Micro dwarf x Indeterminate cross ideas.

[KaguyaCloud]

Curious of what kind of grow lights you use?? I’ve been up and down with mine

I settled with relatively mid ranged Monios T8 2ft grow lights from Amazon that are about 24 watts per light(6 pack is $60-80 depending on sale). Any 2ft white LED bar lights that use about 24 watts per individual light will do, no need to use anything expensive. The lights effectively cover a 22 inch by 3 inch area if you plan on growing tomatoes. Space the lights 1-3 inches above the foliage of the plant for maximum amount of concentrated light. I also use a digital timer on the outlet that turns the lights on for 15 hours every single day.

[KaguyaCloud]

I think my first step is going to be acquire and grow out every compact dwarf variety I can get my hands on, and play around with stunting larger cultivars. I'll probably mirror your cultivation methods (which I see as something of a crossbreed that might already yield most of the benefits of hydro cultivation) but I'll also probably rig up a few simple systems to compare results. I've read about good results flavor wise by moving plants to 'soil' for fruiting, so that'll be something to explore as well.

Just out of curiosity what are your goals in breeding these tomatoes?

Stunting large varieties for me has been quite a bit of a challenge. 4 inch pots can grow really large tomato plants if you give them enough nutrients and light. It's possible that the best way to stunt them is the use 2 inch cells, but watering them may be a large hassle to do. My cultivation method is a standard soilless set up with consistent hydroponic fertilization as a technique. It's basically a modified Bruce Bugbee cultivation method with coconut coir and perlite as the planting media. You water the pot with nutrient solution until 10% leaches out, measure the nutrient levels with a regular ppm or EC meter, then water with tap or dilute hydroponic nutrients depending on the nutrient levels.

When growing in very small containers, there will never be enough nutrients in the media to support a growing and fruiting plant, which is why the hydroponic nutrients are there to feed them. If you would like, I can give you extreme details on exactly what I have done and have bought.

[AKgardener]

@KaguyaCloud thank you I grow pretty much all micro during the winter so I’m always looking for what others use ..

[Lisaliza]

Just out of curiosity what are your goals in breeding these tomatoes?

Boy, I wish I could answer that with any measure of confidence! The most honest answer is that I'm doing this to move on from my new obsession - my hands are tied, I have to run with it until I achieve some level of mastery or become bored. The latter is, of course, more likely.

I'm sure that's not the kind of goal you were looking for, though! I don't have a particular plant/fruit combo in mind at all, my goal is much more nebulous. It boils down to an interest in optimizing home/local food production - maximum (supermarket quality or better) yield for minimum inputs. In my mind, time spent on labor is the most expensive of all inputs, followed by space (indoors, volume) and elapsed time. At this stage, I'm taking that to mean high yielding compact plants whose needs can be mostly automated, with as much resistance / tolerance / nonspecific diversity as I can manage to cram in. Past that, I have no idea where I'm heading. I'm very intrigued by concepts like landrace gardening and promiscuity, and I have some fuzzy vision of developing my own 'master parent' lines for amateur use. In the end, I'll likely settle for just having learned something new - but you never know, maybe I've finally found the thing that stays interesting forever.


Re: stunting, I'm really only interested in it as a means to an end - the 'wild' types whose genes I'm interested in tend to be massive, and it would just be nice if I could keep the whole project at home in the no-pants zone.

If you would like, I can give you extreme details on exactly what I have done and have bought.

I will almost definitely take you up on that when I've moved on from the seedstock portion of the buying spree! There are so many components I have yet to even consider. Many of the cultivars I'm particularly interested in don't appear to be available in the US, so I have to get those orders placed and start the clock on that.

[KaguyaCloud]

Update 8/28/24:


The right Joro F2 plant has begun to ripen. Lots of fruit has started growing. It has been 53 active growing days since the initial planting(55 days minus 2 days without power).

Left F2: Exhibits indeterminate growth habit. Heavy fruit set. I've noticed that the amount of pollen that the flowers of this plant is significantly more than the right F2, which is likely attributed to the Micro parent Jochalos. I've noticed that the smallest micro dwarfs exhibit much more pollen shedding when shaking the flowers compared to the indeterminate cherries I have been growing.

