I’m wondering if anyone knows of any research papers that discuss rose pollen germination as a function of temperature?
Do you mean on a stigma outside, or on a glass slide in a lab? There might be something on the latter for roses, but I’ve never see anything on natural conditions. I think there are studies on growth of the pollen tube in the stigma for various plant species, like lilies and brassicas. Just do a google search and some leads will show up.
Do you mean on a stigma outside, or on a glass slide in a lab?
I doubt it makes much difference but I’m asking because it has been fairly cold and rainy here over the last week. I shelter my pollinated blooms from rain for a day or two in order to prevent the pollen from washing out. It would be useful to have some idea how long it actually takes for the pollen to germinate.
Hi Don,
In the lab with the germination assays I’ve done pollen germinates fast and in a couple / few hours there are pollen tubes that can be up to 30x the width of the pollen grain at times. I suspect they probably germinate fast on the stigmatic surface, but then as they have to work their way through the style things are slower in order to do that. In the past I did some stylar squashes with potato to show germination and pollen tube growth in styles. As the pollen tubes grow they leave plugs behind and those can florese under UV light and appropriate stains.
It would be fun to follow pollen tubes at different temeratures and see their growth rates. I would suspect it differs across germplam some. There of course is the idea of gametic selection and that somewhere close to half of the genes that are experessed in the typical plant can be expressed in the pollen and cooler temerature tolerance may be what you’re going to be selecting for which won’t be bad if that is true. Those grains that segregate for more genes that would contribute to it would have a better chance at getting through. Selecting for greater chilling tolerance is something that was successfully done in tomato if I remember right.
Take Care,
David
P.S. Years ago I had some Carefree Beauty roses at room temp and in a cooler at 55F or so and pollinated them with the same male that would be segregating for cold hardiness to see if I could tell a general difference in overall cold hardiness in the offspring groups. Unfortunately, I had a hard time getting much in numbers from the cold pollinations.