Author Topic: Short day length maize and other curly questions  (Read 384 times)

Steve1

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Short day length maize and other curly questions
« on: 2019-04-23, 06:30:26 AM »
Hi all, I've been doing some maize crosses over summer (and am still working on some at the moment) and have managed some short day maize crosses to Painted Mountain x sweet F1 and Glass Gem. Does anyone have any insight into the genetic control of short day length in maize? Did your F1's, F2's display this short day trait or was there segregatiion?

Secondly, the cooking time of flints for polenta - does anyone understand what makes a flint corn cook more quickly? Is it more flinty endosperm or another factor entirely? Any thoughts appreciated.

Cheers
Steve
 

Joseph Lofthouse

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Re: Short day length maize and other curly questions
« Reply #1 on: 2019-04-23, 01:04:25 PM »

I'll spout off on this topic, based merely on my own experience with corn, without much awareness of whatever the research might say....

It seems to me, like days-to-maturity and day-length-sensitivity are traits that are controlled by different sets of genes. And that they are not closely correlated with each other.

When crossing temperate (non-tropical) corns with each other, I haven't seen any reversion to day-length-sensitivity  regardless of which parents were used. Days-to-maturity seems to be a complex trait controlled by many genes, so I don't observe distinct segregation among the offspring. It's more like a blending of parental traits, with many intermediate types all jumbled together. I find days-to-maturity to be readily heritable, so it's an easy mass-selection project to select for earlier/later types.

I haven't been able to successfully make any crosses between temperate and tropical corns, so I don't have a clue about how the crosses would segregate. If day-length-sensitivity is a singe allele trait, then it would be simple to select among the F2 for long-day-flowering.

Here's some reading material on this topic...
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3396540/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2845347/ indicates that 40% of photo-period-sensitivity was due to one QTL.

reed

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Re: Short day length maize and other curly questions
« Reply #2 on: 2019-04-23, 06:26:14 PM »
Days to maturity has been an unreliable indicator for me. It gives a general guess where one say that is described as 120 days compared to one described as 100 days but heat units is what determines maturity. If I grow two patches of the same corn, one planted late April, one planted early June the late planted one matures in fewer days.
{add} O, I just though the one planted in April spends a lot more of it's life in lengthening days where the June planted spends more in shortening days,  hmmm
 
That said there might be something to the day length as well. When I attempted to grow Zea perennis it got huge but did not flower. However when I grow  the descendants of Zea perennis / zea mays  hybrids they follow the same pattern as first described.

*on  a side note not to hijack the thread I am not 100% certain at this point that my Zea perennis plant died over winter as I expected it would. If it is dead it sure isn't at all decayed, I can't pull up even a small shoot.
« Last Edit: 2019-04-23, 06:28:52 PM by reed »

Joseph Lofthouse

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Re: Short day length maize and other curly questions
« Reply #3 on: 2019-04-24, 09:59:25 AM »
I agree with Reed's assessment. It would have been more accurate for me to write about Growing Degree Days than Days To Maturity.


Carol Deppe

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Re: Short day length maize and other curly questions
« Reply #4 on: 2019-04-25, 10:00:10 PM »
Secondly, the cooking time of flints for polenta - does anyone understand what makes a flint corn cook more quickly? Is it more flinty endosperm or another factor entirely? Any thoughts appreciated.
I've done a lot of cooking trials and taste tests on flints as polentas. There's several pages on flints and cooking with flints in The Resilient Gardener Here's the basic generalization I came up with: the flinty part of the corn kernel cooks well in response to boiling or steaming. The floury part actually does not cook at all when boiled or steamed; it requires baking.

I classify flints into what I somewhat arbitrarily call "true" flints, which make great polenta and johnnycakes, and everything else, which doesn't. The true flints all have extreme flint character--very high proportion of flint, very tiny amount of flour, and the flour itself seems to have a different texture. They are best cooked by boiling with 3X as much water, by volume, as coarse-ground corn (with some fat of some sort and salt). They will cook completely with 7 minutes of boiling with stirring followed by 45 minutes of sitting in the covered pot. They do not require additional baking. Here are the varieties of these fast-cooking flints that I know, starting with those I've bred myself: Cascade Ruby-Gold Flint, Cascade Cream-Cap Flint, Landmark Flint (parentage is Cascade Ruby-Gold and Longfellow), Abenaki/Roy's Calais flint, Byron flint, Longfellow flint, Narragansett Indian Flint, Rhode Island Whitecap. These all make great-tasting cornbread, too. If you want them to hold together without adding wheat flour or an artificial binder such as xanthan gum, you add boiling water to part of the cornmeal to make a sort of glue, then add the eggs and the rest of the cornmeal (containing the baking powder). (See The Resilient Gardener.

