The KARMA Project

[ginger2778]

Originally Posted by bower

Hmmm I didn't see the question, but I will try my best to answer, as far as I know, and someone may correct or tell us more.

My understanding is that the "cherry" trait is = 2 locule fruit, not a one more.
(This is why I got saladette size fruit in my Kimberley X Zolotye Kupola F1. I thought Kimberley was a cherry, but technically it is not ie it has more than two locules).

The Kimberley revelation is enough to say something about cherry vs small fruit - the only way to tell is not fruit size but the strictly two locule condition.
You can certainly have cherry sized fruit that have more locules too.
They won't likely go on to throw larger fruit, as I think results tend to skew towards smaller fruit, although (or because?) size is a complex and additive trait. ("QTL"s).

What is really interesting is the difference it makes, when you cross a "non-cherry" cherry with a large fruit. Multi-locule small fruit are cool for breeding purposes. By contrast if you cross a true cherry (2 locules) with a larger fruit, the F1 will always be a true cherry (2 locules) as that trait is dominant to the multi-locular ones.

Great info Bower. Let me ask a couple of follow up questions. How is it that on the same plant some fruit will have 2 locules and some will have 3?
Interesting about a true cherry bring defined as 2. So a plant that produces both 2 and 3 loculed fruit
Is not a cherry?

[bower]

Originally Posted by ginger2778

Great info Bower. Let ne ask a couple of follow up questions. How is it that on the same plant some fruit will have 2 locules and some will have 3?
Interesting about a true cherry bring defined as 2. So a plant that produces both 2 and 3 lockuled fruit
Is not a cherry?

I could say I have the same question!
My Yellow Warbler (cross of Medovaya Kaplya X the Kimberley-ZK F1) also had 2 and 3 locule fruit in the F1.
I would venture to guess that has something to do with "incomplete dominance" or "penetrant" genes.
In the case of MK X KiKu F1, we know MK is a cherry with two locules only, and so every variant in the F1 has one cherry allele. You would expect them all to be two locule, if completely dominant, but was not so. I guess that contradicts what I said the first time.
Now I'm thinking through some other crosses where one parent was 100% cherry, and there were more than two locules in small fruit. So I have seen it more than once - Skipper had more than 2 locules in F1, and a couple of cherries segregated out in the F2.
So although I'm certain that I've heard many times that cherry is dominant to larger fruit...
It also seems like one or more of the 'multi-locule' genes (there are several) is what they call "penetrant". meaning it will express in a small way even though the other trait is dominant. So you get a plant with both 2 and 3 locule fruit, or in the case of Skipper, all at least 3 locules iirc.
Don't know if you will find that makes more sense or less.
Seems to me that every Mendelian assumption that I started out with, turns out to be way more complicated than I thought. Except for RL/PL and a few other 'simple' traits, it seems to be all surprises.
There are so many shape genes and modifiers, it gets way trickier in the real world when you may happen to have some odd combo of things.
Somewhere I have links or articles I collected about shape and size genetics, but not sure where to find them. There are some great articles out there with very nice pics. Maybe try a search in the crosstalk forum or a google for tomato shape genetics, tomato size genetics, tomato locule genetics....

Upshot, afaict, is that yes you should select for two locules if you want a true 'cherry', but small fruit cherry sized with multi locules are possible to stabilize too.

[ginger2778]

These are showing up in F4s. OK, now I need to do some searches. Your explanation is very helpful, do thank you for your insight, and time.

[KarenO]

I think the big flavour and unusual colours are what to select for. Small size with multi locules seem to make them meatier, less seed/gel. I dislike cherries that are all skin and seeds.
KarenO

[ginger2778]

I'm with you Karen. Luckily, every single one I have tasted has big flavor. They have that "pow"! I love them.

[bower]

I like your thinking, KarenO.
If the multilocule is still showing up in F4, maybe select for it and go for meaty.
I know I was hoping for a larger fruit selection in F2 from those "mix of 2 and 3 locule" Warblers, but 2 of 3 in the next gen were actually smaller cherries.
A new friend is growing out a larger number of the F2 this season to see what we can find.

Ultimately though I had to select on taste, color and shape and felt really lucky to get all three, no point complaining about the size. I don't think I even looked at locule number, just glad enough to get one like and as tasty as the previous.

[bower]

Ok I took a minute to go digging and here is a quote I dug out of my text file of notes. It sounds like "two to three locules" is the wild type. I seem to recall another paper with great pics though that distinguished between the classic 2-locule cherry and a 3-locule wild type.
Al Kuffa comes to mind as a three locule fruit, I thought they were soooo cute.
"Front Plant Sci. 2014 May 27;5:227. doi: 10.3389/fpls.2014.00227. eCollection 2014.
What lies beyond the eye: the molecular mechanisms regulating tomato fruit weight and shape.
van der Knaap E1, Chakrabarti M1, Chu YH1, Clevenger JP1, Illa-Berenguer E1, Huang Z1, Keyhaninejad N1, Mu Q1, Sun L1, Wang Y2, Wu S1.

"LOCULE NUMBER

LOCULE NUMBER (LC) controls the number of carpel primordia and a mutation results in a fruit with more than the typical two to three locules (Barrero et al., 2006; Munos et al., 2011). Increases in locule number often lead to a flat fruit of a larger size and the mutation is common in beefsteak tomato and tomatoes on the vine (Munos et al., 2011; Rodriguez et al., 2011) (Figure ​(Figure1C).1C). Since carpel primordia arise early in floral development, it is likely this gene functions in regulating meristem size and/or in the initiation of organ primordia.

