Leaf shape and heat tolerance

[J Peazy]

What if any role does leaf shape play in heat tolerance/humidity tolerance.

Is a plant with a serrated leaf more heat tolerant than one without? Most of the commercial heat-set hybrid tomatoes seem to have a serrated leaf - is this coincidence.

What about the broadness and length of the leaves? Do these factor in?

Anecdotally, I looked up leaf types from desert plants and rainforest plants and noticed that desert leaves tend to be small and tropical leaves tend to be broad with deep serrations. A broad leaf would aspirate too much in the desert, right?

Thanks in advance.

[Tracydr]

Striped roman is a witty leaf tomato. It always looks silty but produced well in the heat for me last year. I do use shade cover to protect from sun scald.

[Elizabeth]

As I was deciding what varieties to plant last fall I noticed that there seemed to be a higher percentage of potato leaves in cool tolerant varieties than in tomatoes in general. Just an observation based on the almost 250 varieties I have seeds for - nothing scientific or comprehensive about it. I purposely bought a number of varieties that have cool tolerance, and the leaf type didn't play into purchasing decisions, it's just how it came out. In my seeds 10 of 33 cool tolerant are PL and 18 out 202 regular season ones I have are PL. It definitely seems skewed. I don't have seeds for varieties specially bred for heat since it's not an issue for me, so I don't have any observations for heat tolerant varieties.

[Tom Wagner]

Interesting that leaf type was brought up as a link to heat resistance. Also interesting that Striped Roman mentioned...since one of the parents is my Banana Legs from the 1970's breeding and selection work I did in Kansas....which can be quite hot during July and August.

I am in the cool PNW...where heat tolerance would be an oxymoron. But my many years in California breeding tomatoes to take the heat near the Salton Sea and through much of the central valley...San Joaquin....yes....leaf type, density, indeterminate, determinate, maturity, etc., all play a role.

Wrong time of year for me to explain...too busy filling seed orders from my website and yet to sow any of my own seed. Maybe I can bring up limited examples a bit later.

I made videos of potato varieties that took the heat some twenty five years ago...and could write about that on the potato forum someday, too.

Tom

[J Peazy]

Originally Posted by Elizabeth

As I was deciding what varieties to plant last fall I noticed that there seemed to be a higher percentage of potato leaves in cool tolerant varieties than in tomatoes in general. Just an observation based on the almost 250 varieties I have seeds for - nothing scientific or comprehensive about it. I purposely bought a number of varieties that have cool tolerance, and the leaf type didn't play into purchasing decisions, it's just how it came out. In my seeds 10 of 33 cool tolerant are PL and 18 out 202 regular season ones I have are PL. It definitely seems skewed. I don't have seeds for varieties specially bred for heat since it's not an issue for me, so I don't have any observations for heat tolerant varieties.

I wonder what the evolutionary benefit of variegated foliage is? Would the white part of the leaf reflect more sunlight?

[J Peazy]

Originally Posted by Tom Wagner

Interesting that leaf type was brought up as a link to heat resistance. Also interesting that Striped Roman mentioned...since one of the parents is my Banana Legs from the 1970's breeding and selection work I did in Kansas....which can be quite hot during July and August.

I am in the cool PNW...where heat tolerance would be an oxymoron. But my many years in California breeding tomatoes to take the heat near the Salton Sea and through much of the central valley...San Joaquin....yes....leaf type, density, indeterminate, determinate, maturity, etc., all play a role.

Wrong time of year for me to explain...too busy filling seed orders from my website and yet to sow any of my own seed. Maybe I can bring up limited examples a bit later.

I made videos of potato varieties that took the heat some twenty five years ago...and could write about that on the potato forum someday, too.

Tom

Tom,

I had hoped you would reply to this thread.

I can only imagine how busy you must be this time of year. I look forward to your insight when/if you get the opportunity.

Thanks

[Tom Wagner]

Florida comes up most often when one Googles heat tolerance tomatoes.

