Exploring scientific and natural methods of lily breeding
The science behind breeding lilies
In today's world, plant breeding has undergone rapid change. Biological science is beginning to play a powerful role, and the altering and restructuring of DNA is becoming far more common.
From ongoing developments in biotechnology, research is now being applied to the genetic engineering of significant cut flower species in the floriculture industry.
Through genetic modification, it is possible to insert genetic material into plant cells and to then produce new plant forms from these modified cells in sterile tissue culture. By using gene technology, there is the ability to transfer genes from any source in order to achieve increased productivity and novelty in flowers. Mainly based in Japan, the Netherlands, Australia and the USA, major plant research laboratories are developing and applying advanced processes using gene technology to create 'perfect' patented flowers.
Lilies have been bred and rebred into multiple hybrid forms for some time now. Combining
complex genetic knowledge and horticulture experience, parent plants are selected and hybridized, using techniques such as tissue culture, embryo rescue, polyploidization
and in-vitro pollination. To ensure success, detailed planning and chromosomal study across different lily groups are carried out by commercial plant breeders.
With breeding involving extremely time-consuming procedures, billions of dollars are subsequently invested in the genetic modification industry by governments, private investors and multi-national companies, and potential future revenues are a strong
Longiflorum, Asiatic and Oriental hybrids are the most common types utilized in commercial breeding. Significant research is being conducted in the Netherlands in order to develop disease resistance in lilies. Beyond breeding for resistance, other aims include the improvement of flower longevity, bulb growth, and the ability for 'forcing' in Easter Lilies (Lilium longiflorum).
Hybridizing is essentially a human quest for perfection in color, fragrance, versatility and disease resistance in flowers. A rare result in nature, the act of deliberate hybridizing began in the 19th Century, with modern horticultural practices of the 20th Century influencing an unrestrained approach towards creating the 'ideal' lily.
Thousands of hybrid varieties have come into existence since the 1950s, and every year new ones are registered by private plant breeders and commercial enterprises. Much depends on the market potential of new hybrids and the value of patented 'grower friendly' versions.
Most lilies sold today are hybrids and are named in single quotes, eg 'Casa Blanca', 'Star Gazer' or 'Nerone' (which is pictured below). Asiatic, Oriental and LA hybrids share widespread popularity with gardeners and the cut flower industry, equally admired for their upright flowers and exotic color range.
Lilies feature large, accessible flower parts and can easily be cross-pollinated by hand. This is done by transferring pollen between two lilies; from the anther of the pollen parent to the stigma of the seed parent. A commonly used technique, simple crosses can be made either between two species, two hybrids or a species with a hybrid.
While hybridizing does create some spectacular results, there are some downsides. Many of these plants feature long breeding histories that are impossible to link back to the specific species and/or hybrids from which they originated. Far removed from their parent plants, hybrids can only be reproduced vegetatively and cannot be relied upon from seed.
Unfortunately, these processes also increase the likelihood of a 'watering down' effect on the genetic biodiversity of the Lilium genus, and makes it even more vital that species lilies – the basis of all hybrids – have a continued presence in both our gardens and nature itself.
Propagating lilies by natural means
Propagating lilies can be one of the most rewarding experiences in the garden. However, it is worth making sure any plant stock you have is from a reputable source and not collected from lily species (endangered or otherwise) growing in the wild.
The following techniques are easy and simple for any home gardener to use. They can also be a good way of helping the survival of historic Lilium species – particularly when growing rare types that may not be available as bulbs.
Lilies can be propagated by:
- bulblets, and
- bulb division.
Propagating by seed is an ideal way of raising disease-free lilies. There are two types of germination and this varies from one lily species to the next. Epigeal and hypogeal seeds can be quick (immediate) or slow (delayed) to germinate, and the first leaf often appears within a few weeks or months (or years, in some cases!) Seed may be grown in pots of moist seed mix, vermiculite, moss or pumice, in warm or cold conditions as required.
These can be removed from lily bulbs at different times of the year and are a common vegetative means of reproducing parent plants. They should be snapped off near the base of the bulb and placed in a moist gritty medium in a warm place until small bulblets begin to form. These can be separated from the scale or left intact for planting outdoors and will take several years to reach full size.
Bulbils form above ground (pictured above) and are only found in the leaf axils of several lily species, such as the Tiger Lily (Lilium lancifolium). Small and black-brown in appearance, these mini bulbs can be gently removed from the plant and placed in seed beds or pots for planting out at a later stage. By growing bulbils, a large number of one lily type can easily be achieved.
These are small sized bulbs that develop underground just above the main bulb of some lilies. They are best removed during Summer and Autumn months, and potted up for further growth. Additional bulblets can be encouraged by deep planting stem-rooting lilies.
Dividing bulbs is possible with rhizomatous, concentric and stoloniferous types of lily bulbs. This method of propagation is an ideal way of quickly increasing lilies throughout the garden. Lily bulbs can be dug up in Autumn, separated and then immediately replanted into suitable growing areas.