germ plasmとは 意味・読み方・使い方

語源

Calque of German Keimplasma. From circa 1892.

名詞

germ plasm (uncountable)

1. (biology, dated or historical) The cytoplasm of germ cells.
   • 1893, August Weismann, translated by W. Newton Parker and Harriet Rönnfeldt, The Germ-plasm: A Theory of Heredity, Charles Scribner's Sons, page 183:

     If heredity depends on the presence of a substance, the germ-plasm, which causes the production of the new individual by directing the process of division in ontogeny, in the course of which it becomes changed in a regular manner, the question arises as to how unaltered germ-plasm can nevertheless reappear in the germ-cells of the new individual.

   • 1951, Bradley M. Patten, Early Embryology of the Chick, 4th edition, The Blakiston Company, page 10:

     The germ plasm is of paramount interest, not only to the biologist but to all thinking persons, because while the somatic cells cease to exist with the death of the individual whose body they constitute, the germ plasm may live on indefinitely in succeeding generations.

   • 2014, Eva Jablonka, Marion J. Lamb, Evolution in Four Dimensions, The MIT Press (Bradford Books), page 19,

   He^[Weismann] reasoned that since the father's germ plasm in the sperm mixes with the mother's germ plasm in the egg, there are two mingled germ plasms in their offspring.

   Synonym: pole plasm

2. Germplasm; seeds or tissues maintained for the purpose of animal or plant breeding, preservation or other research uses.
   • 1976, Te-Tzu Chang, Manual on Genetic Conservation of Rice Germ Plasm for Evaluation and Utilization, International Rice Research Institute, page 56:

     Although the IRRI has taken on the global responsibility of conserving rice germ plasm, we find it necessary to enlist the collaboration of other international and national organizations in achieving the goals.

使用する際の注意点

• The biology term relates to the obsolete germ plasm theory (Keimplasmatheorie), described in 1892 by German biologist August Weismann. Through his theory he rejected Lamarckism and proposed what came to be called the Weismann barrier: the principle that germ cells can influence somatic cells, but not vice versa. Weismann's theory was made obsolete by genetics, but the idea that changes acquired during an organism's life cannot affect its offspring is still broadly accepted, albeit within a framework of epigenetic variable expression contrasting with mendelian heredity.

Further reading

• germ plasm on Wikipedia.
• Germplasm on Wikipedia.
• Weismann barrier on Wikipedia.

名詞

germplasm (countable かつ uncountable, 複数形 germplasms)

1. Seeds or tissues maintained for the purpose of animal or plant breeding, preservation or other research uses.
   • 1987, Aart van Schoonhove, Standard System for the Evaluation of Bean Germplasm, CIAT, page 5,

     Since the number of problems that affect the bean crop is large, researchers in national and international programs have formed a network on genetic improvement in which germplasm evaluation and research results are exchanged.

   • 1989, Zhang Yihua, Dong Yushen, Development of Research on Crop Germplasm Resources in China, Lloyd Knutson, Allan K. Stoner (editors), Biotic Diversity and Germplasm Preservation, Global Imperatives, Kluwer Academic Publishers, Beltsville Symposia in Agricultural Research 13, page 125,

     A good beginning has been made in joint surveys of Chinese germplasm resources by Chinese and foreign scientists.

   • 2000, R. K. Singh, et al., 9: Small and Medium Grained Aromatic Rices of India, R. K. Singh, U. S. Singh, G. S. Khush (editors), Aromatic Rices, Oxford & IBH Publishing Company, page 170,

     Safeguarding our precious indigenous scented rice germplasms is important for the future.

   • 2002, Barbara M. Reed, I.2: Implementing Cryopreservation for Long-Term Germplasm Preservation in Vegetatively Propagated Species, L. E. Towill, Y. P. S. Bajaj (editors), Cryopreservation of Plant Germplasm II, Springer, Biotechnology in Agriculture and Forestry 50, page 22,

     Cryopreservation is the preferred option for the long-term storage of clonal germplasm (Engelmann 2000).

使用する際の注意点

• A distinction in usage exists between the terms germplasm and germ plasm: the latter seems chiefly to be reserved for a now obsolete concept in biology.

Further reading

• Animal genetic resources for food and agriculture on Wikipedia.
• Cryoconservation of animal genetic resources on Wikipedia.
• Forest genetic resources on Wikipedia.
• Plant genetic resources on Wikipedia.
• Seed saving on Wikipedia.
• Convention on Biological Diversity on Wikipedia.
• International Treaty on Plant Genetic Resources for Food and Agriculture on Wikipedia.