Breeding for late flowering?

[walt]

I am still hopeful that some of Laaz's precocious trifoliata will give precocity in the F2 or a backcross.  I'm still hopeful that it is due to a single recessive gene.
But it has been around long enough that an F1 with each of several citrus species could have been grown out and either selfed or crossed back to the precocious trifoliata.  And so far I've heard of no results from such crosses.
I know you've said that your seedlings of this precocious line lack vigor.  I've read others have had that problem.  But others report that theirs are good plants.  I'm hoping that the lack of vigor is due to inbreeding depression.  People generally assume that trifoliata seeds are all apopmictice.  But that was thought about Flying Dragon until recently.  And now it is reported as 60% zygotic.  And one paper reports that zygotic trifoliata seedling are less vigorous than their apomictic counterparts.
And here's a question.  With seeds all from the same fruit, but some apomictic and some zygotic, should I call them siblings or parent/children.  I never thought about that until 3 sentences ago where I finally used the word counterpart. 
I've decided to try to find seedlings of  a mandarin or kumquat or fingerlime x Laaz's precocios trifoliata and cross it back to Laaz's precocious and see what gives.
I'll get back to you on it in a few years.

[imgrimmer]

Apr 23, 2018 14:57:53 GMT -5 walt said:

I am still hopeful that some of Laaz's precocious trifoliata will give precocity in the F2 or a backcross.  I'm still hopeful that it is due to a single recessive gene.

I wonder what is more helpful recessive or dominant. If it is a recessive gene and needs backcrossing each generation how to select against Poncirus traits?

Apr 23, 2018 14:57:53 GMT -5 walt said:

But it has been around long enough that an F1 with each of several citrus species could have been grown out and either selfed or crossed back to the precocious trifoliata.  And so far I've heard of no results from such crosses.

I know you've said that your seedlings of this precocious line lack vigor.  I've read others have had that problem.  But others report that theirs are good plants.  I'm hoping that the lack of vigor is due to inbreeding depression. 

I read somewhere that precocious flowering in Poncirus is easy to obtain via inbreeding. Given that and the lack of vigour in some seedlings could be a proof of its inbreed parentage

Apr 23, 2018 14:57:53 GMT -5 walt said:

I've decided to try to find seedlings of  a mandarin or kumquat or fingerlime x Laaz's precocios trifoliata and cross it back to Laaz's precocious and see what gives.

I like the idea of fingerlime x Laaz's precoccious trifoliata. It might be the best way to obtain precociousity as Fingerlime seedlings are said to be precocious up to 50%.

Another idea is to cross precocious Poncirus with Swamp Lemon to find an edible precocious Poncirus as a start for crossing with Citrus

Apr 23, 2018 14:57:53 GMT -5 walt said:

I'll get back to you on it in a few years.

I really like to know

When I find the papers I refer to I post them later.

[keen101 (Biolumo / Andrew B.)]

I like this idea. Good luck. I can see this as having lots of merit. The peach tree I think escaped frost damage this year but the flowers were still open before the last brief frost we got, so slower spring emergence would be better.

Perhaps just growing lots of offspring from this tree would produce an improvement simply from epigenetics.

One offspring has finally emerged after all these years.

I like the idea of keeping a bunch of small seed grown trees in pots and carefully watching and selecting. But the more genetic variation the better. Haha those strange flat peaches interest me. Very unusual.

[imgrimmer]

Apr 20, 2018 12:19:52 GMT -5 walt said:

Another interesting, to me, discovery.  
Some years back Some California peach breeders published that, after generations of selection in peaches which included selection for precocity, they had arrived at a point where enough of their seedlings bloomed by their second year that they would no longer concider any seedlings that did not bloom in their second year from seed. 

walt I just thought about that again. Could you post a link to that paper?

[walt]

It was years ago that I read it.  I think it will be hard to find.  But I'll see.  Google does great things sometimes.
And California has a very long growing season in the south.  I don't know which part peach breeding was being done in.  If the south, with very long growing season, the peaches might require an extra year for me.  

[imgrimmer]

I spoke to a amateur peach/apricot/plum breeder he raises all seedlings inside the greenhouse. Most of the seedlings flower within 3 years. Heat and a long season may help.
apricot seedlings I have take much longer until its first flower.