Right F2: Exhibits micro-like growth habit. Despite having many more flowers, it seems that the right F2 has lower fruit set. However, it looks like it is setting fruit in layers at a time like the indeterminate parent Rosella Cherry. The flowers that have yet to develop fruit have very stiff joints, which should be an indication of some-what successful pollination. In addition, it apparently has the uneven ripening gene pattern from Rosella Cherry. Rosella Cherry's fruit set has green shoulders at around the base of the sepal region, but does not spread out further more than that. The leaves do not seem to exhibit the leaflet reduction gene, as some grew to be extremely large compared to the micro parent.

Overall, this is pretty exciting to see. It looks like my growing conditions make it so that 55 days is the average from open cotyledons to the breaker stage of the fruit. I expect another 7 days for the fruit to turn color and then another 2-3 weeks for the fruits to fully ripen on the vine. If I am impatient, I could pick the fruits once it has turned its final color, but what would be the point of doing that when I'm selecting for flavor?

Assuming maximum amount of sweetness and flavor of the fruit itself, the timeline of a full generation is as follows:
Germination to open cotyledons: 7 days
Open cotyledons to first flower: 27 days
First flower to first blush: 28 days
First blush to final color: 10 days
Final color to full ripening: 14-21 days
Seed collecting, drying, freezing: 7 days.

Maximum range per generation: 93-100 days.

At a leisurely pace, I can breed a generation every 100 days, which would be 3.7 generations per year. However, if the flavor is well preserved, I could start seed collecting at final color instead of full ripening. This would shorten it down to 79 days or 4.6 generations per year. I wonder how many generations would it take for good flavor to be well established.

[bower]

I love the loaded truss on the plant on the left!
Interesting it appears shorter than the other, even if it is an indeterminate pattern.
Both are certainly compact enough to be well suited to the indoor environment, and still producing fruit quite early.

[Doffer]

I think u can collect seeds at blush stage. This will shorten to 69 days.
When u do the tatse test at full ripening u only ceep the seedslings from the best plant. And give them a bigher pot.

[KaguyaCloud]

Mapping fruit color traits:

Based off the ripening behavior of the rightmost Joro F2, it seems to have a very pale yellow color. It's possible that it may be yellow/white tomato. I wonder what are the possible homozygous genetic combinations and colors that could arise from these sets of genes. Here are the potential genotypes of the fruit traits:

Rosella: Clear skin(yy), red flesh(RR), green flesh(gg), uneven ripening(UU). This leads to a dark burgundy colored tomato with green shoulders.

Jochalos: Yellow skin(YY), low lycopene flesh(rr), no green flesh(GG), uniform ripening(uu). This leads to a yellow colored tomato. Although, the skins do eventually turn orange.

Joro F1: Yellow skin(Yy), red flesh(Rr), no green flesh(Gg), uneven ripening(Uu). This leads to a red colored tomato with green shoulders.

Potential colors of the F2(Skin ; Flesh color 1; Flesh color 2):
YY, RR, GG: Typical red tomato (yellow skin + red flesh)
YY, RR, gg: Brown tomato (yellow skin + red flesh + green flesh)
YY, rr, GG: Yellow/Orange tomato(yellow skin + yellow flesh)
YY, rr, gg: Yellow-green tomato(yellow skin + yellow flesh + green flesh)
yy, RR, GG: Pink tomato (clear skin + red flesh)
yy, RR, gg: Burgundy red tomato(clear skin + red flesh + green flesh)
yy, rr, GG: White/Pale yellow tomato(clear skin + yellow flesh)
yy, rr, gg: Pale yellow-green tomato(clear skin + yellow flesh + green flesh)

Well, that's quite a few color combinations for sure. I had zero intention of having such a large spectrum to work with.

[Doffer]

Ad the Uu genes and u have even more combinations.

[bower]

Ad the Uu genes and u have even more combinations.

What happens with them @Doffer ? I've noticed that some F2's have varying amounts of green shoulder, although not sure if uu was in the parentage. Are there QTL's involved in green shoulder expression?

[KaguyaCloud]

I assume that it means there are even more phenotypes, so that list would be twice as large with each half getting either uniform ripening or green shoulders.

I've noticed that some F2's have varying amounts of green shoulder, although not sure if uu was in the parentage. Are there QTL's involved in green shoulder expression?

