Number of pollen grains to use?

[lotis146]

So I see that, at least in the case of Phals, there's always two pollen grains (packs? pollinia?). When you pollinate another flower can you use just one and say pollinate another flower with the other grain? Or do you have to use both? I can imagine using both is "better" since you're doubling the amount of genetic material from the pollen parent, but again, do you have to?

Also I wonder, what happens if you pollinate one flower with pollen from two different plants, one grain from each? Is this a common practice? Big no-no? Freak accident waiting to happen?

Thanks for your knowledge and input!

[sweetjblue]

You don't have to use both pollen in the same plant , one will do the trick if its going to work at all. In fact you can split a pollen in half to use if you only have 2 and want to make severals crosses with it at the same time.

Using pollen from two different plants is not a common pratice and can be done, but then how are you going to tell the crosses apart? It's not like two separate pods.
You'd have to wait until each and every plant bloomed to know for sure which was which, and thats providing the 2 crosses would be vastly different enough from each other that you'd be able to tell. Not really a good idea unless you have a ton of room to grow out all those little seedlings that then become BIG plants


Just as a side note: I had read awhile ago ( can't find the article again) that somebody in Taiwan used 2 different pollen on the same plant several times. Their aim was to save time and space. According to the article this person did indeed get 2 successful crosses from one pod. Not exactly sure this is true now as both Ray and Fairorchids say otherwise.

[Ray]

Ray Rands, a late paph breeder and the inventor of the Air-Cone pot, used to try the "two-different dads" trick. There was some speculation that you'd get genes from both in a single maturing ovum, but that's wrong, as once it is fertilized by one, it will not accept it from another.

A little tip I have found to increase the likelihood of a cross "taking": using a toothpick, smash the pollinia on a piece of waxed paper, and then apply it to the viscidium.

[Fairorchids]

Different genera have different numbers of pollinia. For example, the original distinction between Cattleya & Laelia was 4 vs 8 pollinia.

Orchid pollen is not grainy like most other plants. In most genera, the pollen mass is attached to a short stem, with a very sticky pad that attaches to the pollinator, but the pollen itself is not that sticky, so it won't stick before it reaches the correct destination. In Paphs there is no stem, so the pollen mass itself is quite sticky.

It only takes one pollen to grow through to pollinate the orchid flower, but I know of no way to separate a single pollen out of the mass.

In Paphs you can divide the pollen mass, but one breeder told me not to divide it more than once. Another Paph breeder regularly pollinates a flower, then after 10-14 days he scrapes the remaining pollen off the stigma and pollinates a second flower. With very valuable pollen, he sometimes repeats the process to pollinate a third flower.

Doing double pollination would be silly, even if possible. You would not know which pollen was successfull, so you could not register the offspring.

In dog breeding it is common to use two couplings to improve the success rate, but it is always done with the same male.

[littlefrog]

I have used honey and spit to stick pollinia to stigma... Not at the same time though.

[DavidCampen]

Originally Posted by Fairorchids

It only takes one pollen to grow through to pollinate the orchid flower, but I know of no way to separate a single pollen out of the mass.

But a single pollen can fertilize only a single ovule thus producing only a single seed. Orchid seed pods contain many seeds. Would a seed pod even develop if only a single ovule was fertilized?

[Orchid Whisperer]

Originally Posted by lotis146

Also I wonder, what happens if you pollinate one flower with pollen from two different plants, one grain from each? Is this a common practice? Big no-no? Freak accident waiting to happen?

For reasons stated by others, you would not want to do this. You would never know which pollen parent had fertilized the plant. (sort of like allowing a prized female show dog to mate with one or more male dogs; you would never know the true parentage)

[lotis146]

Thanks everyone for entertaining my silly question! I know such a process would lead to uncertainty, I was mostly just curious if this was something Orchid enthusiasts tried given the number of seeds produced, like David pointed out.

It is interesting that Orchid pollen isn't like your typical understanding, the powdery yellow that drifts down from trees or gets stuck to the backs of bees. My recent attempt to pollinate 4 Phals was the first time I'd ever dealt with or really seen Orchid pollen. I put two pollen from the minis into the full-size while only one pollen in each mini from one full-size. It was one of the full-size with two mini pollen that took and is developing a pod so I was wondering if the one or two pollen factor was an issue.

Has anyone ever noticed major differences in overall success when you use two as opposed to one? For example, is there more genetic influence from the pollen parent when two are used?

Thanks for letting me pick your brain!

[Fairorchids]

Originally Posted by DavidCampen

But a single pollen can fertilize only a single ovule thus producing only a single seed. Orchid seed pods contain many seeds. Would a seed pod even develop if only a single ovule was fertilized?

Considering that orchids produce anywhere from thousands to one million plus seeds, I don't think that we are dealing with one pollen grain to one ovule, but I do not proclaim to be in the know on this.

One pro breeder whom I consulted made the statement, that 'you only need one pollen tube to get through'.

In other plant families, I know that it is one pollen grain to one seed. However, most plants produce few seeds (4-8 peas to a pod, 6-20 seeds in a daylily seed pod, etc.). The vast numbers in the orchid family makes it likely that there is a modification to the mechanics.

Could it be that the one ovule, once fertilized, produces the many many seeds?

[DavidCampen]

One pollen grain produces a single tube that will fertilize at most one ovule. This is true for orchids just like any other plant. The orchid's adaptation so that a single pod can contain many thousands of fertilized seeds is to package very many pollen grains into a single sticky mass so that they will all be transported as a package to a stigma.

I don't what the pro breeder was trying to say. You need a single pollen tube to fertilize a single ovule.

Here are a couple of photos showing pollen grains each developing their single tube.

Student Sheet 4 - Pollen Tube Growth - Science & Plants for Schools