Orchid Breeding and Hybridizing

Propagation is a science that allows us to replicate orchids by sexual or asexual methods. The millions of small Phalaenopsis orchids that appear in nearly all big box stores today are propagated by mericloning. 

Hybridization is an art that allows us to create new orchids by sexual propagation. Hybridizers pick species or genera by the specific traits they are trying to accentuate, such as color, lip or petal shape, patterns, size, or scent. Hybridizing orchids is a labor of love that requires intuition and a lot of patience.

“One of the by-products of aging is retrospect. To the mature orchid hybridizer, the consideration of past events is not only pleasurable but also valuable as one plans new directions in breeding. One of the keys to making quality hybrids is the knowledge gained from successful parent clones to breeding lines.… Observation and remembrance are the keys to the successful hybridizing of complex hybrids….as a hybridizer, the flowers should speak to you…” - Frank Fordyce

This section will briefly describe the techniques used in propagation and hybridization of orchids, as well as give insight from orchid hybridizers. For more information on the topic of hybridization, see the Orchids Supplement, “Hybridizers”, October 2022.

Propagation

Orchid propagation can occur by asexual or sexual methods. Let’s talk about asexual methods first. Sexual propagation and line breeding will be discussed with hybridization later on.

Asexual Propagation – Vegetative Propagation

Vegetative propagation is a type of asexual propagation meaning there is only one parent plant, so the progenies are identical to the parent. The easiest methods of vegetative propagation are dividing a sympodial orchid or cultivating back bulbs. As described in the Orchids magazine article, “A Beginners Guide to Vegetative Propagation in Orchids”, May 2019, “The two main reasons for dividing an orchid are to propagate the cultivar or because the plant has grown too large. Dividing an orchid will stress the plant as it will lose some of its storage capacity. Never divide a small plant. The plant should have at least eight healthy pseudobulbs before dividing, so that four or five pseudobulbs can be kept with each division, with three as a minimum.”

Also described in this article is the process of backbulb cultivation, which can be used in genera such as Cymbidium orchids. Backbulbs are living (not dried up) pseudobulbs that have lost their leaves. Dormant nodes, or “eyes,” can be encouraged to grow by cutting the backbulb off the parent plant and growing it in sphagnum moss or other suitable potting medium until new roots and leaves appear. Most cymbidium backbulbs are started in flats of the same potting mix used for the adult plants.

Another method of vegetative propagation is when an orchid produces a “keiki” or baby plant. Keikis can occur in monopodial or sympodial orchids and can grow along the main stem or from a node on the inflorescence, depending on the genus. Some species of orchids are very prolific producers of keikis without any encouragement. Others need a little help from products such as Keiki Power Pro, a combination of plant hormones that can encourage a keiki to develop from an unused node. Once the keiki has 2 or 3 leaves and its roots are 1 to 2 inches (2.5-5 cm) long, the keiki can be removed from the parent plant and potted separately. The keiki will need to be watered more frequently than the parent until it develops more roots. 

Asexual Propagation – Meristem Cloning

Meristem cloning is another type of asexual propagation. As with vegetative propagation, the progenies will be identical to the parent. The main difference between these two types of asexual propagation is that vegetative propagation occurs on the plant while cloning occurs in a laboratory.

Cloning has been around for over 60 years. An article published in Orchids in September of 2021, “New Developments in Orchid Cloning”, states “The process of creating exact duplicates began in 1960, with a clever laboratory technique developed by Dr. G.S. Morel. Soon after, the French firm Vacherot & Lecoufle pioneered the procedure on a grand scale and mass-distributed clones worldwide.”

Very simply put, meristem cloning is the process of extracting a small sample, 1 mm or less, of apical meristem from the mother plant. Meristem in a plant are cells that can differentiate into different types of cells, similar to stem cells in humans. Apical meristem cells come from root tips, leaf tips, or new shoot tips. Under sterile conditions, these cells are grown on agar in flasks, repeatedly divided, and eventually allowed to grow into thousands of tiny plantlets. When large enough, these plantlets are removed from the flask (deflasked) and potted.

Hybridization and Line Breeding

Hybridization and line breeding are both forms of sexual propagation resulting from completely different motivations. The desired outcome of line breeding is to improve the plants in a certain orchid line. This is done through self-pollination or, preferably, pollination of siblings and selecting improvements over the parent plant(s).

The desired outcome of hybridization is an entirely new orchid hybrid. This is done with meticulous research, intuition born from years of work, and cross-pollination of two orchids. Hybridization results in progenies that are different from the parent plants. Orchid hybridization was once dominated by large orchid growers, mainly because of the need for sterile laboratories to germinate the seeds and flask the tiny plants. Today, however, with the creation of at-home kits, hobbyist orchid hybridizers are becoming more prevalent. 

Orchid hybridizers need a wealth of patience and space to raise their seedlings. Recognize that an orchid seed capsule can contain millions of tiny naked seeds. Even if only a small percentage of these germinate and grow to seedling size, the numbers can be in the thousands. Then, the hybridizer won’t know if the desired bloom shape or color is present until the seedling matures into blooming size, which can take from 3 to 7 or more years. Finally, since these seedlings are created from a cross-pollination of two different orchids, genetics states that each of the seedlings will be different so the hybridizer wants to raise as many of the seedlings as possible to find his intended outcome. If that desired orchid is not found, the whole process starts over.

The process for line breeding is the same as hybridization, except that the capsule produced may be the result of a selfpollination or two of the same plant (for instance two cultavars of the same species). The intent here is to improve the quality of plants in a specific line. While it still takes several years for the orchids to reach maturity, the outcome is predictable.

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