In Lee Reich's amazing book, "Uncommon Fruits", it is said that Fragaria vesca, F. moschata, and F. x ananassa do not freely hybridize, being of distinctly different chromosome counts. Does this mean that there is practically (although not absolutely, perhaps) no chance of natural interspecific hybridization to occur without human intervention? Diospyros virginiana, D. lotus, and D. kaki are all 90-chromosome (D. virginiana var. virginiana - not D. virginiana var. pubescence, etc.) Yet, according to J. Lehman and Clifford England, both told me that there is no way for hybridization to occur naturally, that the flowers need to be 'tricked' into receiving the cross-specific polen.
The reason that I'm interested in these sort of questions is that I intend to breed superior cultivars of native fruits as I'm interested in promoting interest and awareness in native edibles and native plants in general.
So, could anyone tell me if I would need to avoid planting the following plants in my garden so as to avoid the possibility of inter-specific hybridization between native and non-native plants? I understand that no one could know all of the cross-fertile possibilities, but perhaps some of these will stand out as an obvious match (to be avoided). For instance, Morus rubra and Morus alba being cross-compatable, but not M. rubra with M. nigra, in which case of course I would not be planting any M. alba's. Same for the European filberts.
So, if you wouldn't mind looking over the following list and letting me know which plants I need to avoid, it would be greatley appreciated!
Native plants that I'm working on growing and/or breeding:
* Plums (Prunuscerasus: Prunus americana; P. allegheniensis; P. pumilla; P. nigra; P. angustifolia; P. maritima)
* Cherries (Prunus pennsylvanica; P. serotina)
* Strawberries (Fragaria vesca; F. virginiana)
* Hawthorns (Crataegus spp.)
* Fly Honeysuckle (Lonicera canadensis)
* Allium spp.
* Crab apples (Malus spp.)
* Chokeberries (Aronia/Photinia) & American mountain ash
* Currants/Gooseberries (i.e. Ribes americana; R. triste; etc.)
Non-native plants I was intending to plant, but will not if the may hybridize with the aforementioned:
* Plums (P. domestica; P. tomentosa; P. japonica/jacquemontii)
* Peaches/Neactarines (P. persica and hybrids with European or Asian plums)
* Sour cherry (P. cerasus and hybrids with P. avium)
* Garden chives and onion (Allium cepa & A. tuberosum)
* European Hawthorns (like Crataegus schraderiana)
* Oboe Strawberry (Fragaria moschata)
* Garden/Pine Strawberry (F. anannasa spp. anannasa)
* Honeyberry/Haskaps (Lonicera kamchatika/caerulea var. edulis)
* Sweet Almond (Prunus amygdalus)
* Currants/Gooseberries (R. nigrum; R. ussuriense; R. uva-crispa; R. rubrum; R. hirtellum x grossularia (R. hirtellum being native)
* Apple (Malus x domestica)
* Sweet Almond
* Pears (Asian & European)
I believe that Prunus tomentosa would present a problem for me (crossing with P. americana & P. maritima); I don't think Prunus domestica will be a problem.
I am not sure about Prunus cerasus. I suppose that the non-native strawberries will not hybridize (on their own) with the North American species due to differing chromosome counts.
I suppose although currants and gooseberries do not 'readily' cross-breed, is it a possible problem? I've never seen a large crab apple, so I guess that although crab apples can pollinate and cause to fruit M. x domestica, the pollination is never completed with an actual fertilization? I think the Hawthorns of the US and Europe would readily hybridize. I guess if the pears mixed with the mountain ash at least the seed would be infertile.
(Btw, what do you think would happen with planting Amelanchier alnifolia with A. arborea and A. canadensis, etc (all being natives). I don't think a smaller serviceberry would hybridize with the larger tree forms.)
Thank you very much,
Steven Covacci
Pears do naturally hybridize with mountain ash, and the result is a fruit called shipova, which is smaller than a regular pear. I am growing it in my yard. It is also available from One Green World, Raintree, and I think Burnt Ridge Nurseries.
Amy Iezzoni at Michigan State has done a lot of work with pie cherries, introducing new varieties from Hungary. I am growing one called Jubileum. Prunus cerasus is said to be able to pollinate prunus avium, but I don't think it changes the nature of the sweet cherry fruit.
John S
PDX OR
Steve, you're looking at doing a lot of the same things I've worked with or studied over the years (see my projects list at http://www.bunchgrapes.com for some of them) There's no way to answer all your questions on this forum - I'd be writing for days. Many of the crosses you are looking at have already been done, too. The improved plants just aren't widely known, or they aren't really an improvement.
There are a lot of reasons why species don't cross pollinate. Some bloom at separate times, some have biochemical incompatibility (pollen of one won' t grow on the stigmas of the other), etc. Some may cross readily, but produce sterile hybrids. There are ways around many of the problems, but in most instances two species don't just cross when planted next to each other. Or if they do, you would have to grow a lot of seedlings to find a few hybrids.
A good book to start with is Advances in Fruit Breeding by Janick.
-Lon Rombough
If you were just doing grapes, you'd have a lot less problems. Most of the Species of Vitis interbreed readily.
Of the other types, I've always thought a Salmon berry x Raspberry would be an awsome cross. Salmon berry is so very well adapted to our cool overcast weather, and seems happy to live at 'refrigerator temps'. A cross with a more flavorful rubus would be an excellent bridge.
The ploidy varies a great deal in Rubus and you will want to know what it is when trying to make a hybrid. I think that two hexaploids ought to cross readily like Maybe Tayberry x Kotata.
The Amelanchier does quite well, but lacks acidity and sharpness. I think there has been more work done in Canada on that species.
I think the 1937 USDA Yearbook has a good deal of information on this topic.
Idyllwild
simplepress
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Viron
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