Generative reproduction

Generative reproduction

Growing orchids from seeds is subject to special conditions and is extremely complicated to work with. Only a few orchid friends therefore concern themselves with it. Nevertheless, the basics and the method should be described in the simplest possible way. It is undoubtedly the most interesting work on orchids. Nothing else is so directly related to their development. Due to the peculiarity of the sowing, all stages of germination are available for them, which take place in other plants in the dark of the earth, directly to the eye. The further development also gives rise to a much closer bond compared to other plants. It doesn't seem excessive, when the cultivation from seeds is called the culmination of all efforts for orchids. Success is not easy to achieve. You need an above-average degree of empathy, Patience and perseverance for this and also the ability, To accept failures, without losing heart.

Orchids live in association with microscopic root fungi. They are found in the outward ones, so-called fungal host cells of the root tips and are thus protected against the dangers of the environment. This dependency, known as symbiosis, of two completely opposite forms of plant life only exists to a small extent elsewhere within the plant kingdom. Orchid seeds have no nutrient tissue whatsoever, which usually enables the first nourishment of the germinating embryo. This function is performed by the root fungi in orchids. Their hyphae grow into the moisture-swollen seeds through special inlet cells. They mediate the uptake of organic substances, that they are "digested" in the embryo cells. This process continues later as a constant interaction with the fungal hyphae which have accumulated in dense clusters in the inner root cells. Only in the outer cells of the root cortex do they remain protected and functional.

The interrelationships between orchids and root fungi were explored by the French researcher Noel Bernard at the beginning of this century; in year 1904 he published his findings. Two directions in sowing methods developed from this. The first assumed the presence of the root fungus as a determining factor for germination. The root fungus was isolated from the growth zone of the roots and cultivated in pure cultures. Suitable culture media were inoculated with it and, after the hyphae had developed, seeds were added. This method is extremely time-consuming and is rarely used. The asymbiotic method is commonly used. The necessary nutrients are added to the nutrient medium, replaces the function of the root fungi by adding certain types of sugar. Of particular importance is the complete sterility of both the nutrient medium and the seed.

There are variations in the composition of the nutrient medium. The listed classic recipes by Burgeff and Knudson are still valid today. There are insignificant modifications, which often correspond to the individual opinion of the respective breeder. Additions of vitamins and growth substances are possible, complicate the way of working and should not be discussed here. The simplest form is shown. It allows you to work without a laboratory, whose presence in and of itself is a condition.

Leave a Reply

Your email address will not be published. Required fields are marked *