Expressed Genetics:

[SmokesAhoy]

Am I wrong or are genetics always expressed in each plant? i was having a pipe dream, about growing out a single plant for everything in my collection. from experience i know some plants just grow retarded. if i grow 1 plant each and bag the special one those seeds would still be good for the genetics right? the issue with plant being less than spectacular could be from any number of reasons but the genetics should be expressed in the progeny just fine?

i'm starting to worry my seeds wont last forever just growing a few varieties, and some havent even been sampled.. my entire collection could be regrown in 3 rows though. i just want to make sure if i bag an underperformer that wouldnt only express under performing genes?

 

[wrigsted]

Unfortunately, my english is not up to answer your question, but I think I can point you in the right direction. Try to look at http://en.wikipedia.org/wiki/Genotype-phenotype_distinction it might give you some answers.

 

[Jitterbugdude]

If you bag an under performer it sounds like you are selectively breeding for that trait. Do it several times and you'll have tobacco seed that "naturally" under performs.

 

[notcrack]

It would also depend how many genes the tobacco plant has. I did a quick search, but couldn't find a number. From my understanding the higher the number of genes the more difficult it is to isolate mutation.

 

[deluxestogie]

JBD is correct on selective breeding. Tobacco, like all plants and animals, also uses non-gene materials (epi-genetic) to regulate not only the expression of the genes that are present [a particular genetic trait may be present in the genome, but not allowed to develop], but also the subset of genes that end up in its eggs and pollen. This epi-genetic impact on future generations is subtle, but does occur. Epi-genetic effects are often regulated by growing conditions or herbivore predator impact.

Although heirloom varieties have a fairly predictable set of genes from one generation to the next, a good way to think of its genome is like an omelet, always made with the same quantities of the same ingredients. When you cut it in half (I eat one half, you eat the other), which is analogous to the process of creating eggs (no relationship!) and pollen, you may get more cheese, while I may end up with extra mushrooms.

Even with careful bagging and knowledgeable plant selection for seed, and from a large number of specimens, every variety of tobacco grown by an individual grower will gradually "drift" from the original specimen.

I've grown PA Red using seed from two different sources: 1) New Hope Seed and 2) Nicotiana Project. The plants from batch 1 were all consistently taller, with wider leaves, while the plants from batch 2 were all consistently shorter, with longer and somewhat darker leaves. They are both easily recognizable as PA Red, and taste pretty much the same. But the two genetic lines have drifted apart in subtle ways.

Seed from a single seed pod is not genetically the same, even when "selfed." Given the huge number of seeds in that single pod, the entire lot of them likely has representatives of every possible combination of traits available within that individual plant's genome. When you germinate, say, 50 seedlings from the lot, every plant will be genetically unique, though most of them will strongly resemble one another, as well as the parent. From these, you can easily select a "typical representative" of the variety to bag. If you raise only a single plant from the lot, you may or may not grow-out a typical individual. Chances are (statistically) that it will be typical. But it may not be.

Sorry for the long-winded response. Some members may find it useful. Many may not.

Bob

 

[Jitterbugdude]

Sorry for the long-winded response. Some members may find it useful. Many may not.

Bob

Don't worry Bob, Daniel is no longer with us...

Good explanation!

 

[leverhead]

I can tell when I have too much information, I remember a teaser and then spend hours finding the source. Google needs to put out a "civilian" search engine to go into the files. Thank you though, I love detail.

 

[Michibacy]

JBD is correct on selective breeding. Tobacco, like all plants and animals, also uses non-gene materials (epi-genetic) to regulate not only the expression of the genes that are present [a particular genetic trait may be present in the genome, but not allowed to develop], but also the subset of genes that end up in its eggs and pollen. This epi-genetic impact on future generations is subtle, but does occur. Epi-genetic effects are often regulated by growing conditions or herbivore predator impact.

Although heirloom varieties have a fairly predictable set of genes from one generation to the next, a good way to think of its genome is like an omelet, always made with the same quantities of the same ingredients. When you cut it in half (I eat one half, you eat the other), which is analogous to the process of creating eggs (no relationship!) and pollen, you may get more cheese, while I may end up with extra mushrooms.

Even with careful bagging and knowledgeable plant selection for seed, and from a large number of specimens, every variety of tobacco grown by an individual grower will gradually "drift" from the original specimen.

I've grown PA Red using seed from two different sources: 1) New Hope Seed and 2) Nicotiana Project. The plants from batch 1 were all consistently taller, with wider leaves, while the plants from batch 2 were all consistently shorter, with longer and somewhat darker leaves. They are both easily recognizable as PA Red, and taste pretty much the same. But the two genetic lines have drifted apart in subtle ways.

Seed from a single seed pod is not genetically the same, even when "selfed." Given the huge number of seeds in that single pod, the entire lot of them likely has representatives of every possible combination of traits available within that individual plant's genome. When you germinate, say, 50 seedlings from the lot, every plant will be genetically unique, though most of them will strongly resemble one another, as well as the parent. From these, you can easily select a "typical representative" of the variety to bag. If you raise only a single plant from the lot, you may or may not grow-out a typical individual. Chances are (statistically) that it will be typical. But it may not be.

