Restoring Promiscous Pollination To Tomatoes

[steev]

Were I "sticking it to the man", I'd prefer Pacaya, an interesting vegetable; easier to "introduce", given its shape.

[nicollas]

May be of some interest
Genetic Analysis of Traits Distinguishing Outcrossing and Self-Pollinating Forms
of Currant Tomato, Lycopersicon pimpinellifolium
www.docdroid.net/sUF8KvS/333full.pdf.html

[keen101 (Biolumo / Andrew B.)]

I received my seed for a few wild tomatoes from Alan Kapuler from Peace Seeds today. While doing a quick google search this evening about "occasionally outcrossing tomatoes" i ran across this neat little paper. What caught my eye was this second paper unexpectedly also mentioning the variety 'Magnus' as being somewhat of a high outcrossing variety. The first paper i found it mentioned in (i think i mentioned it in this thread last year) i got it because it was mentioned as being the one with the most exerted stigmas. So now i'm even more excited to grow magnus. Last year it was one of the fastest and most vigerous growers in the seedling stage and is the first potato leaved tomato i've ever grown before.

Here is this new paper i found with all the cool interesting info pasted below:
libraries.uark.edu/aas/issues/1973v27/v27a8.pdf

Alexander et al. (1971) noted that "in this area (Wooster, Ohio), most if not all tomato
flowers are pollinated by bumblebees."

Lesley (1924) showed that the length of the style
was a factor in the extent of outcrossing in California: 5% for
the long styled variety Magnus. Bumblebees were seen to visit the flowers in
this experiment.

Both areas gave a maximum of 5% outcrossing
with 6-ft separations between plants. This amount decreased
with an increase in distance from the foreign pollen; no
outcrossing was seen beyond 72-90 ft.

Two factors are involved: proximity to pollen
vector and lack of competition for self fertilization. The studies
of Richardson and Alvarez (1957) eliminated the second factor;
they used a recessive leaf shape mutant rather than male
steriles to test for outcrossing. At certain times of the year 17%
outcrossing was obtained in areas near good pollinator
habitats. (The pollinator was the halictid bee, Augochloropsis
ignita Sm.) However, in some areas only 0.3% outcrossing was
found, even with plants as close as 1 m to the pollen source. In
Peru a similar study showed from 15 to 26% outcrossing (Rick,
1958).

It appears that although the stigma position, proximity of
foreign pollen, and competition of pollen from the same plant
all play a role in determining the amount of outcrossing, the
activity of the pollinators is the most important factor.
Therefore, one might expect great differences between different
areas. However, all of the studies in the United States east of
the Rocky Mountains have shown less than 5% outcrossing,
indicating uniformly low pollen vector activity.

[keen101 (Biolumo / Andrew B.)]

I have two questions.

1.are exerted stigmas dominant or recessive?

2.are peeling anthers dominant or recessive?

If i'm going to start diving into some of my own crosses i need to know which promiscuous traits are easily identified in the F1 (dominant) and which ones are only recoverable in the F2 (recessive).

[nicollas]

If you look to the doc i've given, it seems that the relevant morphological caracteristics are under several genes (QTL)

[nicollas]

This should interest you guys :

tgrc.ucdavis.edu/Data/Acc/AccDetail.aspx?AccessionNum=LA2380
LA2380
Traits: Exserted stigma from S. pimpinellifolium
Horticultural Recommendations: greenhouse culture; very slow stock

[reed]

"Alexander et al. (1971) noted that "in this area (Wooster, Ohio), most if not all tomato flowers are pollinated by bumblebees."

That's interesting, also here in various places on the forum I'v seen mention of bumblebees pollinating tomatoes but I do not see that in my garden in SE Indiana. I have seen bumblebees on tomatoes but only very late in the season when a lot of other flowers are gone and frost is imminent, way too late for any fruit to develop. Earlier in the season the bumblebees completely ignore tomatoes in favor of other things. Honey bees visit rarely but still more often than bumblebees.

I paid close attention this year and observed that several types of small sweat bees similar to the halictid bee mentioned above  were common on the tomatoes. Crossing I suspect is high especially on flowers even slightly configured for it but not by bumblebees.

