Pure Line


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Pure Line

 

the homogenous generations of repeatedly self-pollinating plants or self-fertilizing animals, in which most genes are homozygous. The term was introduced in 1903 by the Danish geneticist W. Johannsen, who proved by experimentation on legumes that pure lines exhibit analogous phenotypes under identical conditions.

Pure lines are obtained from a single ancestor and are maintained by self-pollinization and selection. Individuals in pure lines repeat over several generations the same genetically fixed traits. Pure lines are important in agriculture inasmuch as they are the main structural elements of plant varieties. Hybridization of two pure lines often results in heterosis in the first hybrid generation; certain hybrid varieties of corn are obtained in this way.

The term “pure line” is sometimes incorrectly applied to inbred lines, which are the progeny of animals or cross-pollinated plants obtained from a single pair of ancestors and maintained over a number of generations by constant crossing of related individuals and by selection. Such lines are almost always used in genetic research on higher organisms. For example, “pure line” laboratory mice are used to study carcinogenesis and cancer treatment.

I. I. TOLSTORUKOV

References in periodicals archive ?
The Fourier transform of the composite vibration is also a one-sided pure line spectrum.
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Indeed, thinking that pure line can be allegorical radically expands the field of application for this rhetorical figure, restoring metaphorical dignity to abstraction--an element it previously possessed, but which recently seems to have been forgotten.
It is a primordial, aboriginal dance, which Schert laces with a hypnotic elegance of form, a pure line that brings order to chaos, reminding us of the nobility of movement in animals and humans alike.
Top chefs agree that the quality of the rice you use is critical to the overall quality of your meal, and it appears there is no better rice in the world than Pure Line Basmati.
Nor does he judge these bureaucrats and others from some ideologically pure line that he wishes to promote; rather, he subjects them to a no-nonsense, carefully documented exploration of how radical schemes helped destroy individuals and neighborhoods.
She couldn't stand a dirty step, and she loved a pure line.
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He gave value to pure line, and he was so musical I felt he could relate to ballet dancers.