DEVELOPMENT OF F-1 HYBRIDS IN CYCLAMEN

H.S. Asma
Since decades, the cyclamen has belonged to the group of the most appreciated houseplants. As an eloquent evidence of this I remark that the world-seedproduction per annum amounts to 100–125 million seeds. However, both to the consumer and to the grower this popular plant offers a number of disadvantages, which, in the long run, will affect its use adversely. The rapid increase in centrally heated private-homes is not conducive to the use, as, indeed, the optimal temperature for the growth and flowering of the cyclamen averages around 15°C, whereas man feels comfortable at a temperature round 20°C. This higher temperature has a strongly negative influence on the development of the foliage, bud formation and the floridity of the cyclamen.

Also for the grower some negative aspects are connected with the cyclamen-culture:

Firstly, the rather long growing-period in comparison with other pot-plants. By technical growing-measures this obstacle can partly be broken down, however, in some cases these measures have an adverse effect on the durability of the plants.

Secondly, the susceptibility of the cyclamen of a number of diseases with its attending labour intensive control methods. For example, the removal of symptoms of rotting.

Thirdly, the comparatively small percentage of plants of "first-rate" quality that can be grown of a certain lot, and the high percentage "rejects" that have to be removed during the period of growth, sometimes even up to 35%.

In the fourth place, the large variation occurring in many cultivars in respect to the plant habit, the colour and shape of the flower.

Any successful attempt to turn the negative points mentioned to positive ones, contributes to the permanent popularity of the cyclamen.

Talking about the positive points, I mention the appointment of the "Laboratorium voor Tuinbouwplantenteelt" in Wageningen (Holland) to "International Registration Authority" for cyclamen, by the "International Committee on Horticultural Nomenclature and Registration". This took place on the 15th International Horticultural Congress in 1958 in Nice.

In Wageningen a very large number of cultivars were judged and analysed and the number of chromosomen established. From the results of the tests it appeared that though the greater part of the current assortment consists of tetraploid cultivars, diploid cultivars are grown as well in practically all known cyclamen colours.

The drawbacks I mentioned, together with this scientific research in Wageningen, induced Royal Sluis, one of the internationally well-known seed-companies in Holland, to occupy itself intensively with the grading up of the cyclamen. In doing so, the following growing-target was in view:

Asma, H.S. (1973). DEVELOPMENT OF F-1 HYBRIDS IN CYCLAMEN. Acta Hortic. 31, 145-148
DOI: 10.17660/ActaHortic.1973.31.20
https://doi.org/10.17660/ActaHortic.1973.31.20
31_20
145-148

Acta Horticulturae