The hybrids Tribeca, pictured below, and Equinox are noted examples of the Florida breeding success for heat tolerance.



Whether or not leaf shape is a primary or secondary factor regarding heat tolerance...one could use the Florida lines as parents in further breeding work as I have and test the results as hybrids and/or segregating lines. Again, I am in a area not needing heat resistance, but I may consider releasing some supposed heat tolerance segregations next year.

I will have to research my own results and tie it in with what I can find on the Internet as to leaf type....curious to know if simple leaf (potato leaf) to compound leaves are useful tools of morphology. I am still looking at blue foliage pigments as a precursor to a hypothesis of sun (heat) tolerance ....

Anthocyanin pigments are blue, red and purple. They are crucial to plants' survival. These pigments protect plants from ultraviolet and blue-green light and thus shield plants' DNA from sun damage/light stress.

Xanthophylls are yellow pigments in a group called carotenoids, which also consist of orange and red pigments. Xanthophylls are actively involved in photosynthesis along with chlorophyll. Xanthophylls, also known as accessory pigments, capture specific sunlight wavelengths that chlorophylls do not absorb

....plants actually go through a xanthophyll cycle, which allows them to transform pigments that do not quench energy into ones that are capable of doing so to protect themselves from absorbing too much light.

Read more: Which Pigments Are Most Crucial to Plant Survival? | eHow.com http://www.ehow.com/list_7559068_pig...#ixzz1qNhPFSwD

The blue and yellow pigments seems to be outstanding tools to promote heat tolerance in my potato breeding work...and that positive correlation leads me to think about tomatoes with foliage pigmentation. My Skagit Valley Gold potato has distinct yellow pigmentation in the foliage and my blue potatoes (Black Irish) etc., have a high anthocyanin pigmentation. Both of these potatoes derive in part from high elevation (Andes) countries.

Conclusion...I will have to search for yellow pigment tomato cultivars within the leaves...but my extensive blue tomato work combined with the Florida lines would be a good place for me to start. Hint..hint...competitors welcomed.

[J Peazy]

Conclusion...I will have to search for yellow pigment tomato cultivars within the leaves...but my extensive blue tomato work combined with the Florida lines would be a good place for me to start. Hint..hint...competitors welcomed.

Does a variety such as Caro Rich fit the bill for yellow pigment? Are the high beta carotene levels present in the foliage as well as the fruit?



My interest in the subject is based on my own disappointment in the performance of tomatoes in my area. By late July they are done. Last year I began looking up (Southern) university field-production trials and certain names kept showing up.

A few include:
Bella Rosa - which I understand has some Florida lineage
Valley Girl
Phoenix
Talladega

These all seem to produce large yields of fruit under the same types of conditions we experience here in the summer.

I am a complete novice, but I purchased Bella Rosa and Sun King seeds in the hopes of crossing the two at some point.

I also have a tomato that I grew out from a grocery store Roma. With the help of some of the nice folks on this website it was identified as a Mexican field production tomato. The fruit is small, but it doesn't quit all summer - and at one point we had a couple weeks of consecutive 100+ degree temperatures. The leaves on it seem odd to me - though I have limited experience. The stem is also quite fibrous and needs little support.

http://www.tomatoville.com/showthread.php?t=18488

The thread will show my Septoria problems. I overwatered, and the taste of the fruit from this plant improved greatly once I corrected that problem. I tend to think it would have been quite drought tolerant as well.

[Tom Wagner]

Like I said earlier, my experience with potato breeding is greater than my tomato breeding, although I have quite a bit of trial and error there too. I don't know of any linkage of foliar coloration and fruit color as regards yellow/orange tomatoes.

If I would take the time to ask someone at the Gene Bank at Davis, Califonia....they might know. I am afraid most of the leaf mutations would be detrimental to the overall growth of the tomato plant.

