Comparative in vitro germination ecology of Calopogon tuberosus var. tuberosus (Orchidaceae) across its geographic range

Seed responses to temperature are often essential to the study of germination ecology, but the ecological role of temperature in orchid seed germination remains uncertain. The response of orchid seeds to cold stratification have been studied, but the exact physiological role remains unclear. No stud...

Full description

Saved in:
Bibliographic Details
Published in:In vitro cellular & developmental biology. Plant 2011-02, Vol.47 (1), p.148-156
Main Authors: Kauth, Philip J, Kane, Michael E, Vendrame, Wagner A
Format: Article
Language:English
Subjects:
Biomedical and Life Sciences
Cell Biology
Chills
Cold
Cooling
Developmental Biology
Dormancy
Ecology
Embryos
Germination
High temperature
INVITED REVIEW
Life Sciences
Physiology
Plant Breeding/Biotechnology
Plant Genetics and Genomics
Plant Sciences
Population ecology
Seed germination
Seedlings
Seeds
Stratification
Studies
Temperature effects
Wildlife sanctuaries
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Seed responses to temperature are often essential to the study of germination ecology, but the ecological role of temperature in orchid seed germination remains uncertain. The response of orchid seeds to cold stratification have been studied, but the exact physiological role remains unclear. No studies exist that compare the effects of either cold stratification or temperature on germination among distant populations of the same species. In two separate experiments, the role of temperature (25, 22/11, 27/15, 29/19, 33/24°C) and chilling at 10°C on in vitro seed germination were investigated using distant populations of Calopogon tuberosus var. tuberosus. Cooler temperatures promoted germination of Michigan seeds; warmer temperatures promoted germination of South Carolina and north central Florida seeds. South Florida seed germination was highest under both warm and cool temperatures. More advanced seedling development generally occurred at higher temperatures with the exception of south Florida seedlings, in which the warmest temperature suppressed development. Fluctuating diurnal temperatures were more beneficial for germination compared to constant temperatures. Cold stratification had a positive effect on germination among all populations, but South Carolina seeds required the longest chilling treatments to obtain maximum germination. Results from the cold stratification experiment indicate that a physiological dormancy is present, but the degree of dormancy varies across the species range. The variable responses among populations may indicate ecotypic differentiation.
ISSN:1054-5476
1475-2689
DOI:10.1007/s11627-010-9316-5