A GUIDE TO SPORE GROWING
Prepared by the SPORE STUDY GROUP
of the
Fern Society of South Australia Inc
and the Australian National Botanic Gardens
Growing from spore can be a rewarding exercise. With a few easily followed procedures, but firstly it would be of an advantage to know the basic identification of the various stages of
spore reproduction.
Spore is usually found on the backs of fronds. It is housed in a casing called a sporangia, these cluster together to form a sorus, which in some ferns, are covered by a membranous cap called an indusium.
When collecting spore,
it is most important to know and be able to judge when the spore is ripe. The sorus can be observed in three stages of ripeness.
When the
spore is a pale green, the spore is immature, but will slowly ripen until it reaches a stage or appearance to be of a darkish brown to black colour, both swollen and shiny, this is the time to collect the spore.
As the sporangia burst, it will release the ripened spore, leaving behind a sorus that takes on a tatty and furry appearance, often tannish in colour. So remember,
pale green is immature, dark swollen and shiny, is ripe, tatty and tannish in colour, it has gone.
Not all sporangia shed spore that is dark, some is yellowish, some is dark green, it depends on the species.
The spore can be collected by taking a frond with ripened spore, laying it on a sheet of paper, with the sori facing down, cover with
another sheet of paper and keep it in a warm and dry place. The frond will shed the spore, this being a
very fine powder.
Alternatively, the frond can be placed in an envelope, kept in a warm place, with the same result.
After the spore has been shed, there will be empty spore cases mixed with the spore. These need to he separated, which can be done by folding the paper and gently tapping the paper, these spore cases will disperse
because they are light, leaving the heavier spore behind. Also the spore can be sieved as an alternative.
Having collected the spore, the next step is the sowing
of the spore; a container must be chosen, probably the easiest is a plastic container that can be covered so as to retain moisture, i.e. a margarine container proves to be quite adequate, these should be sterilized and kept covered until ready for the sowing.
There is probably no best medium in which to sow spore;
it will eventually be a personal choice of which you think to be the best. We find that the easiest to obtain would be Tree fern fibre sieved, or peat. These are mixed with washed river sand at the rate of two parts sand, to either one of your choice.
The sowing mixture must be sterilized, attainable by placing
it in a dish or an oven bag and kept in an oven at approximately 120° Celsius for approximately 90 minutes.
Allow the mixture to cool, then partially fill the
plastic container with the mixture (about 2-3mm deep), moisten with sterilized water, cover or seal until you are ready to sow the spore.
When you are ready to sow
the spore, remove the cover and spread the spore very thinly and evenly to cover the medium surface;
the slightest amount of breeze will minimise the process as spore will be blown
around everywhere.
The
spreading of the spore can be achieved by covering the tip of a knife with
the spore and by gently tapping the knife edge, the spore can be released on to the surface, once sown, cover and seal immediately.
Gladwrap is ideal for sealing the container,
secured with rubber bands. Label the container, place in a warm, well lit position but not
in direct sunlight.
The next step is
PATIENCE
and plenty of it; this is because
the spore will take its own time to germinate depending on the species, how fresh the spore is and also the conditions. One must remember to check the moisture content in the container periodically, to ensure that the medium does not become dry.
After a period of time,
you should be able to determine if the spore has germinated, by a greening of the surface of the
sowing medium, then, through a process, a tiny heart shaped prothallus will develop. Once the prothallus has been fertilized through a sexual process, a sporophyte or young fernlet will appear at the notch of the prothallus and steadily develop.
When the fernlet has developed new fronds, the prothallus will die and the fernlet will become independent and self supporting.
The fern will continue to develop and after a period of time
it can be pricked out into tubes. Remembering that these must be kept in the same humid conditions that they enjoyed as sporelings.
After further development, the sporelings can be hardened off, transplanted into larger pots and grown to maturity.
The growing from spore is rewarding; you must remember, however, that, depending on the species will determine the time that
you must wait. It is certainly worth a try and it is not that difficult.
TEN COMMANDMENTS FOR GROWING SPORE
1. Thou shalt only sow ripe spores.
2. Thou shalt sterilize the house of spores.
3. Thou shalt plant spores in sterile soil.
4. Thou shalt moisten spores only with sterile water.
5. Thou shalt grow spores in a house of high humidity.
6. Thou shalt keep the house of spores neither too hot
nor too cold.
7. Thou shalt give spores the light but not the heat of the sun.
8. Thou shalt patiently wait the greening of the sporelings.
9. Thou shalt treat fernlets with tender loving care.
10. That shalt smite their foes so that the fernlets may beget more spores.