Nos liseuses Vivlio rencontrent actuellement des problèmes de synchronisation. Nous faisons tout notre possible pour résoudre ce problème le plus rapidement possible. Toutes nos excuses pour la gêne occasionnée !
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Nos liseuses Vivlio rencontrent actuellement des problèmes de synchronisation. Nous faisons tout notre possible pour résoudre ce problème le plus rapidement possible. Toutes nos excuses pour la gêne occasionnée !
- Retrait gratuit dans votre magasin Club
- 7.000.0000 titres dans notre catalogue
- Payer en toute sécurité
- Toujours un magasin près de chez vous
Description
The germ plasm of numerous plant species, especially those of forest trees, some agricultural crops, and medicinal plants, is endangered and threatened with extinction. This depletion of germplasm pools and the shrinkage of naturally occurring genetic resources have caused international concern. Conventionally, the germplasm of plants is conserved through seeds, tubers, roots, corms, rhizomes, bulbs, cuttings, etc. However, the germ plasm of a number of trees and plantation crops (such as coconut, cocao, coffee, oil palm, rubber, mango, horse chestnut, etc. ) cannot be preserved since their seed are short-lived (recalcitrant). Likewise, germplasm of vegetatively propagated crops (such as potato and cassava) cannot be stored on a long- term basis and has to be grown and multiplied periodically in nurseries and fields. The plants are thus exposed to unpredictable weather conditions and diseases, with the result that instances are known where entire genetic stocks are lost. Therefore, unconventional methods are being developed for the storage and international exchange of germplasm. For this purpose in vitro cultures have been employed, but they can only enable short-to medium- term preservation; moreover, cell cultures upon repeated subculture undergo genetic erosion. In view of the recent developments in the in vitro induction of genetic variability through somaclonal variation, somatic hybridization, recombinant DNA technology, etc., new methods need to be employed for the storage of desirable cultures. In this regard freeze preservation of cells in liquid nitrogen (-196 0q, like that of semen, enables long-term storage, theoretically, for an indefinite period of time.
Spécifications
Parties prenantes
- Auteur(s) :
- Editeur:
Contenu
- Nombre de pages :
- 514
- Langue:
- Anglais
- Collection :
- Tome:
- n° 32
Caractéristiques
- EAN:
- 9783540574514
- Date de parution :
- 29-09-95
- Format:
- Livre relié
- Format numérique:
- Genaaid
- Dimensions :
- 156 mm x 234 mm
- Poids :
- 925 g
