Splash and Dash equals Bad Technique?

A meeting place for rose breeders.
Post Reply
rikuhelin1
Posts: 225
Joined: Sat Jul 16, 2016 7:56 pm

Splash and Dash equals Bad Technique?

Post: # 72158Post rikuhelin1
Tue Sep 29, 2020 12:21 pm

Can a small hip (with seed) relative to self-pollination hips indicate “not“ enough pollen applied or repetition required ?

I usually only use a splash and dash method - and sometimes honey if note lack if adherence - don't normally do repetitive pollination. Inquiring as noticed this year some of my spinos pollinated hips half the size of selfies on same rose.

Don
Posts: 1873
Joined: Wed Dec 31, 1969 7:00 pm

Re: Splash and Dash equals Bad Technique?

Post: # 72160Post Don
Tue Sep 29, 2020 9:37 pm

That's a really good question.

For sure it means that you did a good job of emasculation. Whether the pollen was then applied in sufficient amount to effect a successful pollination is a function of the compatibility of the pollen with respect to self-incompatibility (SI) genes and with respect to chromosomal homology. Another possibility is that the pollen is only partly viable.

There is not much you can do if the pollen triggers an SI mechanism. You can expect to get some seeds in this case but they would have no embryos. A lot of seeds form without embryos. So a small hip with a few seeds having no embryos means there's probably an SI mechanism at play.

However you can get the same outcome from a successful pollination where the dna is simply not homologous enough to generate a viable embryo.

If you do get a viable embryo then it is likely that the pollen used was only partly viable and you would indeed benefit from swamping the stigmata with it.

I should mention that apomixis can happen too which could also give a small hip with few seeds.

Finally, it is almost impossible to do a complete job of emasculation. I did an experiment once where I not only emasculated the hips but flushed them with copious amounts of water and still got some selfling seeds - small hips with small numbers of seeds.
What doesn't kill them makes them stronger.

mntlover
Posts: 257
Joined: Sat Dec 29, 2018 7:11 pm

Re: Splash and Dash equals Bad Technique?

Post: # 72161Post mntlover
Tue Sep 29, 2020 10:40 pm

Thanks for asking this question, and also for the response.
I usually pollinate two or three times, if I have time. I have been wondering at times if I am waisting too much pollen. I am curious what you all do? Do you keep track of pollens successfulness? Look at pollen ahead of time for viability? Consider from experience likelihood of compatibility? Sometimes I have plenty of pollen to spare of some varieties, but there certainly are those I run out of long before I would like to.
I was wondering if it might be better to try to only do once when they are receptive, at least with my limited pollens.
Duane

rikuhelin1
Posts: 225
Joined: Sat Jul 16, 2016 7:56 pm

Re: Splash and Dash equals Bad Technique?

Post: # 72162Post rikuhelin1
Wed Sep 30, 2020 12:44 am

Don

Thanks for taking the time for a very informative and enlightening reply of outcomes that can cause what l have seen. I should of mentioned another observation l noticed - all the selfies on the spino have passed through the red hip color phase to the black matured phase. The crosses are still at the red phase - weeks behind.

I now understand variables can play into preventing even what appears to be successful crossing (hip and seed produced) from being one. Never realized roses can produce hips that contain seeds that can be essentially termed “sterile”.

Don
Posts: 1873
Joined: Wed Dec 31, 1969 7:00 pm

Re: Splash and Dash equals Bad Technique?

Post: # 72163Post Don
Wed Sep 30, 2020 3:25 am

The float-sink test is a very reliable indicator of seeds having no embryo. Empty seeds float. It's not 100% but in my test it was 99%.
What doesn't kill them makes them stronger.

jbergeson
Posts: 1413
Joined: Thu Dec 15, 2011 11:54 pm

Re: Splash and Dash equals Bad Technique?

Post: # 72164Post jbergeson
Wed Sep 30, 2020 9:55 am

Good questions here and info from Don. I will now blab officiously about my own experiences as I sit on the couch waiting for the tea to shake off the stupor of what must have been a low-oxygen stuffy-nose night.

I've noticed before that certain pollens had a tendency of producing smaller than normal hips. Upon later examining the pollen under a microscope, it was largely misshapen globs with few or no fat ovals. Likewise some roses' pollen seems to make larger than normal hips.

Building on what Duane said, I like to strain out the anthers from my pollen and use it very fresh...the morning after collecting it, if possible, and no more than one day later. I use a paint brush and aim for a smother. Usually just one application, except in special circumstances. Having said that, I guess if I'm passing a hip the next day and still have some of the same pollen I'll hit it again. Above & Beyond is one rose that really seemed to benefit from re-pollinating later in the day. Occasionally I've had a rose that produced only small amounts of pollen, so I have used it more judiciously.

Duane, I do think that little pocket microscope that I've posted about on here is a great tool to know in advance some idea of how fertile a particular pollen is. Pollen with a low percentage of apparently viable grains will have to be applied at a much heavier rate.

mntlover
Posts: 257
Joined: Sat Dec 29, 2018 7:11 pm

Re: Splash and Dash equals Bad Technique?

Post: # 72165Post mntlover
Wed Sep 30, 2020 5:15 pm

Riku, I have noticed a difference of length in time it takes a hip to ripen from the same seed parent based (apparently) on different pollen parents. My hips were not a large difference in size as yours are, so may be different issues at work.
Joe, I have purchased the microscope you recommended. Had a lot of in with it until the move, need to find where it was packed. Maybe I need to consider using a visible check of the pollen as a determining factor of how much I slather on. Of course how much pollen there is will still be a factor.
I noticed the same thing with Above and Beyond, so I started hitting it three times. Didn't make it any less picky, but hips that took did really well.
Duane

rikuhelin1
Posts: 225
Joined: Sat Jul 16, 2016 7:56 pm

Re: Splash and Dash equals Bad Technique?

Post: # 72166Post rikuhelin1
Wed Sep 30, 2020 5:37 pm

Txs Duane for the info,

As fate would have it, between yesterday and today (cool night) the hips turned to 60 to 80% dark black with some dark red showing. This l take as a positive sign. However all crosses’ seed from this year will now be subjected to medieval truthing by water trial. Effort justified as l do not do “dozens” of one cross each - beats waiting eons to see if they germinate only discover they never had a chance.

pacificjade
Posts: 751
Joined: Sat Dec 17, 2011 12:15 am

Re: Splash and Dash equals Bad Technique?

Post: # 72167Post pacificjade
Wed Sep 30, 2020 5:43 pm

I use splash and dash for new roses, seedlings I want to test. It's all about the metrics, and you have to go go go during pollination season.

I take my time and often repeat the day after on important mother plants that will give me a lot of what I want or a plant that I would be okay with one miracle seedling from so I can quickly ditch the problematic parent once I obtain some of the rare genetics required.

Everything has its time and place.

Don't overthink this one. Pollination season is short. Emphasize your energy efficiently.

Post Reply