Is it possible to cross a mulberry with a fig?

[xenil]

Hello,
A couple of days ago, when I was searching on the net for figs, I've found an interesting pdf about some Ukrainian fig cultivars.
I've found a variety called Smena, which is said to be an interspecific hybrid between the common fig, and the paper mulberry. It just came out of my mind if it possible to cross a fig with a paper mulberry, it might be possible to cross them with the common morus. The morus nigra is very common here, and its growing widely everywhere in zone 6b. What do you guys think about that? Is it possible to create hybrid between the two with home conditions, or is it need any special condition?
I think if it's possible it might be a new chance to prove the cold hardiness of the common fig.

[Kelby]

That's intriguing. I wasn't able to find any other references to this hybrid except that paper, have you seen anything? Mostly curious if there has been testing to ensure that it is an intergeneric hybrid and not just a fig...I'm admittedly a little skeptical. They are in different Tribes, to my knowledge most intergeneric hybrids (such as the various ones in the Apple Tribe, like Shipova) are in the same tribe and pretty similar in appearance.

Also, paper mulberry is in a different genus than black mulberry, so that could be another hurdle to further hybridization.

I hope it's real though, that could be a really neat fruit.

[xenil]

Unfortunately I didnt hear any further information, and I didn't find any reference to this hybrid, but the reason why I'm so sure in it is that this hybrid made by the Nikitsky Botanical Garden. Anyway thats an interesting topic to talk, there are maybe some other person who knows if it possible to make a cross between them, but as I heard there are tribe hybrids in the botany too. The biggest problem that the fig has a very unusual blossom, and I'm not sure that any other fruit can pollinate it or not?

[Kelby]

That is a good point, Nikitsky were the ones who figured out how to hybridize American and Kaki persimmons, apparently it took some pretty intense work to make it happen. Too bad the scientist who did it took the secret to his grave!

For what it's worth, I think one or two forum members are trying to do breeding/seedling selection with mountain figs from Iran. Supposedly those can survive -40F according to Wikipedia.

[xenil]

I think the iranian ones are could be hardier than a normal fig, but in my knowledge this difference between the cold hardiness is maybe 3 or 4 degrees. As I saw those pictures in my knowledge those figs looked like a ficus afghanistanica which is very common in Iran and has better cold hardiness at about -18 C, so thats why I think its a better way to prove the hardiness with a mulberry than to select one out from those seedlings.

and forgot to mention that sometimes the wikipedia can contain some false informations.

[Kelby]

Oh I believe it could be wrong, seems too good to be true. And that number has no source/citation, so who knows.

Perhaps it is F. afghanistanica, I couldn't say.

[GregMartin]

That is a good point, Nikitsky were the ones who figured out how to hybridize American and Kaki persimmons, apparently it took some pretty intense work to make it happen. Too bad the scientist who did it took the secret to his grave!

Kelby, I'm probably mistaken, but I thought that I'd read somewhere that this was achieved using mentor grafting along with a very small amount of pollen from the mother plant's species combined with large amounts of pollen from the father plant's species. I'll do a bit of digging.

At some point I'm hoping to get around to messing with that approach for figs and mulberries. Probably a waste of time, but we have to have our fun. I may also try high grafting figs onto a mulberry. I'm not sure how graft compatible they are, though.

[GregMartin]

Ok, after googling I dug up this info on persimmon breeding to get the virginiana x kaki crosses to take:

Rosseyanka originated in 1959 by Pasenkov at the Nikitsky Botanical Garden. He crossed a seedling no.213 of American Persimmon (female) with pollen of Asian Persimmon forms 48 and 145. A hybrid no. 18 has been grown up in vitro (laboratory conditions)and fruited in 1964 for the first time. It was named "Rosijanka".

The Russian success in hybridizing the two species was not simple or quick in reaching fruition. They attributed their eventual success to their practice of pollinating an Asian grafted on American rootstock with the pollen from an American grafted on Asian rootstock. There were a number of successful crosses achieved in this way, but apparently the Russians were most pleased with the variety they later named Rosseyanka, and this is the only virginiana X kaki of that series that is currently available in the U.S.

I didn't find any info regarding if mentor pollination was used in addition to the mentor grafting that was mentioned. Also, by saying that the hybrid was grown up in vitro makes me think that possibly they also needed to do an embryo rescue.

[Kelby]

Interesting, thanks for finding this Greg! Guess this was written before Nikita's Gift was bred? I can't imagine how the rootstocks would impact pollination, but plants are odd!

It would be great if the others were made available for further breeding work. David Lavergne in Louisiana is making new hybrids descended from Rosseyanka (Kassandra is one on the market) and Bass has made some crosses too, but I think his are still seedlings. England's is trialing a variety from David Lavergne currently called JT-02, which is apparently a cross of Josephine (D. Vir.90 Chrom.) X Taishu (PCNA Fruiting Female that produces some male flowers). Interesting stuff!

[GregMartin]

Very nice to hear about all the additional breeding...I'm ready to give them all cold hardiness trials!

It turns out that rootstocks can have a pronounced impact when they have been around for a long time and when the scion is very young, preferably a seedling. They call this mentor grafting because DNA can transfer from the rootstock to the scion via viral transfer....that's why the rootstock should have been around for a while, to accumulate viruses. I'm not sure of the specifics, but I read about a study where they did this with annuals and they inoculated the rootstock with an RNA virus which caused a significant jump in DNA transfer to the scion.

Presumably the rootstock ends up transferring genes to the scion that allow for some level of compatibility to occur where it wasn't previously. Mentor pollination is done by adding some inactivated pollen from the scion species to the active pollen of the species that you're trying to form the hybrid from. In this case the inactivated pollen provides chemicals that are required for the pollen to succeed that the other species' pollen lacks.

To me this is pretty interesting stuff and I'm glad that modern science is studying how this all works. It's been discovered that new species of plants have evolved by this route. DNA transfer between related species is a natural event by virus transfer via root grafts that then enabled cross-fertilization between the parent species.