Hybridizing in large collections

[janemcgary]

I'm busy packeting seeds for the SX. One donor offers many different species in a few South African genera. It made me wonder how likely it is that coming from such a large collection, the seed lots will produce hybrids. I know my Narcissus have hybridized over the  years. I don't grow South African bulbs, since I have no heated facility. If you've grown SX seeds, have you seen many likely hybrids among the resulting plants?

[Uli]

Hello Jane,

You are raising an important point. I am asking myself the same question. I know that it is a common problem with Lachenalia which tend to hybridize. If I want to produce pure seed I remove the pot in question from the collection, place it as far away as possible from the others and do hand pollination. The plants have to be kept apart until flowering is over. 
I am not here in my new garden for long enough to be able to assess if this method is good enough, my own seedlings of my own seed have not yet flowered.
Aloe are not geophytes but open pollinated Aloe seed from collections must always be considered hybrid seed.
I will come back to this topic in due course
Uli 

[Steve Marak]

I agree this is an important point and I suspect the answer depends on the the grower, i.e., those who are aware of and concerned about the issue take care to avoid it, or clearly mark the seed as open-pollinated. And I think it's great that people donate OP seed.

When I want to be sure, I protect the inflorescence from insects (and, sometimes, hummingbirds) for the entire time of flowering. I also have some rules of thumb. If I've grown it for at least a few years and never had any spontaneous seed set, I assume no hybridization. Likewise if there's nothing closely related flowering at the same time, especially during cold weather when the greenhouse is closed and fewer flying insects are around. And there are a few things, e.g. Hippeastrum striatum, which set copious seed every flowering without help. Otherwise I assume there's a reasonable chance of hybridization and mark as OP.

I can't recall anything from SX seed that seemed a likely hybrid except things that were marked as OP. But I'm not confident I'd know, unless it was a species with which I was very familiar, and of course I rarely request those.

Steve

[Michael Mace]

how likely it is that coming from such a large collection, the seed lots will produce hybrids

I think it depends on the species. For example, among the Moraea species I grow, the blue and purple species appear to be very attractive to honeybees and set seed heavily if left to themselves. But the orange flowers do not get visitors in California, and usually do not set seeds on their own. There are also some species (Moraea gigandra, for example) that don't have stamens in the right position to touch the bees. They're adapted to beetle pollination, and the beetles that service them don't live on my continent.

Anyway, because there's a lot of insect-driven pollination, I grow all of my collection in screenhouses now. If I weren't doing that, I would break the petals off the flowers that I hand-pollinate. If there are no petals to signal to them, the insects won't come to the flowers.