Sorry for the long-winded response. Some members may find it useful. Many may not.

Bob

I am a firm believer in the thought that the more that we learn about this creation our God created, the more we learn to love and respect him, as well as others around us. Good information Bob.

Question: What happens when you cross the genes of the two different plants (but same species)?
Is there a way to retreat back to the original genes?



BTW Amen Jitter

 

[SmokesAhoy]

Thanks for the replies, and thank you for your time and knowledge, I don't take it as long winded at all.

So basically I can try growing them all, can select the best seedlings and grow for seed. You can tell when one clearly isn't living up to its potential. I will grow for seeds and if one isn't up to par I can grow it again the next year for seed and top it for sampling. A genetic drift will occur but at least my seedbank will not expire totally over enough years. I figured I would start thinking about this earlier since I don't know how old my seed stock is already.

 

[deluxestogie]

I am a firm believer in the thought that the more that we learn about this creation our God created, the more we learn to love and respect him, as well as others around us. Good information Bob.

Theology was not my intent.

Bob

 

[skychaser]

Great post Professor Stogie. Keep them coming.

The widely accepted standard for maintaining the genetic diversity of a plant species for seed producers of all kinds is the 20/100 rule. Meaning you want to take seed from at least 20 specimens from inbreeding plants and seed from at least 100 specimens from out breeding plants.

Here is a couple snips from "Seed to Seed" by Suzanne Ashworth. Some of you may even have this book. It is considered to be the garden seed savers Bible by some folks. It has specifics on how to grow and harvest seeds from 160 vegetables and is also a wealth of information in general for seed savers.

Population Size:

"Population size is an extremely important factor to be considered during seed production and should always be kept in mind during selection procedures. Maintaining genetic diversity within a population is the key to its continued evolution and the ability of the plants to adapt to varying environmental conditions. To avoid detrimentally decreasing the genetic diversity being maintained within a population of plants, seeds should be saved from the greatest number possible number of plants that meet the selection criteria. For example, never save seeds from only the largest or best looking fruit, which could create an irreversible bottleneck during that generation. Instead, always save seed from as many plants as possible.

Larger plant populations are necessary whenever you are a seed source for others. At the very least, suppliers to seed companies and seed repositories will need to fallow the basic rules of 100 out breeding plants and 20 inbreeding plants. In general, naturally diverse populations and truly unique varieties will always require larger grow outs than, for example, modern commercial varieties that are unusually quite uniform and stable. Keep in mind that even larger populations sizes will be needed if the variety is extremely variable.

Notable exceptions to these general recommendations concerning population sizes involve self pollinating plants, cucurbits and corn. Self pollinating plants all have perfect flowers that contain both male and female parts within the same flower. Most self pollinating plants, EXCEPT those that are also insect cross pollinated such as peppers (and tobacco), are naturally inbred and contain relatively little diversity within any given population. Excellent examples would be many varieties of garden beans, which self pollinate before their flower has opened, and have been saved from only a few pods or a few plants for countless generations. Such highly uniform. self pollinated varieties can often be successfully maintained with populations of very few plants" ...

Tobacco is in inbreeding plant but it also cross pollinates by insects, so the 20 plant minimum rule should be applied when saving seeds. In my grows, I always grow plants in groups of 24, 36 or 72. Usually I grow 36 of each variety. I do not select for, or against any particular traits, other than to cull out any defective looking plants or plants that appear to be far from the norm for that variety. I never send anyone seeds from just one plant. My seeds are always a homogenous mix from the entire grow.

Sky

 

[leverhead]

Thank you, I'm going to look for "Seed to Seed" by Suzanne Ashworth. It sounds interesting.

 

[Jitterbugdude]

. I never send anyone seeds from just one plant. My seeds are always a homogenous mix from the entire grow.

Sky

Sky, What material do you use to bag your plants?.. and do you use the same bags over and over?

Randy B

 

[skychaser]

We are using Agribon now. We were using a similar type material that is used as a filter fabric and is sold at Home Depot. It was cheep and convenient to get. But it lasted 2 years in the sun and then turned to tissue paper. The Agribon is a much better material and when I actually figured the cost per square foot, it costs less than the fabric I got at Home Depot. Hopefully Agribon will last 3-4 years or more. We are currently using the insect barrier grade but will go the the light frost protection grade the next time we order a roll. It still has 70% light transmission. Even the insect barrier grade gives decent protection to early frosts. That made a big difference to us this year.

Yes, we reuse the bags. Had 1290 of them out there this year. My poor wife goes nuts making them as it is. Luckily she worked as a seamstress professionally at one time in her life and is a wizard with her sewing machine. She can make anything. Takes us under 2 minutes to cut a sew a bag now once we got a good system down. But with that many, reusing them is a necessity. First we clean any debris out of the bags and give them a good shaking. Then we put them into big plastic totes and give them a good washing with dish soap and then several rinses of clean water. We fill the totes back up with water and add about 1/2 a cup of chlorine bleach and let them soak a while. Then we dry them out and stow them away for next season. I thought about tossing them into the microwave too but I got "the look" when I made that suggestion to my wife. lol