[Joseph Lofthouse]

The exerted stigma trait seems more like a QTL: In my crosses between domestic tomatoes and S. habrochaites, the styles are exerted, but not as much as in S. habrochaites. So partially dominant. I haven't measured if the effect is due to styles being longer, or anthers being shorter, or some combination, etc.

I haven't recovered the "non-connected" anthers trait that I was looking for in one of my crosses. I only planted about 32 F2 plants.

Huge petals seems to be a dominant trait. (Stabilizing dominant traits sucks!)

The beefsteak type flower trait seems to be recessive.

[Joseph Lofthouse]

Here's what some of the tomato flowers looked like today. These are F1 plants of a cross between Fern, my earliest red slicing tomato, and LA1777, solanum habrochaites.





In other news, I have an F2 plant from the panamorous tomato project that is just forming flower buds, so it looks like there is plenty of time for it to make seeds before I want to be starting the spring tomatoes.

[keen101 (Biolumo / Andrew B.)]

WOW! Keep up the good work!

a related question... domestic tomatoes are recommended to be started 6 weeks before planting out, i think. In your experience when should one start wild tomato species? From my feeble attempt last year the wild seedlings seemed to grow much slower than domestic, so if that has also been your experience i assume it would be good to start them earlier?

I've been having great success with my new LED grow lights these past few weeks during winter, and my experimental tomato seedlings are doing very well and the leaves are not yellow this time and are dark green. (http://www.banggood.com/100W-1131-Red-234-Blue-LED-Grow-Light-Plant-Lamp-Garden-Greenhouse-Plant-Seedling-Light-p-1020547.html) So I feel confident in trying my hand at all those tomato seedlings again this year.

[Joseph Lofthouse]

Keen101: The wild tomatoes can be slow to germinate, and they start out small, so adding a couple extra weeks seems fine.

I didn't record dates when I planted these. They are more or less the same age, about 2 weeks. From left to right: 25%:75% Domestic:habrochaites, S. habrochaites, S. peruvianum. Perhaps I'll start a side-by-side test.



And since I had my camera in the grow box, one of the F2 plants of a cross between domestic tomatoes and S. habrochaites is getting ready to flower. It's been 7 weeks since I planted the seeds. Growing conditions are 82F day and night with 12 hours of fluorescent light per day. Looks like there is plenty of time to grow one more generation of seed before spring.

F2: [2.5" red X LA1777]

[keen101 (Biolumo / Andrew B.)]

ok. thanks! That's what i was kindof thinking already.

p.s. i found this gem of a photo today! (source: www.irbtomato.org)



I will try to grow out some S. galapagense this year. I will try and see if the flowers are as noticeable as the ones in this image. S. huaylasense and S. corneliomulleri look interesting.

[ferdzy]

keen101 (Biolumo / Andrew B.), there's a stray bracket at the end of your link so it doesn't work.

And I have to laugh; what struck me when I got through to the site is they are using those little nylon organza party-favour bags from the dollar store that I also use to keep flowers from crossing with something unwanted; so handy.

And yes, that's a great picture. I've never heard of half those things. Are they all edible? ("edible"?)

[Joseph Lofthouse]

Today I received one of my two seed purchases for the year. It was wild tomatoes from Peace Seeds.

Solanum peruvianum
Solanum habrochaites, v typicum

Solanum lycopersicum, Golden Tressette Tomato
A beautiful indeterminate original cultivar with clusters of orange cherry sized fruits of unique and excellent flavor. The flowering clusters generally have 20-40 fruits per tress. This new cultivar has both Solanum pimpinellifolium and Solanum chilense in its ancestry.

The other purchase contains cactus seeds and Solanum chilense from Sacred Succulents.

[Joseph Lofthouse]

Last year I had zero jermination on about 8 accessions each of S. galapagense and S. cheesmanii. Tonight I pooled the remaining seed from each species, and planted them into a single pot for each species. I figure that way, if nothing jerminates that at least it's not taking up so much room.

I also changed the configuration of the jermination chamber to be about 83F/65F day/night.