In Vitro Methods for Conservation of Plant Genetic Resources - Couverture rigide

Couverture rigide

ISBN 10 : 041233870X ISBN 13 : 9780412338700

Editeur : Chapman and Hall, 1990

Synopsis

However, the transition from primitive to 'advanced' cultivars has had the effect of narrowing the genetic base. This has happened in two distinct ways: (1) selection for relative uniformity, resulting in 'pure' lines, multi- lines, single or double hybrids, etc.; and (2) selection for closely defined objectives. Both of these processes have resulted in a marked reduction in genetic variation. At the same time, there has been a tendency to restrict the gene pool from which parental material has been drawn. This is a result of the high level of productivity achieved when breeding within a restricted but well-adapted gene pool, and of breeding methods which have made it possible to introduce specifically desired improvements, such as disease resistance and quality characteristics, into breeding stocks with a minimum of disturbance to genotypic structure. Developments in agriculture, such as intensive mechanization, the widespread application of fertilizers and the use of herbicides, fungicides and pesticides, have created a situation whereby a few, selected high- yielding cultivars may be grown over large parts of the earth, so further contributing to a decline in crop genetic diversity. This process is under way in all countries, both developed and developing, and unfortunately in- cludes some of the richest primary and secondary gene centres of several important food crops.

Détails de l'édition

• Éditeur: Chapman and Hall
• Date d'édition: 1990
• Langue: anglais
• ISBN 10: 041233870X
• ISBN 13: 9780412338700
• Reliure: Relié
• Nombre de pages: 255
• Éditeur: Dodds J.H.
• Coordonnées du fabricant: non disponible
• Personne responsable: CMN Printpool Inh. Mathis Neumann; https://www.also.com/ec/cms5/en_6000/6000/index.jsp; ; Friedrich-Karl-Str. 9; Hamburg; Allemagne