| 释义 |
polyploid, a. (n.) Biol.|ˈpɒlɪplɔɪd|
[a. G. polyploid (H. Winkler 1916, in Zeitschr. f. Bot. VIII. 422): see poly- and -ploid.]
Having more than two homologous sets of chromosomes (in each cell nucleus). Also as n., a polyploid organism.
1920W. E. Agar Cytol. vii. 209 In the Protista..it appears that the nucleus may be polyploid, containing, not one or two, but a great number of series of elements. 1924Hereditas V. 168 The chromosome number of a polyploid species must necessarily contain a certain number of complete haploid chromosome sets and it must have arisen through addition of such sets. 1928[see allopolyploidy]. 1936Discovery May 162/1 An account of the breeding behaviour of polyploid plants would be of almost universal interest since this class includes important crops such as wheat, oats, and tobacco. 1949A. G. Sanders in H. W. Florey et al. Antibiotics II. xvi. 683 In the field of agriculture polyploid forms of plants produced by chemical means have been of great importance as they are larger and often more vigorous than the normal plant. 1956[see euploid a.]. 1963E. Mayr Animal Species & Evolution xv. 439 Two types of polyploids are distinguished that have a rather different significance in evolution: autopolyploids and allopolyploids. 1975J. B. Jenkins Genetics iv. 135 Although some animal tissues are commonly polyploid (the liver, for example), polyploid animals are rare. Most animal polyploids reproduce either hermaphroditically..or parthenogenetically.
Hence ˈpolyploidy [cf. G. polyploidie (E. Strasburger 1910, in Flora C. 406)], the condition of being polyploid.
1922Genetics VII. 545 The value of polyploidy may have certain limitations. 1942,1943[see endomitosis s.v. endo-]. 1973Nature 11 May 87/2 Polyploidy may increase the flexibility of a species. |