tetraploidadj.n.

1914 Proc. Royal Soc. 1913–14 B. 87 484 In the tetraploid giants the chromosomes are 2x(24) in the gametic and..4x(48) in the somatic cells.

1921 Amer. Naturalist 55 261 Few-noded tetraploids, however, are less easily distinguished.

1932 F. W. Sansome & J. L. Philp Recent Adv. in Plant Genetics v. 182 There are five possible types of zygote in the tetraploid, quadruplex SSSS, triple SSSs, duplex SSss, simplex Ssss and nulliplex ssss.

1952 New Biol. 13 38 It is necessary, before tetraploid rye can be introduced for general cultivation, to see that no normal rye is grown in the locality where the tetraploid is to be grown.

1974 E. C. Stacey Peace Country Heritage ii. 90 Clover..breeders also have concentrated some of the better features, such as leaf retention and plant vigor, into ‘tetraploids’ by doubling the usual number of chromosomes.

1982 Sci. Amer. May 118/3 Potato plants are tetraploid.

1918 E. B. Babcock & R. E. Clausen Genetics in Relation to Agric. xiv. 263 The doubling of the number of chromosomes typical of the species is known as tetraploidy.

1924 E. W. Macbride Study Heredity (1925) viii. 216 Other examples of such ‘tetraploidy’ (i.e. doubling the ordinary ‘diploid’ number of chromosomes) are known to occur amongst the progeny of hybrids between different species.

1941 Amer. Naturalist 75 321 In many ornamental plants there is a definite need for new types with larger flowers, later blooming habit, and other characteristics usually associated with tetraploidy.

1970 Sci. Jrnl. June 78/3 In lower animal forms both triploidy and tetraploidy are compatible with normal development.