Can cactus flowers, yet to open on a cutting - be pollinated and bear?

[CβL]

Yeah, so basically I've got a cutting that's about to flower again (there's some fruit on it), and I have some pollen in the fridge (fresh from today). I'd guess the flowers would open within 2 weeks, and I have small artist brushes. The final hurdle - can these pollinated flowers bear fruit? I can't see any reason why not.

If anyone knows anything detailed about the topic, or has tried it themselves - please post. Otherwise I'll post here my results. The cross would be a peruvianus x terscheckioid.

[tripsis]

Yes, it's possible. Just did it myself a few weeks back on two separate unrooted cuttings. Three fruits on one cutting, one on the other.

[CβL]

Super.

So if it fails, then it's all my fault.

What did you cross together?

[Torsten]

It is not only possible, but often essential. The growth of the pollen tube that grows from the stigma to the ovary is determined by the length of the style of the species the pollen comes from. if you are putting pollen on a species with a different style length you will need to adjust your pollination moment to match. This is especially critical if you take pollen from a short style species/variety to a long style one as otherwise the fertilising opportunity has passed by the time the pollen tube arrives at the ovary.

There are some brugmansia crosses for example that can only be done by raping the closed flower.

[chilli]

There are some brugmansia crosses for example that can only be done by raping the closed flower.

 

Torsten, I didn't really understand what you are saying about short and long styles.. do you mean the length of the tube the flower comes out of? What does this have to do with whether a cutting can bear fruit?

[Stillman]

I think Torston is saying you can successfully pollinate an unopened flower by "raping it" ie cutting it open before it opens naturally, and manually pollinating. Which I have done to cacti flowers that don't actually open completely. Perhaps he didn't quite read all of the first post?

Edited January 15, 2012 by Stillman

[occidentalis]

The style is the filament that the female flower parts sit on (well the stigma sits on it, the ovary sits under it)

The pollen has to get from the stigma to the ovary in order to fertilise the ovary

It does so by growing a 'pollen tube' through the tissue of the style which allow the sperm to get into the ovary

As T said the length of that pollen tube is determined by the usual length of the style in the species the pollen comes from; however if you are making hybrids, that may be different(shorter) to the actual length of the style of the mother plant

In that case you'll need to pollinate them at a time when the flower is not fully mature; ie the style has not actually grown to its full length

hence the raping part!

However I think T may have missed the point of the question - as I understand it wasn't specifically about immature flowers, but about whether a flower on an unrooted cutting can successfully develop into a fruit.

[chilli]

Well I learned something new anyway.. I thought by style he just meant like a particular "style" I didn;t even know it had a specifica botanical usage!

[Torsten]

I didn't misread the question. A fruit is only possible upon fertilisation. Such fertilisation is only possible if the pollen tube reaches the ovary. Doesn't matter whether this is a cutting or potted plant, or whatever. When crossing non-identical flowers the pollentube growth has to be taken into account. But basically I replied to the question with a "yes, but....".

[CβL]

This is especially critical if you take pollen from a short style species/variety to a long style one as otherwise the fertilising opportunity has passed by the time the pollen tube arrives at the ovary.

Okay, well this just happens to be more or less what I am doing. The flower I took the pollen from was perhaps 20% shorter (it had wilted when I got ahold of it, so this might be off) than a normal peruvianus flower, and the peruvianus flower is as you know.

So what I think you're suggesting is to either pollinate as early as possible or "rape" the flower?

[Stillman]

i'm still not sure if a cutting has enough energy within itself to set and ripen fruit to seed collection point but a big piece of cacti probably could. I know some of my cacti take months for fruit to ripen.. Will be an interesting experiment none the less. I am still assuming the cutting is non rooted piece? take some pics if you can at various stages. I'm certainly not disbelieving in anyone's opinion I am more just really amazed at how much potential energy is in a piece of unrooted plant.

Edited January 16, 2012 by Stillman

[Torsten]

OK, I DID in fact misread the question. or rather not read it at all because it is in the header rather than the body of the post . My reply was to the body of the post.