Good polenta flint corns require not just the true flint type, but also pericarps that are delicate and tasty. (Some varieties have pericarps that are thick and are like eating a mix of grain and wood. and some pericarps have bad flavors.) It also helps if the attachment of the kernel and cob is small instead of huge. The latter also gives polenta with unappetizing chunks of wood in it. (Varieties that were traditionally nixtamalized, which involves removing the skins, can have really bad flavored pericarps.)(With these true flint varieties, if you nixtamalize, you can simply rinse after the alkali treatment and leave skins on, since they are delicate and taste good. That cuts out the laborious rubbing step.)

To make polenta with these true flints, I use 2 cups of coarse-ground meal (biggest pieces no larger than 4 mm), 4 TBS butter, 1/2 teaspoon salt. I bring water, butter, salt to a boil, dump in meal, whisk in if needed. Turn down heat. After it comes back to boiling I cook with stirring for 7 minutes, timed. Then let it sit in covered pot 45 minutes or more. Then I stir it and eat some and pour the rest into bread baking pans and cover with aluminum foil. After it cooks I refrigerate it for use on subsequent days. If I want an especially creamy polenta and have the time, I'll put the pot in a 250 degree F oven for an hour after the 7 minute boil step instead of letting it sit. But usually I just let it sit and eat some.

All other flint varieties I've tried have a higher portion of floury endosperm, require 4 cups or more of water per cup meal, and don't taste good after the fast cooking process. They always taste a little raw. In fact, if you get used to polentas made with true flints, no other polenta tastes very good, no matter how long you boil and bake it.

All multicolored "Indian" flints I've tried are not true flints and don't cook quick. And they weren't what the Indians ate either, not as boiled mush at least. They seem to have been eating pure-color varieties. Varieties with a mix of kernel types (flint, floury, dent) are, in my experience, never good polenta corns.

Most flints that are not true flint types require boiling with stirring for 45 minutes or more, and then baking in layers in baking pans for an hour or more. If you just boil them, they will always taste a bit raw, with the amount of raw taste proportional to the amount of floury endosperm.

Commercial flints are often/usually not true flints. In fact often they are dents, ground, with the flour blown away by fans during processing. But a lot of flour sticks to the flinty bits, so there is always a raw taste if you try to cook commercial polenta made from commercial dent corn with just boiling.

« Last Edit: 2019-04-25, 10:09:20 PM by Carol Deppe »

Steve1

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Re: Short day length maize and other curly questions
« Reply #5 on: 2019-05-01, 05:47:44 AM »
Sorry have been a bit busy for the last week - but thanks Joseph, Reed and Carol for your thoughts.
Those QTL papers were interesting Joseph, and certainly pointed to a number of genes influencing daylight sensitivity. Interesting too, that in one paper they attributed 40% of the effect to one QTL.
I found this paper on teosinte x maize photosensitivity from (1950). My guess is that its probably relevant as the source of photosensitivity genes in most tropical maize. It's probably of interest to you Reed. 
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1209498/pdf/513.pdf

It appears to me from the graphs there was significant variation in the photoperiod response of the F1 and F2 depending on the type of teosinte used (which makes sense seeing some types of teosinte flowered between 105 days and 204 days).
The good news is the crosses showed much shorter times to flowering in the F1 than the teosinte parent (50-110 days), which should make it workable. The F2 was more complex sometimes with an early peak, sometimes not. That is still workable though.

On to the flint cooking characteristics, thankyou Carol for your thoughts and time. I have read The Resilient Gardener, and had noted your explanation of how the different flint / flour parts of the endosperm cook. What I hadn't grasped or understood was the quick cooking maize was an extreme flint in association with the soft pericarp and kernal attachment.
In Australia I have only come across Glass Gem as an extreme flint. Everything else is at least as much flour as flint. Unfortunately I don't think any of your flints have been imported (and lets just say its not easy), and I've dredged the Australian Grains Genebank database and not flound any of those Indian corn flints you mentioned.

I have somewhere to work from though now. I think I'll be mixing up a large bucket of water and sugar come spring, get the specific gravity to the flint / extreme flint scale and see what sinks.
I had been toying with bucket testing a large sample of Painted Mountain for rogue flint genetics - has anyone struck any flint in their Painted Mountain? 




