Nom du corpus

Corpus Systématique Végétale

Titre du document

Hybridisation in a wild population of eleocharis palustris

Lien vers le document
Éditeur
Springer (journals)
Langue(s) du document
Anglais
Type de document
Research-article
Nom du fichier dans la ressource
Syst_veg6_v2_025273
Auteur(s)
  • K. R. Lewis 1,2
  • B. John 1,2
Affiliation(s)
  • 1) Botany Department, The University of Oxford, UK
  • 2) Genetics Department, The University of Birmingham, UK
Résumé

1. Twenty-nine inflorescences from plants of Eleocharis palustris in a small area of Port Meadow, Oxford, were found to include four types. Two of these were the recognised sub-species E. p. vulgaris (2n=38) and E. p. microcarpa (2n=16). 2. The former was represented by seven inflorescences one of which was abnormal showing delayed or non-disjunction of the chromosomes at PGM I in approximately 8% of the cells. 3. The latter was represented by ten inflorescence two of which were abnormal showing a failure in 40% of the cells of the nuclear differentiation which normally precedes PGM. 4. In four of the other inflorescences the chromosome number at PGM I ranged from 11 to 18 with a modal value of 14. Plants with 2n=27 chromosomes in the root tips have also been found. We consider these to be F1 hybrids between the two subspecies. 5. In the remaining seven inflorescences, the chromosome number at PGM I ranged from 16 to 21 with a modal value of 18/19. These may be plants of E. p. vulgaris with an abnormal meiosis or hybrid derivatives. 6. The survival of the hybrid material in this population is attributed to the fact that sexual fertility is not at a premium. The meadow has been subjected to continuous grazing for centuries and under these curcumstances survival depends on vegetative vigour and propagation. Presumably the presence of fertility-affecting abnormalities in the parental types can be explained on the same basis as indeed, may the occurrence of hybridisation. 7. Numerical chromosome variation in the genus appears to be due to a variety of causes. a) Aneuploidy. α) Non-disjunction at meiosis (especially in hybrids or hybrid derivatives) or at pollen grain mitosis. β) Fragmentation, perhaps following inversion loop crossing over in structural hybrids—a source of variation which is excluded in most groups by the localisation of centromeres. b) Polyploidy. α) Restitution at meiosis (diploid self-fertilisation). β) Restitution at pollen grain mitosis (formation of homozygous diploid gametes).

Catégories Science-Metrix
  • 1 - health sciences
  • 2 - biomedical research
  • 3 - developmental biology
Catégories INIST
  • 1 - sciences appliquees, technologies et medecines
  • 2 - sciences biologiques et medicales
  • 3 - sciences biologiques fondamentales et appliquees. psychologie
Catégories Scopus
  • 1 - Health Sciences ; 2 - Medicine ; 3 - Genetics(clinical)
  • 1 - Life Sciences ; 2 - Biochemistry, Genetics and Molecular Biology ; 3 - Genetics
Catégories WoS
  • 1 - science ; 2 - genetics & heredity
  • 1 - science ; 2 - biochemistry & molecular biology
Identifiant ISTEX
4BBFB78882762F36516318C3EC66361103AC6B6D
Revue

Chromosoma

Année de publication
1961
Présence de XML structuré
Non
Score qualité du texte
10
Version PDF
1.3
Type de publication
Journal
ark:/67375/1BB-06DGTLMB-0
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