Why Breed Lilies
There are a number of reasons why one should breed lilies. The primary aim ought to be developing new flowers using new or better colors or color combinations. Some breeders may also be working to develop larger lily blooms or flowers with wider petals. Then gain, the aim could be getting more flowers to a head, or maybe more significantly, a better and enjoyable disposition of the flowers is the top priority for the breeder. On the other hand, professional lily growers would like to put the new plant’s ability to resist diseases as the top priority in their list of reasons. In fact, all lily aficionados should also keep health of the new plants they develop in their mind.
There may be several other reasons for breeding lilies. Some growers may aim to lengthen the flowering period of certain group of lilies. It would certainly be a big bonus to be able to successfully breed lily cultivars that would last for about a week or maybe even longer. Nearly all Asiatic lilies are not aromatic, something that a newcomer to lily breeding would want to change quickly. There are several lily species that are very less fragrant, but this certainly does not nullify the idea that a variety of excellent garden Asiatics having pleasant aromas would be desired by one and all. In fact, commercial lily breeders have already accepted Orientals having little aromas with the view that the blooms with assertive fragrances are not in great demand as those with less perfume.
A number of lilies with short stems are ideal for growing in pots or containers and breeders have already raised them successfully. Nevertheless, still there is a great need for a greater assortment of flower types and colors. Several breeders have an obsession for breeding lilies with flowers fit for the cut-flower business and this has given rise to an overabundance of straight-facing blooms – an absolutely accepted form, but maybe not an appearance that epitomizes the crucial elegance of the genus. Elegant, partially-pendant forms are highly attractive and apparently they are appropriate for lilies. In fact, there are such a huge number of graceful lily species as well as hybrids that prospects beckon from every side.
If you are into breeding lilies, it is advisable that you make a list of your personal aims according to priority. After the flowers are developed and in bloom you may be enticed to disseminate the pollen everywhere. In fact, you are likely to find a huge collection of seeds, which may require the entire country to sow and then nurture the plants that germinate from them. Alternatively, if you have been trying to develop crosses that are more extreme, it is possible that the pods will dry out and wither. In such cases, you may have nothing till another season. Hence, you need to strike a balance in order to ensure that you are working well within your resources in terms of time, energy as well as space. Some lily enthusiasts often pollinate just one bloom of a specific cross.
All said and done, there are a few guidelines which may be useful for all lily breeders. Firstly, since you are putting in some valuable time and space, you may possibly also be certain that the cross you are developing is proper and there is no foreign pollen making contact with the seed parent by means of an insect carrier or wind. Ensure that you get rid of all the anthers of the seed (female) parents much before they allow any pollen to drop. At the same time, envelop the stigma using a foil cap. You may either self-pollinate the most healthy and robust seedlings or back-cross them with their parents. When you do this, it will ensure that you have some possibility of gaining from the factors that are governed recessively. Nurture the maximum number of seedlings possible from the crosses. This is the only way wherein you will get some idea regarding the cross’ genetic potential.
If has been found that when two lilies are related more closely normally they will mate more easily and certainly. While some lilies are extremely productive to their own pollens, there are several others that may be partially or completely inhibited. Then again, if the fertility of one of the parents is uncertain, it is prudent to use that plant as the male parent, with all other things being the same. Perhaps, an ovary has the ability to hold just a little over a hundred gametes as ovules. However, there will be several thousand pollens that will certainly offer a better probability of fertile gametes.
It may prove to be virtually impossible or almost unfeasible to cross lilies of widely different types. Nevertheless, there may be rare exceptions which may produce the unusual seeds that may give rise to an entire new range of lilies. Plants developed by crossing different lily species and hybrids that belong to various specific groups or divisions of hybrids can occur. However, you should not expect their success rate to be high. On most occasions, the seed pods harvested from such plants may be filled with chaff. Yet you may occasionally find a rare seed.
It seems that the barriers between lily divisions are constantly falling. Possibly, the succession of crosses between the Oriental lilies and the trumpet lilies are the most exciting. All these hybrids seem to have great vigour; and such strength coupled with the size and colors of their flowers promise wonderful things for your gardens. Presently, this series of lily hybrids is known as “Orienpets” – certainly not a very nice name for such wonderful flowering plants. Meanwhile, various other trumpet lilies, such as Lilium longiflorum, are also throwing off restraint and becoming independent. Already a series of hybrids from crossing t. longiflorum with Asiatic hybrids are available on the market.
Fertility and infertility
There may be several reasons why specific crosses do not yield seed. One of the reasons could be a problem with the hybrid’s chromosome count. In addition, there may be a simpler problem, for instance, the pollen (male) parent may possess pollens that have been altered genetically so that they travel a particular distance from the style downward to the ovary of the seed (female) parent. In fact, this distance may often be less than what is needed for the selected seed parent. The simple solution would be to develop a completely reverse cross using the same parents. This should provide you with an identical genetic mix.
