Articles
IN VITRO PROPAGATION AND ANATOMICAL STUDIES OF TEMPERATE ORCHID SPECIES (ORCHIDACEAE)
Article number
520_6
Pages
75 – 82
Language
Abstract
A worldwide growing interest in nature conservation requires a concerted effort to protect plant species close to extinction.
Orchid seeds are tiny and have rudimentary embryos, so propagation from seeds poses specific problems.
Seeds of 52 different species of temperate terrestrial orchids were disinfested and sown on a modified Fast medium.
After sowing, the cultures were kept in the dark at 10–12°C for four weeks.
Then the temperature was raised to 25–26°C until germination occurred.
Thereafter, cultures required alternating seasonal temperatures: 25–26°C from the beginning of April to the end of September and 17–19°C from October through March.
Growth stages, including the date of seed and embryo imbibing, opening of the seed coat and earliest protocorm stage, were compared among the different species.
For the development of the young plantlets, natural dispersed light and prevailing day-length were favorable.
Twenty-five different orchid species were successfully grown with this method and after two to three years of aseptic culture they were suitable for transfer ex vitro.
Plant material samples from several different temperate orchid species were also observed by scanning electron microscopy.
The first visible step of germination was the opening of the seed coat and the apical meristem appeared a few weeks later.
The young protocorm was covered with numerous translucent rhizoids.
In the last stage of germination, the first true leaf and the first root started to develop.
Structure of the mature organs and tissues was also examined.
New information was found about the structural details of roots with orchid-type mycorrhiza and stored materials (calcium oxalate crystals and starch), leaf/stem stomatal structure and anatomical details of the generative organs and ovule/seed development.
Orchid seeds are tiny and have rudimentary embryos, so propagation from seeds poses specific problems.
Seeds of 52 different species of temperate terrestrial orchids were disinfested and sown on a modified Fast medium.
After sowing, the cultures were kept in the dark at 10–12°C for four weeks.
Then the temperature was raised to 25–26°C until germination occurred.
Thereafter, cultures required alternating seasonal temperatures: 25–26°C from the beginning of April to the end of September and 17–19°C from October through March.
Growth stages, including the date of seed and embryo imbibing, opening of the seed coat and earliest protocorm stage, were compared among the different species.
For the development of the young plantlets, natural dispersed light and prevailing day-length were favorable.
Twenty-five different orchid species were successfully grown with this method and after two to three years of aseptic culture they were suitable for transfer ex vitro.
Plant material samples from several different temperate orchid species were also observed by scanning electron microscopy.
The first visible step of germination was the opening of the seed coat and the apical meristem appeared a few weeks later.
The young protocorm was covered with numerous translucent rhizoids.
In the last stage of germination, the first true leaf and the first root started to develop.
Structure of the mature organs and tissues was also examined.
New information was found about the structural details of roots with orchid-type mycorrhiza and stored materials (calcium oxalate crystals and starch), leaf/stem stomatal structure and anatomical details of the generative organs and ovule/seed development.
Authors
E. Szendrak, P.E. Read
Keywords
in vitro germination, in vitro propagation, scanning electron microscopy, temperate orchids
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