Biotype

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biotype

[′bī·ə‚tīp]
(genetics)
A group of organisms having the same genotype.

Biotype

 

a group of organisms, part of a local population, which have the same genotype and are similar in practically all respects. The Danish biologist W. Johannsen (1909) considered the homozygotic biotype in self-pollinating plants to be the most elementary structural unit of a population. The Soviet botanist V. N. Sukachev (1927, 1935) called clones of plants that were derived by numerous root grafts of the plant or by division of a single bush “biotypes.” In populations of cross-pollinated species, biotypes can be distinguished both as successive selection with isolation of the offspring and as manyfold multiplication in close degrees of relation (inbreeding). In the 1920’s and 1930’s many biologists (the Swedish botanist G. Turesson; the Soviet biologists N. I. Vavilov, M. A. Rozanova, and others) considered biotypes to be the smallest taxonomical unit. Species, in their opinion, arose from combination of biotypes as a result of recombination and selection.

Large groups of organisms, often consisting of many species and characterized by similar adaptation to the exploitation of definite habitation conditions, are also called biological types or life forms. In this sense, for example, the group of underground burrowing rodents, the group of ephemeral desert plants, and so on are taken to be biological types.

REFERENCES

Berman, Z. I., K. M. Zavadskii, A. L. Zelikman, et al. Sovremennye problemy evoliutsionnoi teorii. Leningrad, 1967.
Zavadskii, K. M. Vid i vidoobrazovanie. Leningrad, 1968.

K. M. ZAVADSKII

References in periodicals archive ?
Subsequent surveys have turned up additional evidence of new biotypes, an evolving threat.
Conventional biotyping methods and a combination of MAMA-and conventional- PCRs were used for classifying the strains into prototype El Tor, hybrid, or El Tor variant biotypes, based on their ctxB and rstR genes (21-23).
Occurrence of three genotypic clusters of Bemisia tabaci and the rapid spread of the B biotype in south India.
cholerae O1 El Tor biotype (22 from flood-affected and 16 from non-flood-affected regions) were isolated and mapped to locations across Pakistan (Figure 1).
Resistance to biotype 2 Russian wheat aphid (Homoptera: Aphididae) in two wheat lines.
Instead of performing a mutation study based mainly on comparative genetic analysis (15,22-24), we focus on S1/S2, a functionally relevant site, and study variations between the biotypes and their functional effects.
cholerae O1 belongs to two biotypes, namely classical and El Tor which differ in certain phenotypic and genetic characteristics (4,5).
cholerae O1 is categorized as classical and El Tor biotypes, which differ biochemically and have different levels of virulence.
Leading edge research even includes mapping the genetic codes of weed biotypes to better understand and respond to evolved resistance.