosome pairing, the genomes of the natural hexaploid A. dasystachyum have been designated as SSSHHH. The natural hexaploids appear to intercross among themselves and also with tetraploids producing euploid and aneuploid hybrids. The possible evolutionary significance of these findings is briefly discussed.

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References

  1. Bowden, W.M.: Cytotaxonomy of the species and interspecific hybrids of the genus Agropyron in Canada and neighboring areas. Canad. J. Bot. 43, 1421–1448 (1965)

  2. Dewey, D.R.: Morphology, cytology and fertility of synthetic hybrids of Agropryon spicatum x A. dasystachyum-riparium. Bot. Gaz. 126, 269–275 (1965)

  3. Dewey, D.R.: Cytogenetics of Agropyron pringlei and its hybrids with A. spicatum, A. seribneri, A. vidaceum, and A. dasystachyum. Bot. Gaz. 137, 179–185 (1976)

  4. Grant, V.: Cytogenetics of the hybrid Gilia millefoliata x achilleaefolia. I. Variations in meiosis and polyploidy rate as affected by nutritional and genetic conditions. Chromosoma (Berl.) 5, 372–390 (1952)

  5. Harlan, J.R., DeWet, J.M.J.: On Ö. Winge and a prayer: The origins of polyploidy. Bot. Rev. 41, 361–390 (1975)

  6. Islam, A.K.M.R., Shepherd, K.W.: Meiotic restitution in wheat-barley hybrids. Chromosoma (Berl.) 79, 363–372 (1980)

  7. Sadasivaiah, R.S., Rajhathy, T.: Genome relationships in tetraploid Avena. Canad. J. Genet. Cytol. 10, 655–669 (1968)

  8. Skiebe, K.: Die Entstehung von polyploiden Populationen in der Evolution. Deutsch. Landw. (Berl.) 16, 340–343 (1965)

  9. Stebbins, G.L.: Variation and evolution in plants, pp. 643. New York; Columbia Univ. Press 1950

  10. Stebbins, Jr., G.L.: Chromosomal evolution in higher plants, pp. 216. Menlo Park (California): Addison-Wesley Publ Co. 1970

  11. Stebbins, Jr., G.L., Snyder, L.A.: Artificial and natural hybrids in the Gramineae, tribe Hordeae. XI Hybrids between western and eastern North American species. Amer. J. Bot. 43, 305–312 (1956)

  12. Sved, J.A.: Telomere attachment of chromosomes. Some genetical and cytological consequences. Genetics 53, 747–756 (1966)

  13. Wagenaar, E.B.: Meiotic restitution and the origin of polyploidy. I. Influence of genotype on polyploid seed set in a Triticum crassum x T. turgidum hybrid. Canad. J. Genet. Cytol. 10, 836–843 (1968)

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Sadasivaiah, R.S., Weijer, J. The origin and meiotic behaviour of hexaploid northern wheatgrass (Agropyron dasystachyum). Chromosoma 82, 121–132 (1981). https://doi.org/10.1007/BF00285755

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Keywords

  • Developmental Biology
  • Chromosome Number
  • Single Locality
  • Chromosome Pairing
  • Small Reduction