Nom du corpus

Corpus Systématique Végétale

Titre du document

Maximisation of reproductive success by European orchidaceae under conditions of infrequent pollination

Lien vers le document
Éditeur
Springer (journals)
Langue(s) du document
Anglais
Type de document
Research-article
Mots-clés d'auteur
  • Orchid pollinia
  • Pollination limitation
  • Reproductive maximisation
  • Post-pollination events
  • Pollen longevity
  • Pollen loads
  • P ∶ O : pollen ∶ ovule ratio
  • PL ∶ O : pollen-load ∶ ovule ratio
  • FCR : fluorochromatic reaction test
Nom du fichier dans la ressource
Syst_veg6_v2_019480
Auteur(s)
  • M. R. M. Neiland 1
  • C. C. Wilcock 1
Affiliation(s)
  • 1) Department of Plant and Soil Science, University of Aberdeen, Cruickshank Building, St. Machar Drive, AB9 2UD, Aberdeen, Scotland, UK
Résumé

The pollination biology of a group of European orchids (Dactylorhiza, Ophrys, Orchis, Platanthera, Goodyera, andSerapias species) are investigated, and their anthecological characteristics considered in relation to natural levels of reproductive success. Pollen ∶ ovule (P ∶ O) ratios of the European orchids surveyed range from 10 ∶ 1 (Goodyera repens) to 24 ∶ 1 (Platanthera chlorantha). Average pollen-load ∶ ovule ratios are consistently lower than P ∶ O ratios. Naturally occurring pollen loads range from 1 massula to >1 pollinium. Even the smallest pollen load is sufficient to stimulate embryogenesis in experimentally pollinatedDactylorhiza purpurella flowers, although more seeds are set with larger loads. Pollen tubes grow rapidly through the stylar canal and into the top of the ovary within 2 or 3 days of pollination, and grow down either side of the 3 parietal ridges in the ovary. Fertilisation occurs throughout the length of the ovary but its distribution is non-random, especially when pollen loads are limiting, with more seeds being set at the stylar end. All species ofDactylorhiza, Ophrys, andOrchis studied are highly self-compatible. In the absence of pollination,Ophrys andOrchis flowers remain open and fertile for at least 3 weeks. Pollinated flowers remain receptive to further pollinations for at least 8 days. Some fruits can even be obtained on selfing 20-day-old unpollinatedOrchis morio flowers. Excised pollinia retain germinability for a long time, up to 51 days inDactylorhiza purpurella. The arrival of pollen on the stigma hastens floral senescence, but post-pollination changes are relatively slow when compared with those reported for tropical orchid species. It is concluded that characteristics of the pollination biology of European orchids act to maximise reproductive success by (1) prolonging the opportunity for effective pollen deposition both pre- and post-pollination, (2) increasing the likelihood of widespread dispersal, (3) reducing pollen wastage, and (4) increasing seed quality by promoting some pollen competition. As most European orchids are xenogamous and require pollen to arrive on the stigma before seed can be set, reproductive maximisation is of particular adaptive advantage because many of them are infrequently visited by insects so that the probability of successful pollination can be very low.

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
  • 4 - ecologie animale, vegetale et microbienne
Catégories Scopus
  • 1 - Life Sciences ; 2 - Biochemistry, Genetics and Molecular Biology ; 3 - Cell Biology
  • 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Plant Science
  • 1 - Health Sciences ; 2 - Medicine ; 3 - General Medicine
Catégories WoS
  • 1 - science ; 2 - plant sciences
  • 1 - science ; 2 - cell biology
Identifiant ISTEX
8883F82D655F95964C19FFE8D91E6EFB4447865F
Revue

Protoplasma

Année de publication
1995
Présence de XML structuré
Non
Score qualité du texte
10
Version PDF
1.3
Type de publication
Journal
ark:/67375/1BB-0BMZV6H0-D
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