As for the question in the header, a 30cm cutting can produce at least 3 or 4 fully formed pods in the first year and another couple in the second.

[CβL]

Well Stillman, it is a big piece. It's quite fat (as it came from a 2-3 metre tall plant), and is almost a metre long. It was severed the day that I got the pollen, so it hasn't yet wasted any energy on roots or new growth.

I have once before tried to pollinate a cutting that was rooting at the same time. I think my mistakes were:

A) Trying to root it at the same time, because:

........A.1) It was using its scarce energy to create roots.

........A.2) The section under the soil would not be able to photosynthesize (less energy again).

I used a q-tip/earbud to attempt to pollinate the flower. Let's just say it was as delicate as using a basketball for sodomy. Very little if any pollen made it.

C) The pollen came from an unopened flower, so it was perhaps immature. Unsure.

D) I only tried to pollinate once, instead of repeatedly over days.

So this time, I will hopefully stand a better chance of getting something.

The parents; should they successfully cross - are very special indeed, and I imagine the babies will be quite special indeed. :D

[Torsten]

I used a q-tip/earbud to attempt to pollinate the flower. Let's just say it was as delicate as using a basketball for sodomy.

I always use qtips for cactus pollinations as they are disposable. It is also easy to put several half qtips into a serum vial in the fridge for later use. That way over summer I usually have quite a collection fo pollen at my disposal.

The pollen came from an unopened flower, so it was perhaps immature. Unsure.

Did you actually see pollen? Pollen on trichs doesn't usually develop until the second half of the flowering cycle. Many plants do this - probably as a remnant of preventing self pollination. I have never seen pollen in an unopened trich, so not sure how you could use this for pollination.

[CβL]

I always use qtips for cactus pollinations as they are disposable. It is also easy to put several half qtips into a serum vial in the fridge for later use. That way over summer I usually have quite a collection fo pollen at my disposal.

Interesting. To be frank I don't know an awful lot about how flowers work. But before I try with a q-tip again - did you do anything to it? i.e. pull the wool out to make a brush? Or just use it as the firm baton it comes as?

Did you actually see pollen? Pollen on trichs doesn't usually develop until the second half of the flowering cycle. Many plants do this - probably as a remnant of preventing self pollination. I have never seen pollen in an unopened trich, so not sure how you could use this for pollination.

It's not a clear memory, but there was definitely yellow powder/paste on the tip of the q-tip. But it was not of the same "lightness" as viable pollen. It didn't have that greasy feel to it.

[CβL]

So I came home from work and found that the flowers had opened. I thought they were at least 4 days away.

So I took my brush, and my pollen out of the fridge, and rubbed the brush into the pollen bag vigorously multiple times (hello, lady readers) and then painted every single piece of the stigma that I possibly could (without disturbing the anthers of the flower), for at least half an hour.

I'm a little worried that the pollen was a bit too wet when it went into the fridge, but I'm hoping that it survived nonetheless. I'll repeat this in a few hours, as hopefully the pollen will be a bit dryer by then.

Here's a few photos of the cutting in question.

[CβL]

Seems to be just me posting...

Anyway, later on that night I went back out (it was maybe 11pm), and saw that the flowers had opened fully. It was a spectacular sight, but my pride was muted due to all of my flowers having come from plants I'd gotten that were about to flower anyway.

I pollinated again, and as I suspected, the pollen was indeed wet beforehand and had dried by then. The brush had a fine coating of pollen, and I again painted each part of the stigma that I could.

In the morning, I did the same thing, and then moved the cutting more into the shade. I didn't have any paper bags, so I didn't put anything over them yet (better to risk insects screwing things up than to just outright kill the flower with a plastic bag).

I'm going to mark the base of the flowers with a sharpie so that I know which fruit came from which pollen, and then it's just fingers crossed.

I wonder which part of the stigma is most receptive?

What happens if a small amount of the receptor flower's own pollen gets onto its stigma - will it just select the acceptable pollen? Or will it abort?

How will I know when a fruit is ripe?

O_o