Having neglected my project for too long, I feel it’s high time I jumped back into the fray. I placed an order on GRIN’s database with vague inklings of different possibilities… It’s been a few days, and a wave of inspiration hit me like a freight train! So many ideas bouncing around, I can barely keep up. I really should be putting this on paper, but I’ll let this forum post count for it.
I ordered seed from Rubus hawaiiensis and cuttings of R. pentalobus… I’m not sure what to do with either of them yet. I gotta check the documents again to remember R.p.'s ploidy level, but R.h. should be diploid. More closely related to the thimbleberry if I remember correctly, but R.h. can cross readily enough with the domestic raspberry. The reports don’t sound too promising, given that it’s bitter tones tend to end up in the progeny as well, but maybe some backcrossing can take care of that. I tried ordering cuttings from other raspberries (red, yellow and black) and some blackberries & hybrids, but they don’t seem to have much available right now, if anything. For the time being, what I have to work with is those two, Caroline, Prime Ark Freedom and Wild Treasure. I had Black Hawk, but I lost it; I aim to replace it with Niwot and/or Ohio Treasure when I get the chance. A lot of other brambles on my wish-list, but I won’t go into it right now.
Far more complex with possibilities are the number of strawberries I ordered. I already have Reine des Vallees Alpine and Mara des Bois (plus I recently bought an Alpine seed collection that includes Pineapple Crush, Yellow Wonder, White Soul and Ivory). I wanted to order Hawaii-4 and a chromosome doubled (4x) Mignonette, but they’re not currently available through GRIN. What I did get to order from GRIN were several Garden Strawberries (F. x ananassa, 8x – Fern, Aromas, Diamante, Guelph S01, White D and Mieze Schindler), one Scarlet Strawberry (F. virginiana, 8x – Intensity), several Musk Strawberries (F. moschata, 6x – Capron, Profumata di Tortona, 2 more female accessions and a male), one day-neutral F. x bifera (2x – F. vesca x viridis), several Comarum Hybrids (10x – Frel, Lipstick, Rosalyne), two F. x vescana (10x – Sara, Rebecka), and a complex semi-fertile hybrid (8x– F. x vescana “Florika” X moschata). I don’t know what to expect with that last hybrid… F. x ananassa is the descendant of an 8x virginiana x chiloensis cross. Crossed with a chromosome doubled (4x) vesca, you get the aromatic 10x vescana (it should’ve been 6x, I’m guessing a haploid “doubled vesca” gamete fused with an unreduced ananassa gamete). Then crossed with 6x moschata, you get this 8x plant. Should be interesting.
What I find interesting in the potential for strawberry breeding (besides the range of flavors and textures between the species) is the ploidy hopping that might be used to bridge otherwise uncrossable species (I’m trying to avoid odd ploidy levels). Moschata, in particular, seems a wonderful bridge between the lower and higher ploidy levels, and its dioecy would simplify the initial breeding attempts. Moschata could be bred to vescana (as in that last hybrid) or a Comarum hybrid to make a highly aromatic octaploid that could be bred into ananassa. Moschata could also be bred with diploid vesca and bifera to make tetraploids; these could then be crossed with octaploids to make hexaploids or decaploids (depending on whether or not the gametes reduce). Hexaploids could be backcrossed with diploids for further tetraploids, or with moschata for further hexaploids (and so bring in new traits to the moschata genome – day-neutral, bigger berries, greater production, monoecy, etc.). Backcrossing decaploids would yield octaploids for further crossing with ananassa, with the vescana x moschata hybrids, or with the tetraploids for further ploidy hopping. You could keep jumping back and forth between the different ploidy levels by using moschata (and any hexaploid progeny) as a bridge. All of this assuming that fertility wouldn’t turn into an issue (maybe all this ploidy hopping would turn the chromosomes into a pretzel). I wonder if I’m reinventing the wheel with a breakthrough someone else already had, but if I am, I haven’t actually seen this ploidy-hopping plan mentioned anywhere else.
I’ve heard of one breeding program trying to cross moschata into ananassa (link here: Berried Treasure | Science | Smithsonian Magazine), and they’re finding it difficult to get the flavor right because of how complex the aromatic compounds are for moschata (never mind the ploidy issues). I’m thinking of trying the reverse… Rather than breeding a complicated flavor into ananassa, we might breed size, yield and other traits into moschata (that is, keeping the genetics mostly moschata). We might even consider a pure moschata breeding program, though that’s outside the scope of my hybrid projects.
I haven’t given up on crossing 2x raspberry with 2x strawberry, but now I’m hoping to test 2x raspberry with 6x musk strawberry. I might get a tetraploid out of it. The strawberry’s dioecy makes it easier to make the cross without having to emasculate the flowers, but its short season could complicate things if I can’t get flowering times to match up. Maybe if I develop a dioecious female day-neutral hexaploid strawberry? Too many steps for my liking, but it’s an option. Day-neutral & everbearing are really the best options for the tropics. It doesn’t make sense to grow berries with one explosive harvest season when they could be bearing all year long in this climate.
Besides brambles and strawberries, I ordered Medlar & Hawthorn (Tejocote & C. monogyna) to cross with each other, as well as Quince and three Apple scions (no rootstock, I’m hoping they’ll function as cuttings, and said so in the order form). Chestnut Rose (Rosa roxburghii, 2x) to cross with the brambles, with the strawberries, and with the Apples (an alternative version of Schoener’s pomifera hybrid). A couple of Rowan hybrid scions (also as cuttings; Likyornaya & Granatnaya) and Currant seeds to test in my local climate, and several kiwi varieties to cross arguta with chinensis.
I have enough projects here to keep me busy for a lifetime. There was a point where I should’ve stopped and I have clearly passed it… But let’s keep going and see what happens.