Fasciated

The mutation in FASCIATED (f or fas) leads to increases in locule number with more pronounced effects on locule number than lc (Lippman and Tanksley, 2001). fas is found in certain heirloom tomatoes and a few commercially grown beefsteak varieties (Rodriguez et al., 2011) (Figures 1B,C).
...Significant epistatic interactions have been detected between lc and fas (Lippman and Tanksley, 2001; Barrero and Tanksley, 2004), suggesting that both genes act together by co-regulating a core pathway that controls locule number.....Because of the function of YABBY family proteins and its expression pattern, we consider that FAS is controlling the second stage of final fruit size and shape regulation by impacting meristem organization and boundary information...
In near-isogenic lines (NILs) using the wild species LA1589 as the background, the impact of these two genes on locule number is much less dramatic (Figure ​(Figure5B),5B), supporting the notion that in the cultivated background modifiers of these mutations exist. "

Anyhoo, LC and fas are the main genes that affect multi loculism.

[bower]

Here is an awesome tomato shape graphic, if the link works:

[KarenO]

That's awesome Bower, thank you so much for taking the time to post this information! Very interesting .
KarenO

[bower]

One more figure - this one has wild type = 2 locules and says that "LC" produces 3-4 locules.
Maybe there are different alleles for 3 vs 4.
Then when you add fas to LC, you get 6 or more....

https://www.researchgate.net/figure/...omestication-S

[dfollett]

Great project Karen and Marsha!

This particular topic brings me to a hypothetical question....

• I have an F2 plant from a cross of a large fruited indeterminate and a small cherry.
• The F2 fruit are all about the same size. Most have two locules and a few have 4 or 5 locules.
• Am I more likely to get larger F3 fruits from seeds out of the fruit with more seed locules?
• If I want larger fruit in the F3s, should I be separating the F3 seed based on the number of locules in the F2 fruit?
• Is the number of locules in fruit from the same plant any sort of predictor of size potential differences from individual fruit in later generations?

As if it isn't time consuming enough saving seeds now, am I going to have to start counting seed locules and saving two batches of seed from a single plant????

Interesting - and thanks for the info.

[ginger2778]

Bower, thus was a great way to start my morning. Your info is very interesting to me. I have to go back and reread it later today when I am more awake, and start googling terms, lol. You are an excellent teacher, and I really appreciate your effort.
Bower and Dfollett, so I think maybe this is busting a long held "belief" that I thought was a given: I always thought the genetics were all the exact same on any/all fruit taken from a specific plant, but if there are locule number differences does that then mean the genes may be different for those differing numbered locules?

[bower]

dfollett,
The genetics of the seeds should be the same on all fruit from the same plant. If some are multi-locule then it looks like either LC or fas is there, heterozygous with the 2 locule wild type and "penetrant" or partly expressed. Just saying anyhoo you likely have one or the other multilocule gene but not both.
So your F3 from that plant, you should find some multilocule fruited plants in a 1/4 distribution ratio not counting effects of linkages or luck.
In order to recover really large fruit though, you would need to get both LC and fas together in the line, plus there are a number of other loci governing size, many enough that you'd have to grow out a lot of plants to find them all together. This has been discussed a few times in the Crosstalk forum.
If you are looking for really large fruit, you'd be better off growing large numbers of the F2 for starters, to find one that has LC and fas and take your largest fruited F2 from there.
Or there's always the option of selecting a smaller but multilocule fruit from your F3, and backcrossing to the large parent to narrow the search for size.

[bower]

Marsha, I'm glad you find it interesting, but I'm not much of a teacher.... still trying to teach myself and obviously, still confused about LC and fas
The standard notation for genes is that dominant are written in capitals and recessive in lower case... this doesn't entirely help with additive or QTL traits but should help to iD which trait is expressed in an F1 or not...
I think I was wrong about the 'wild type' 2 locules being dominant or perhaps it is incomplete dominant or one of those other conditions that give the lie to simple Mendelian reckonings.

Here is another example from my projects: a cherry X (beef X heart F1).
The F1's are unique because of crossing unstable lines.
I selected two of them to follow - one pointy (Rodney) and one flat minibeef (Skipper).
Here is a pic of the locules in the F1: Rodney on the left has 3, Skipper on the right has five.
http://www.tomatoville.com/showpost....50&postcount=6
Since one parent is cherry, we know that both have one "two locule" allele.
Since "LC" is dominant (caps) my guess is that LC is expressed in both and the reason for having more than two locules in the F1.
Since "fas" is recessive, I should assume that it is not expressed in the F1.
If I had to guess, I would think maybe "fas" is present in the Skipper (5 locule) but the F2 results don't agree with that at all. (Rodney was the bigger of the two, but heart shape elongation could account for that).
Skipper F2 segregation produced 2/6 cherry (2 locule fruit) and 4/6 with 3-4 locules, about the same size as the F1 and no hint of anything larger from a hidden fas.
http://www.tomatoville.com/showpost....8&postcount=40
http://www.tomatoville.com/showpost....8&postcount=41
Not sure if there were any with five, I will have to check my reservoir of pix.
I only grew 4 Rodney F2's - and they all had 6 or more locule fruit.
http://www.tomatoville.com/showpost....8&postcount=42
It looks like the recessive "fas" was in the Rodney line as well as "LC", and in combination produced larger fruit. The 'hearty' elongation didn't show in four plants except as a shallow bump in one of them. Pretty sure I would get even more shapes and sizes with a more extensive F2 growout of these.
While the Skipper line seems destined to remain small and overall is closer to stability already because fewer size and shape genes were present from the start.

If that confuses the question, well... count me in on the confused.

[jmsieglaff]

One of my favorite Tville threads! Can't wait to see more this summer! Thanks for all your posts on this project!