Based off of my personal experience, it seems that there definitely is something affecting the levels of green shoulders in the F1 and F2. And whatever it may be, it seems recessive. Rosella Cherry has the green shoulder genes, but it seems very suppressed and only covers just the top 1/8th of the tomato.

The F1 has green shoulders that covers up to 1/3 of the fruit. However, the smaller shoulders came back in the F2. Because the one parent has the uniform ripening gene and that larger shoulders are dominant in the F1, it's guaranteed that there seems to be some recessive gene that represses green shoulders coming from Rosella.

We could eliminate several potential chromosomes since certain recessive traits from the micro parent have replaced the indeterminate parent: dwarf gene, yellow flesh, determinate(?).

All I can really do is hypothesize things such as a spherical fruit shape and long sepals as potential links, but those could be coincidences from the gene shuffle in the F2.

[KaguyaCloud]

Update 9/3/24:
It seems that the Joro F2 Right fruit has fully ripened, as it is very soft to the touch despite the ghostly yellow color. Joro F2 left is beginning to ripen.


Unfortunately, there were zero seeds in the first fruit despite being the largest fruit on the plant. Crossing my fingers to at least get one seed from this line. I did notice that the flowers on the right F2 did not shed much, if not any pollen at all. Early flowers also exhibit exerted styles. It likely obtained this nearly seedless trait from the indeterminate parent, Rosella Cherry. Is this parthenocarpy?

Fruit structure is very meaty, exactly as meaty as Rosella Cherry in fact. Skin color is very clear, meaning it does have the clear skin gene, like in Rosella Cherry. The gel inside is a clear color.

While there's is flavor from the right F2 reminiscent of Rosella, the intensity of the flavor is very diluted. There's also no sweetness or sourness to the fruit either, making it quite watery. I may need to wait longer, however I feel that it might become very mushy by then.

If the next fruit does not have any flavor to it at all, I will likely save a few seeds and note it down as a dead end in terms of flavor genetics, which is a shame considering that it has the early termination gene. On the upside, it seems that flavor seems to segregate independently from fruit shape, fruit internal structure, and leaf shape.

Now that I know that I could potentially have bland tomatoes despite all those Rosella phenotypes being expressed, I might get aggressive in the culling on my next F2 growing trials or hoping on the left F2 to have some flavorful genes in it.

[bower]

Taste certainly does segregate independently from other fruit traits - 'taste' is such a complex trait that many QTLs are involved. If the parents are divergent at all in taste qualities, you can continue to get different tasting tomatoes right to F7. So don't write off the line at this stage where you've only selected for growth habit. If you don't get good taste in the next generation, you would probably be best to focus on other lines.
Last season I had a F3 GWR bicolor that was selected for determinate growth habit. The taste was not exceptional, but I grew two plants this season anyway for some disease resistance comparisons. Shockingly both of these plants have outstanding fruit taste this season, and top rated even compared to my favorites. Possibly the taste genetics was there but simply wasn't well expressed due to less optimal growing conditions last year. Or it could be that I just lucked out, and picked two seeds that had a higher Brix combination of alleles, and that brought out the taste complexity. So although it's generally not advised to select away from taste, I'd give it a second generation to express that, or at least save some seeds for a rainy day to check it out. You may also find that later fruit taste different, although IDK since your conditions are so controlled, how much variation there might be on the plant.
The ability to set without pollinated seeds is parthenocarpy, indeed. It's more common than advertised, at least, you can find plants in the general body of OP's/heirlooms that will do that in some conditions, although more commonly the unseeded fruit are smaller than normal, and not larger. It would be unusual to have all unseeded fruit on a plant though.

[KaguyaCloud]

The parents are indeed very divergent in flavor. I crossed a fruity, sweet, and low acid indeterminate with a neutral flavor, slightly acidic micro. In terms of growing conditions, the two F1 plants that I originally grew tasted exactly the same while being grown in the same set up, so there shouldn't be too much variation in flavor and sweetness at the very least. However, I am going to wait to see if any additional sweetness pops up the longer it is attached on the vine before making anything conclusive. If it turns out to still be not great, I will save seeds and continue to start growing the other 2000 F2 seeds that I have collected. There's so much potential for flavor if I can start over.