Nom du corpus

Corpus Systématique Végétale

Titre du document

Reproductive system and pattern of genetic variation in two Limnanthes species

Lien vers le document
Éditeur
Springer (journals)
Langue(s) du document
Anglais
Type de document
Research-article
Mots-clés d'auteur
  • Evolution of inbreeding
  • Electrophoretic variation
  • Phenotypic plasticity
  • Variation patterns
Nom du fichier dans la ressource
Syst_veg6_v2_014120
Auteur(s)
  • C. R. Brown 1
  • S. K. Jain 1
Affiliation(s)
  • 1) Department of Agronomy and Range Science, University of California, Davis, USA
Résumé

Several populations of two species of the genus Limnanthes, (L. alba, an outbreeder and L. floccosa, an inbreeder) were examined with respect to variability of fifteen quantitative characters, allozyme variation at 11 loci, and response to different pollination conditions and moisture stress. Nearly equal amounts of phenotypic variability were found in the two species. L. alba had higher within-family variability than L. floccosa, but this result was highly heterogeneous among characters. A study of between- and within-population variance estimates did not reject the null hypothesis that L. alba and L. floccosa are similar with regard to the partitioning and amount of variability for quantitative characters. However, allozyme variation at 11 loci in a large number of populations showed L. alba to be highly polymorphic in contrast to the virtual monomorphism within L. floccosa populations. The average number of alleles per locus in L. alba and L. floccosa was 1.97 and 1.02, respectively, and on an average, L. alba and L. floccosa populations had 63% and 3% loci with polymorphism, respectively. Three groups of allozyme allelic combinations emerged which correlated well with the taxonomic delineation of allogamous L. alba, three semi-autogamous L. floccosa forms and two autogamous L. floccosa forms. All taxa showed a significant reduction in the seed output per plant due to moisture stress. L. alba suffered a further loss of fecundity under the paucity of pollinators, L. floccosa ssp. floccosa showed no significant effect from this factor, whereas L. floccosa ssp. grandiflora exhibited a curvilinear response which peaked at ‘partial pollination’ and decreased to a lower level at ‘full pollination.’ The geographic distribution of the two species with regard to the temperature and rainfall distribution did not suggest L. floccosa to be living in drier marginal areas. Patterns of variation in flowering time showed L. alba to be less variable than L. floccosa. Overall, there seemed to be little direct support for the thesis that inbreeding species originated from outcrossing taxa in marginal environments as a direct adaptation to a shortened growing season of xeric environments and to the lack of pollinators. Alternative hypotheses suggest that autogamy in L. floccosa might have evolved as a reproductive isolating barrier acting through either cleistogamy or divergence in flowering times.

Catégories Science-Metrix
  • 1 - natural sciences
  • 2 - biology
  • 3 - plant biology & botany
Catégories INIST
  • 1 - sciences appliquees, technologies et medecines
  • 2 - sciences biologiques et medicales
  • 3 - sciences biologiques fondamentales et appliquees. psychologie
Catégories Scopus
  • 1 - Life Sciences ; 2 - Biochemistry, Genetics and Molecular Biology ; 3 - Genetics
  • 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Agronomy and Crop Science
  • 1 - Health Sciences ; 2 - Medicine ; 3 - General Medicine
  • 1 - Life Sciences ; 2 - Biochemistry, Genetics and Molecular Biology ; 3 - Biotechnology
Catégories WoS
  • 1 - science ; 2 - plant sciences
  • 1 - science ; 2 - horticulture
  • 1 - science ; 2 - genetics & heredity
  • 1 - science ; 2 - agronomy
Identifiant ISTEX
3F718500B8DBF67D6F36C517FAC1ED3703F8270B
Revue

Theoretical and Applied Genetics

Année de publication
1979
Présence de XML structuré
Non
Score qualité du texte
10
Version PDF
1.3
Type de publication
Journal
ark:/67375/1BB-0Q3TQLLP-H
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