Olaf Nurlif

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Re: Short day length maize and other curly questions
« Reply #6 on: 2019-05-03, 02:56:48 PM »
Good polenta flint corns require not just the true flint type, but also pericarps that are delicate and tasty. (Some varieties have pericarps that are thick and are like eating a mix of grain and wood. and some pericarps have bad flavors.) It also helps if the attachment of the kernel and cob is small instead of huge. The latter also gives polenta with unappetizing chunks of wood in it. (Varieties that were traditionally nixtamalized, which involves removing the skins, can have really bad flavored pericarps.)(With these true flint varieties, if you nixtamalize, you can simply rinse after the alkali treatment and leave skins on, since they are delicate and taste good. That cuts out the laborious rubbing step.)

To make polenta with these true flints, I use 2 cups of coarse-ground meal (biggest pieces no larger than 4 mm), 4 TBS butter, 1/2 teaspoon salt. I bring water, butter, salt to a boil, dump in meal, whisk in if needed. Turn down heat. After it comes back to boiling I cook with stirring for 7 minutes, timed. Then let it sit in covered pot 45 minutes or more. Then I stir it and eat some and pour the rest into bread baking pans and cover with aluminum foil. After it cooks I refrigerate it for use on subsequent days. If I want an especially creamy polenta and have the time, I'll put the pot in a 250 degree F oven for an hour after the 7 minute boil step instead of letting it sit. But usually I just let it sit and eat some.

Most flints that are not true flint types require boiling with stirring for 45 minutes or more, and then baking in layers in baking pans for an hour or more. If you just boil them, they will always taste a bit raw, with the amount of raw taste proportional to the amount of floury endosperm.

I think the flint/cooking issue may be even more complex..
I am pretty sure that there are at least two types of the flinty endosperm.
Well, it probably is a continuum, depending upon the starch types involved. I will so some research this winter!
(I also cannot totally rule out environmental influences although the varieties I will describe were grown on the same soil over two+ years (water levels were variable though, so that just might be it...!))
The two 'true flints' I know are Longfellow (Source CGN Wageningen Genebank, seems to be the real deal) and Cascade Ruby Gold. Our CRG was crossed up when we received it (with a lavender flour corn most likely) but after some cleaning up I am rather sure that they have the same kernel type.

So.. the Longfellow/CRG kernels are just as carol described. Very hard starch, thin pericarp, cooks quickly and is delicious (especially the red CRG in my opinion!).

We also grew some Italian polenta varieties. I fell in love with the "rice type" pointy kernels of the "Rostrato" Group of italian polenta corns. In Italy, several forms exist.

Narrow and long cobbed true flint types (that might be confused with popcorn (the pericarp is too thin for popcorn though.))
Some of these have a very orange flint endosperm. They probably have Corioco (sorry that might be wrong, what's the race of Argentine/South American flints?) ancestors.
The pericarp is thin and in most varieties it is colorless. Red and "Sun/Halo(?)" pericarps can be found too.
There are also semiflint/semident forms of this group. These varieties were probably crossed with North American gourdseed varieties some 150 years ago. They have huge ears and rather large pointy kernels. Sometimes you find cobs with 22-24 rows. It ripens about 5-6 weeks after Cascade Ruby Gold - so the yield is potentially much higher (the water use as well). Also, CRG is much more colorful and beautiful!
Typical cook and bake polentas of course...

(This type may be available in the USA named "Floriani Red Flint", I am not 100% sure though.)

We crossed this type with CRG and selected the progeny for flint type, pointy rice type kernels and lodging resistance.

The flint types we got from this cross have a softer type of flint endosperm.
I have to admit that I don't have an instrument to measure this.. but it is rather obvious after hand milling kilo after kilo of Rostrato Rosso X CRG and Longfellow.
I also poked and cut many kernels.

As far as I can tell the true flint types cook as fast as Longfellow but the consistency and taste (taste is probably pericarp related..) are different. I don't think it tastes raw.

But I have to admit that sometimes I like to eat mushes made out of semiflints or even dents - they are a bit creamy/slimy but for me they never taste raw after only cooking (which takes much longer than with the true flints of course.).

Oh, we also got progeny that has no woody part attached at the kernels at all. You can see right to the black layer at all kernels of those cobs. Does someone know if this is a special trait of the rice type pointy kernels? All the "normal" flints (of the North American  Flint and Flour Gene Pool) have some woody stuff that is attached after threshing... Happy accident if this is stable..