Tobacco Photoperiod Sensitivity

[JessicaNicot]

Although the majority of tobacco varieties are insensitive to photoperiod, photoperiod sensitivity was actually discovered first in tobacco. These sensitive lines, often designated "Mammoth", will only initiate flowering when the nights grow long (typically referred to as "short-day" plants). I just happened to have the chance to share with you the remarkable difference in phenotype for Maryland Mammoth plants seeded at different times.

The first is from last year's grow out. It was seeded on Feb. 15 and later transplanted into the field in May. The picture was taken on July 30 and the plants did not flower until mid-August. I know there isn't anything for scale but that plant is probably 6ft tall.



For comparison, this is the same seed lot of Maryland Mammoth, except it was seeded on Aug. 13. It was subsequently transplanted and grown in the greenhouse under natural light conditions. This picture was taken on Jan. 21 and the plant is roughly waist high (including the pot).

 

[TheOtherOne]

What an amazing strain! I wonder if one could acquire this trait in other strains by cross breeding, and double or triple back crossing with the parent, selecting only the plants with the parent phenotype that show photo periodic behavior.

Do you know if it's dominant, or recessive Jessica?

 

[JessicaNicot]

I don't know off hand if its dominant or recessive. I can try to look it up. we are actually initiating a study on this in our lab.

 

[holyRYO]

photoperiod sensitivity was actually discovered first in tobacco

Tobacco (and beer), "the mother of invention". Interesting plant, thanks for sharing, great pics. Wonder why it is not a commercial success? Making seed too hard? Desease prone? Smoke quality?

 

[JessicaNicot]

not conducive to commercial production. you can see from the first photo that there are like 10 leaves lost at the base before the plants even flower. it would require many, many harvests and the leaves aren't all that big in comparison to standard commercial varieties. I don't know what the flavor would be like. put it on the group request for next year and find out =P

 

[Knucklehead]

Jessica, we need to get you a pipe for sample and tasting. It would be good of you to add smoking and flavor characteristics to the Observations pages of all your accessions.

 

[Jitterbugdude]

I second that motion!

 

[JessicaNicot]

well for that I would rely on all of your expertise here on the forum because I don't smoke. once the new GRIN is up and running and I can figure out what im doing, i'll solicit you guys for input on smoke characteristics.

 

[holyRYO]

i'll solicit you guys for input on smoke characteristics.

Ready and willing volunteer.

Jessica, is this how they breed non flowering hybrids like NC 27 NF and NC 37 NF?

 

[JessicaNicot]

I want to say yes the NF varieties came from a cross to a mammoth type, but i'm having trouble locating a reference that can tell me the pedigree of the first variety, NC 22 NF. It was developed here at NCSU by my boss' former adviser (Dr Earl Wernsman), but my boss is on vacation for a couple more days and Dr Wernsman retired several years ago. I will ask him when he gets back later this week.

 

[Knucklehead]

If it's not the daylight hours that trigger flowering, what is the recommended on/off times of grow lights for starting seedlings?

 

[JessicaNicot]

our growth rooms are on continuous light. how that impacts germination compared to a natural light cycle I can't say. but I do know that our seed germinates just fine and our little plantlets seems to be quite happy with it. they switch to a natural photoperiod when we move them to the greenhouse.

however, if you grew a mammoth variety under continuous light it would never flower and I suppose continue growing indefinitely. non-photoperiod sensitive tobacco (most tobacco), put simply, grows to a roughly predetermined number of leaves and then flowering is induced regardless of the light cycle it receives (but this can be overridden by environmental stress signals such as cool temperatures, root binding, etc).

 

[JessicaNicot]

ok. so we just followed the pedigree info for the NC NF lines and they do trace back to crosses made to an unspecified mammoth variety. the article regarding the transfer of photoperiod sensitivity is: Wernsman and Matzinger (1980) Mammoth Genotypes and Tobacco Management Regimes for Reduced Production of Downstalk Tobaccos. Agronomy Journal Vol 72 (No 6):1047-1050.

the photoperiod line that was the source for the NC NF cultivars was SC 58 Mammoth.

also, the article states that photoperiod sensitivity is a recessive trait conferred by two loci.

 

[Mad Oshea]

Now is the White Mammoth in the same catagory? I am using all natural light this year to start. However I do see a stall in all of the plants without the grow lites. I may change to both.

 

[holyRYO]

Now is the White Mammoth in the same catagory?

Based on a maturity of 56 days, I would guess that is not a true mammoth.

 

[Mad Oshea]

What would it fall under due to how to cure it? This is the first time in My grow and wasn't sure. Thanks

 

[Mad Oshea]

Knucklehead posted White Mammoth is in the same cat. PI 552336 and is a flue cure.

 

[JessicaNicot]

I've not grown White Mammoth yet but the pic that's up on GRIN from a previous grow in 2005 doesn't seem to be a true mammoth (photoperiod sensitive) variety at all. It just so happens that it will be out in the field this year, along with two Yellow Mammoth varieties (regular and black shank resistant), two Black Mammoth varieties (regular and mosaic resistant), Mammoth Yellow, Mammoth Gold, and Maryland Standup Mammoth. I'll report back in late summer on which are actually photoperiod sensitive.

 

[Mad Oshea]

That will be very interesting. I like the Mammoth types and am looking forward to see how this one looks compared to the plants You have in the feild. Hum? Would be nice to see if it acts like the other mammoth types as well.

 

[holyRYO]

I could not find anything on White Mammoth. Mammoth Gold is Gold Dollar X Mammoth Yellow, another suspect true mammoth (photoperiod sensitive) based on time of maturity. The three true mammoth types I found so far on GRIN are: Maryland Mammoth, Maryland Standup Mammoth, and Burley Mammoth KY16. Solom IV looks like it wants to be a mammoth, longish maturity and lots of leaves.

Jessica, the NC NF is fascinating work. I want to thank you for all that you do for this forum, go Wolfpack!