On the other hand, if you doubt that the length of the style is the main problem, you can turn to surgery and remove a portion of the style and bring the pollen in contact with the abridged style. You may cut the style down to just 1 cm (1/2 inch). In this case you will not have the nice, broad stigma to plaster the pollen on. Nevertheless, you can place several pollen grains even on a small surface. A number of breeders dampen the cut surface of the style using juices from the surface of the ripened stigma. It has been found to help the pollens to germinate quickly and also let them pass down to the ovary easily.
The more diverse the cross, the more dissimilar the parents, the chances are greater that there will be more problems with the pollen. In fact, developing crosses between dissimilar divisions can often prove to be problematic. There was a time when breeders thought that it was impossible to cross Orientals with trumpet lilies. The main problem is to prevail over the restraining mechanisms in the seed (female) parent that prevents or thwarts the progress of pollen from unwelcome suitors, resulting in the death of the pollen.
This problem can be solved by employing the supposed “mentor pollination method”. Several expert breeders place some irradiated (lightened) pollen on the seed parent’s stigma and these pollens grow downwards and set off the “intruder-alarm system”. However, they are unable to fertilize the ovules. The real pollen is brought in contact with the stigma of the seed parent roughly 24 hours later. Following this, everything else should go as per plan. There is a variation of the technique and it also seems to work well for all amateurs. Put a very little amount of pollen on the stigma of the seed parent that has already been identified as being compatible. The forerunner pollen will go down the style, turn off the rejection mechanism of the seed parent and will let the real pollen to go down freely within a period of 24 hours to 48 hours. This may possibly denote that there is a very small fraction of undesirable seed among those that are harvested. However, this is never a big price that one has to pay and you never know that this particular seed may spring a surprise by offering you something really good!
At times, the lily seedpods may distend well either uniformly or haphazardly and when they open up you may be shocked to see the expected seeds to be nothing but all chaff. The first impression that you are likely to have is that pollination has been unsuccessful. However, this may not be the actual case. In effect, the embryos have developed, but they have been left deserted owing to the supporting endosperm cells‘ failure to develop. In fact, it is absolutely possible for any amateur grower to rip the embryos prematurely from the growing seed pod and subsequently culture them in sterilized nutrient mediums till they develop as minute plantlets, which can then be transferred to regular culture processes.
This task involves three main stages. First you need to prepare a sterile nutrient solution. Second, you should deliver the embryo taken from the seed and position it in the nutrient medium. Finally, the plantlets need to be transferred from the nutrient medium to the compost where you will be growing them.
It is possible to see the embryos present in transparent seeds, particularly easily when placed on a light box. The ideal time to undertake this task is when the seed pod is green, but the embryos have already formed inside the seeds. This may be roughly eight weeks following pollination, i.e. anything between 56 days and 60 days. However, it is important to ensure that the conditions are as sterile as possible.
Currently, hybridizers are breeding robust new tetraploid plants in many different divisions – something that has been named tetraploid breeding. Normally, a lily has a 12 pairs of chromosomes and these are known as diploids, usually written as 2n= 24. A diploid lily’s reproductive gametes, which include the egg plus the pollen cells, hold one group of chromosomes, i.e. n=12. Sometimes, in the wild as well as in cultivation, individual diploids mutate to develop into triploids, which actually have three chromosome sets (3n=36). Some may even become tetraploids having four sets of chromosomes (4n=48).
It is only in extremely rare instances of mutation, diploids are interbred with diploids. In the same manner, tetraploids crossed with tetraploids will give rise to plants having the same polyploidy (cells or organisms having double or even more number of basic chromosomes). On the other hand, breeding a triploid with a tetraploid will produce seeds from which you may get both triploids as well as tetraploids. Similarly, when diploids are bred with tetraploids they can give seeds of triploids and tetraploids. However, the fertility level of these polyploids may be different. The pods of these plants may contain just a few seeds. Hence, if you desire to cross plants having dissimilar chromosome counts, you ought to plan in a way where you utilize the higher polyploid as the male parent.
Moreover, the dissimilarity between diploid and tetraploid lilies can often be remarkable. There are several benefits associated with such breeding, including larger flowers, broader petals all having thicker texture; more robust plants having stronger foliage and stems; longer flowering period; plant with bulbs have more productive capabilities; more resistance to diseases; and easier to breed with triploids resulting in a growing number of tetraploids.
At the same time, some dangers may also be involved in such type of breeding. For instance, some flowers may lose some of their elegance in the process. Furthermore, in a number of tetraploids, the buds have a propensity to become further breakable. However, it is expected that this problem will be gradually overcome as more and more selection occurs.