[Fusion_power]

In my experience, leaf shape has relatively little to do with heat tolerance. But the reason is because most of the heat related problems are from pollination failure.

The heat tolerant lines that have been developed up to this point are able to pollinate and set fruit at temps of @96 degrees. This compares to ordinary varieties which get into trouble @92 degrees. That is not much of a difference. I have not dug around to find them, but there are wild species that live in hot climates and should be able to set fruit at high temperatures and humidity. There is ongoing work to improve heat tolerance. One variety I have grown is Nagcarlang.

Another part of heat tolerance is plants with dense leaf cover are better at avoiding sunscald. There are commercial varieties that were developed specifically for this trait. We could talk about the difference between the open pollinated line named Shady Lady in Australia vs the commercial hybrid Shady Lady that was grown for years in California. The Aussie variety was selected for tolerance to shady conditions, as in it would produce a crop even if shaded part of the day by trees. The best I recall, the California hybrid was developed to produce leaf cover that would prevent sunscald on the fruit.

I have had my greenhouse up to 123 degrees on a hot sunny day with the door closed. This does not hurt the seedlings, in fact, it seems to encourage them to grow faster.

As long as a tomato plant has plenty of water, it can tolerate the temperatures we normally experience which in my area is usually 3 weeks or so above 105 and a few days that hit 110. But if you don't water them..... They are toast!

DarJones

[chiefbeaz]

Hi J Peacy, I saw you post and am wondering what part of Tennessee you live in? I live in middle ,Tennessee {Lebanon area} and my tomatoes don't start kicking in good to mid July and most last into October unless the weather turns cool early. They do real good through most of September and then begin to taper off. I try to get my plant's in late April or early May.

[travis]

Originally Posted by Tom Wagner

Conclusion...I will have to search for yellow pigment tomato cultivars within the leaves...but my extensive blue tomato work combined with the Florida lines would be a good place for me to start. Hint..hint...competitors welcomed.

Challenge accepted!

I have been working with Florida lines, as well as lines from University of Missouri and my own yellow leaf lines since 2008.

I agree the IFAS lines set fruit up to 96 - 98F degree daytime temperatures, but so did the Missou lines, especially one that was outcrossed to Sioux. More recently, I have outcrossed both the IFAS and the Missouri lines to a couple of NCSU lines to increase fruit size while trying to maintain heat tolerance.

Everything I am carrying forward this year is regular leaf, so I cannot really comment on potato leaf except to say Spudakee has been the only potato leaf variety I grow tha comes close to matching the fruit set capabilities I've exampled.

Another source of good heat setters has been the University of Arkansas lines such as Bradley, and the two Travelers.

The yellow leaf lines were not as heat tolerant as the Florida and Missouri outcrossed lines with regard to fruit set. And while their foliage survived temperatures up to 105F with high sun conditions, they did shut down growth a bit, and the leaves lost noticeably their vibrantly bright appearance.

There are four or five individual genes that can be involved in light leaf expressions, and I do not know for sure which ones are present in the lines I'm working with, except to say it appears the most fragile plants are those in which no anthocyanin is present in any part of the plant.

I cannot comment on the "blue" tomatoes because I don't use the anthocyanin types from OSU due to reasons of low or negative flavor issues.

[J Peazy]

Challenge accepted!

I hope you all decide to share your progress and results here. I am eager to see what you come up with.

[J Peazy]

Originally Posted by chiefbeaz

Hi J Peacy, I saw you post and am wondering what part of Tennessee you live in? I live in middle ,Tennessee {Lebanon area} and my tomatoes don't start kicking in good to mid July and most last into October unless the weather turns cool early. They do real good through most of September and then begin to taper off. I try to get my plant's in late April or early May.

I'm in La Vergne. What varieties are you growing?

[Tracydr]

If you look to desert plants adapted to heat and high temperatures, many have little or no leaves to prevent water loss. Perhaps, in the desert heat of Phoenix, that is why Striped Roman did well? The wilty leaf has less surface area?