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Author Topic: Long term cold hardy citrus breeding project  (Read 24740 times)

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #150 on: January 15, 2019, 04:10:38 PM »
Stan sent me some US 852 fruit.  As I reported back then, they were much too sour, but the juice was OK diluted with water and sweetened.
Eyecker sent me a (clem x trifoliate) x clem fruit.  It was much better, more sour than I like, but not bad.
So now I've tasted a half mandarine half trifoliate, and 3/4 mandarin, 1/4 trifoliate.  I've tasted only one variety of each type.  Truely this is a sample size too small to mean much.  But in my mind I'm extrapolating anyway.  Very encouraging.

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #151 on: January 15, 2019, 04:17:11 PM »
Eyecker also sent 15 Taitri fruit.  Only the best 3 were worthy of making lemonade.  But the 15 fruit contained 500 seeds which are planted.  I hadn't planned to breed lemons, but they are this really big group of F2 seeds to come along.  It will be a chance to look at a big F2 population, unless they are mostly nucelar.  I tend to get ahead of myself.

SoCal2warm

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Re: Long term cold hardy citrus breeding project
« Reply #152 on: January 15, 2019, 11:20:00 PM »
Walt, I suggest you make an acquaintance in the area who would be able to carry on your long term hardy citrus breeding project if something were to happen to you. You have to think ahead and plan beyond your lifetime.

I have read of many results of long-term fruit breeding being totally lost when the original person carrying on the experiments died. Such a shame. I'd hope that doesn't happen in your case.

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #153 on: January 17, 2019, 02:28:09 PM »
Actually I'm looking into forming an LLC to inherit the ground and plants and all rights to them.  My 2 children will be members of board of directers, to help see my plans continue.  But I will need directers who are deeply committed to citrus growing and breeding.  Anyone can PM me if interested.  Or I guess you could write me here.  I'm not trying to hide anything.

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #154 on: February 04, 2019, 02:05:25 PM »
Taitri seedlings are finally germinating.  I think they were so slow because we were keeping our house cool to save heating cost.  Now I hope the (clem x tri) x clem will be germinating soon.

SoCal2warm

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Re: Long term cold hardy citrus breeding project
« Reply #155 on: February 04, 2019, 06:08:24 PM »
Taitri seedlings are finally germinating.  I think they were so slow because we were keeping our house cool to save heating cost. 
Taitri was very slow germinating for me as well. Noticeably so.

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #156 on: February 05, 2019, 11:49:25 AM »
What percent of seedlings are zygotic?

SoCal2warm

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Re: Long term cold hardy citrus breeding project
« Reply #157 on: February 05, 2019, 11:54:16 AM »
What percent of seedlings are zygotic?
I think what you're actually asking is how many of the seeds were not polyembryonic ?
(As you know it's not necessarily such an easy thing to figure out if they are actually zygotic)

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #158 on: February 05, 2019, 12:16:36 PM »
Yes, I've learned that first hand.  Some zygotics may look liker their mothers.  And some polyembryonics have delays between first and second seedlings from the seeds.  So I'm hoping for any guesses on what to expect.   Anyone have experience with F2 Taitri?

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #159 on: February 12, 2019, 11:58:43 AM »
Recently I printed this thread and re-read it all, marking things I'd missed and should respond to.
Several times I've written that I'll be growing 200 seedlings per population per generation.  Not the same thing at all.  With 9 populations, that would be 1800 seedlings per generation.  But I've decided I won't be doing population 9.  And population 1, pure P. trifoliata, will be a much smaller population.  All I'll be doing with population 1 will combine precocity, lack of nasty ponciris flavor, and high percent zygotic seeds.  That doesn't require 200 seedlings.  So I'm down to 1400 seedlings per generation.  By starting different populations in different years, I will be starting 200 to 400 seedlings per year.  However, I'm now planning on doing it with mandarins and with finger limes.  That means 400 or more seedlings per year.  I can do that.


Walt

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Re: Long term cold hardy citrus breeding project
« Reply #160 on: April 02, 2019, 02:40:31 PM »
I don't have numbers, but Taitri has had very few polyembryonic seeds.  Good.
For over a week, I;ve had my older trees outside, bring them in when freeze is predicted.  But today I took almost all my seedlings outside.  45 pots.  Many have several seedlings, so much of this week I will be seperating them and putting the in bigger pots.  Soon the Flying Dragon and precocious Pt can go in the ground.   

