Without resorting to any further mudslinging...
If you guys are interested in learning. ALL orchid seeds generally consist of 3 basic structures.
1. The outer coat - called the testa. Under the microscope with low powered magnification, they generally look papery and are mostly transparent or translucent. They are also usually 1 cell layer thick. The diagrams posted above by Grautier show the many forms of testa that can present in different species of orchids.
2. The embryo. These can be shaped differently depending on the orchid. Most are spherical. Some are oblong elliptical.
3. The carapace: This is a structure that does not show up in the diagrams that was posted above. It is also usually 1 cell layer thick and envelops the embryo. It is not visible under low powered magnification.
Note: Most orchid seeds do not contain endosperm. Endosperm is like egg yolk to an embryonic plant.
Lack of endosperm in the seed is why the large majority of orchid seeds cannot germinate on their own without the use of symbiotic or asymbiotic in-vitro germination methods (aka tissue culture methods).
Those species that have some stores of endosperm in their seeds are species such as Bletilla striata. I have germinated these seeds without using in-vitro methods and it is the most fun experience ever! Growing the protocorms out was a disaster though...
Although, very few orchids have endosperm, for best seed germination success, it is much safer to assume that there is not a single orchid that has seeds that contain endosperm and just use tissue culture methods to germinate all of them.
In most cases, scarification of the testa is not necessary to germinate seeds. I've only seen mention of this method with orchids such as Cypripediums. For orchids like Phalaenopsis or Cattleya, I've not seen it mentioned as a necessary step for germination.
There are 2 ways to germinate seed:
1. Dry seed.
2. Green seed.
Many people who sow orchid seeds prefer the green seed method where they have the grower collect what is known as mature green pods.
If the seeds are viable, (seed viability depends on whether the embryo is still alive upon sowing), it doesn't really matter if the seeds provided are dry or green.
__________________
Philip
Last edited by King_of_orchid_growing:); 01-21-2022 at 10:53 AM..
|