North American Fruit Explorers mailing list at ibiblio

["Lon J. Rombough" <lonrom@hevanet.com>]

Title: Re: [NAFEX] Persimmon flower question.

I don't have the pedigree of Szukis, but from my plant breeding experience, if it is not such a close relative of the Early Golden group, I'd cross it with F-100, using the perfect flowers that each are able to set.  If they are such close relatives as Early Golden and Killen, in the other cross, that would reduce the likelyhood of inbreeding depression.  Further, since both are "males" that produce some perfect flowers, I suspect that some of the offspring might have the right genes to produce all perfect flowers.   Even a relatively low vigor type might not be that bad, if the fruit is good.  It could either be used as a dwarf, or grafted on the female types to both pollinate them and set fruit.
    I wrote up a theory of how this might work for POMONA some years ago.  
-Lon Rombough
Grapes, writing, consulting, my book, The Grape Grower, at http://www.bunchgrapes.com
Winner of the Garden Writers Association "Best Talent in Writing" award for 2003 


> Normally D. virginiana trees are either pistillate (female) or staminate (male). Rarely will a tree have flowers of both sexual _expression_. Szukis is one such that does and it is self pollinating. Szukis also has another oddity in that when grafted it can switch from bisexual to either pistillate or staminate and then when grafted again switch back to bisexual. It simply doesn't know which sex it wants to be!
>
> Some males will have perfect flowers and bear fruit. These males usually carry flowers in varying degrees of progression from pure male to perfect, and the fully progressed to perfect are the ones that can bear fruit. Claypool's F-100 is the best example of such a tree. The seeds from this male tree will germinate and grow into trees. 
>
> Some female trees will put on male flowers. I've not observed the progression like some males do, they are either purely pistillate or staminate. Early Golden, Killen, Garretson (the Early Golden family) all generally will put on a few stamina flowers and are self pollinating. This normally doesn't occur until the tree is fully mature. 
>
> Now for another piece of information you didn't ask about. The sexual _expression_ of persimmon is determined by two chromosomes labeled, X & O. Similar to the X & Y chromosomes in humans. Pistillate trees have two X chromosomes while the males have an X and O. Pollen from male trees have either an X or O and all eggs have X only because females have only x chromosomes to pass on. Likewise when a female tree puts on male flowers all the male sperm cells have X only. The result is all progeny of pollen from female trees will be XX or female. 
>
> Now before someone thinks, wow this is how I'll sell seedlings and guarantee they will bear fruit, inbreeding depression sets in and generally they are runts. Jim Claypool, the worlds greatest breeder of American persimmon thought he would breed some super persimmon by crossing Early Golden and Killen male flowers or Garretson with Garretson male flowers. All progeny were female and runts, with one or two exceptions.