SoCal2warm

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Re: Long term cold hardy citrus breeding project
« Reply #161 on: April 02, 2019, 09:30:29 PM »
I don't have numbers, but Taitri has had very few polyembryonic seeds. 
Of the three Taitri seedlings that sprouted for me, one of the seeds had two seedlings sprout from it.

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #162 on: April 03, 2019, 11:40:25 AM »
This morning I spent much time thinking about Kumin's results from growng some 3000 F2 citrange seedlings. It seems selecting for winter hardiness will be easier than I thought.  I'm sure much fine tuning will be needed, but just surviving isn't as hard as I thought.  And then there is flavor.
I thought getting rid of the extreme sourness of P. trifoliata hybrids would be a long process, over many generations.
So I googled inheritance of sour in citrus.  I got several papers, but here is one that puts it in laymans terms.
https://www.sciencedaily.com/releases/2019/03/190305100651.htm
Basicly, it says there are 2 main genes controling much of the sourness in citrus.  I'm sure there are many modifier genes , but it looks like reducing acid will also be much easier than I thought.

Ilya11

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Re: Long term cold hardy citrus breeding project
« Reply #163 on: April 03, 2019, 01:59:41 PM »
These two genes are regulated by several other genes, different mutations in them result in so called acidless forms of pomelo, lemon and orange.
These mutations  should be present in two copies ( homozygote state) in order to prevent accumulation of citrate and acidification  of fruit vesicles.
So, in order to get a sweet hybrid, the easiest way is to cross poncirus with acid-less orange and then select for sweet F2 progeny.
Here is a full text of the article.
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mikkel

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Re: Long term cold hardy citrus breeding project
« Reply #164 on: April 03, 2019, 03:34:22 PM »
If I understand it right certain traits controlled by multiple genes are always expresses like the Gaussian distribution curve in the offspring . Which would suggest if you only have a large amount of offspring you always can find the desired level of expression of this certain trait. (if it is inside the possible range of the gaussian bell)
Mass selection is easier to manage in annuals but in theory also possible in trees like Citrus.
Am I right?

Ilya11

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Re: Long term cold hardy citrus breeding project
« Reply #165 on: April 03, 2019, 06:33:29 PM »
If I understand it right certain traits controlled by multiple genes are always expresses like the Gaussian distribution curve in the offspring . Which would suggest if you only have a large amount of offspring you always can find the desired level of expression of this certain trait. (if it is inside the possible range of the gaussian bell)
Mass selection is easier to manage in annuals but in theory also possible in trees like Citrus.
Am I right?
Yes, most of the traits are polygenic, that is a phenotype is determined by several interacting genes. But according to this paper the acidless phenotype, at least in the case of pomelo and Rangpur lime, is recessive,  so you need two copies of mutated genes.
Best regards,
                       Ilya

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #166 on: May 19, 2019, 03:11:10 PM »
I really think an acidless Pt would be preferable to one with just the bad poncirus removed.  Poncirus hybrids I've eaten are much too sour.  Mixing juice of US 852, for example, with an acidless poncirus+  F2 hybrid might make a very nice juice.
That isn't my final goal, of course, but a step along the way.
« Last Edit: May 19, 2019, 03:21:42 PM by Walt »

SoCal2warm

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Re: Long term cold hardy citrus breeding project
« Reply #167 on: May 19, 2019, 05:37:53 PM »
Thomasville citrangequat almost doesn't have any poncirus flavor, so that's an example of a second generation hybrid right there.

Ilya11

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Re: Long term cold hardy citrus breeding project
« Reply #168 on: May 20, 2019, 03:50:13 AM »
Tomasville, even semi-ripe, does not at all have any poncirus off-flavors.
Best regards,
                       Ilya

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #169 on: May 20, 2019, 03:14:49 PM »
Got to get one,  Or get someone to make the cross for me.

SoCal2warm

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Re: Long term cold hardy citrus breeding project
« Reply #170 on: May 20, 2019, 03:58:45 PM »
Got to get one,  Or get someone to make the cross for me.
It's a zone 8 variety, maybe 7b under optimal conditions.
Are you thinking about trying to backcross it back with trifoliate?

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #171 on: May 31, 2019, 01:27:16 PM »

Yes, among other things.

 

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