F1, F2 and All That
By Peter Peroz

At the September 2005) general meeting of the Bromeliad Society of Queensland, there was a lively discussion as to the definition of F1 and F2 bromeliad hybrids. My reference in these matters is ‘A Dictionary of Biology’ by Abercrombie, Hickman & Johnson.

“ F1 (First Filial Generation) The offspring resulting from crossing plants or animals of parental generation (P1) from which an experiment starts.
F2 (Second Filial Generation) The offspring resulting from crossing members of the F1 generation among themselves.”
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Back Cross. (Usually applied to animal breeding) The crossing of a plant with a plant from an earlier parental generation. (Used to try to intensify a desirable trait)
Reverse (Reciprocal) Cross A cross from the same parents; exchanging the role of seed and pollen parent.
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Primary Cross The F1 generation.
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David Benzing, in his book ‘ The Biology of Bromeliads’ has an excellent chapter on bromeliad hybridisation (page 266). Although published in 1980, his comments are still relevant. Recommended reading for a newcomer to bromeliads interested in creating bromeliad hybrids.

Q. (Peter Paroz)
What is the status of crosses between two varieties of a species ??
My understanding is that the progeny would not constitute a hybrid. However under the present naming rules for hybrids, these can be registered with a hybrid name!! Also, I gather that this could apply to a superior specimen selected from a batch of species seedlings. ??
A. (Derek Butcher)
There will always be discussions on seed raising. Although not defined, Benzing suggests that a species is a collection of plants that can reproduce themselves from seed. A variety does the same. But this seems to be ignored by some taxonomists; for example a variety called variegata! If a species does not reproduce from seed within the species description, then the plant is a hybrid in my view.
If you have a stable species crossed with any stable species, then it is a primary hybrid or F1. Remember that some taxa are described as species but are natural hybrids!! All other crossings are secondary F2, or tertiary F3 etc. Varieties that are intra-species and are crossed cause a bit of a dilemma but if the progeny are within the species description then surely they should be identified as such. For example how did ‘Pickinny’ come into being?. If you grow this from self set seed and you don’t get seedlings like ‘Pickinny’ but within Ae. orlandiana species description, then surely these are Ae. orlandiana.
Cultivar names should only be given if they have features that make them outstanding from the ‘normal’ species. Variegated plants really stand out but some of the other ones that are given Cultivar names make you wonder if the person really knows the species or are after a quick buck.
A cultivar is not necessarily a hybrid but all hybrids are cultivars!