Genetic Diversity: What Would Brother Adam Do... Today?

[cerezha]

There is a good reason hybrid breeding programs maintain separate lines, and us the cross for "production". Often the inbred lines of bees are very weak from inbreeding.....and subsequent generations are poor...hence maintaininformation the separate lines.Deknow

Yes, I do understand that at the level of many animals but bees. In case of, for instance dogs, we could maintain two pure lines and than cross them. The cross is usually stronger than parenting lines. But in such case we have mother from one pure line and father from another. In case of bees, it is always queen, nobody is talking about drones. Do breeders keep drones pure as well? It seems to me, since drones are haploid, it is easier to keep them pure and transfer "good" genes (hopefully traits) to other bees. In such scenario, we "just" need to bring "pure-blood" colony (pure mother and father) to the apiary to incorporate "good" genes into bees population... instead pollination, insemination by pure drones!

[ScubaMark]

One thing that seems to be being overlooked is that "genetic diversity" is NOT gained by homogenizing from EXISTING genetic materials. Gene variation is not a static value. It, in fact, often arises from geographic isolation. An isolated population may in fact go through a bottleneck due to natural selection. The gene variation which permitted that selective survival then gives rise to other random variations introduced either by "nature or nature's God" (let's not argue which) that subsequently produces increases or decreases in other survival or performance traits.

Certainly, in any given "isolated biosphere" a concentrated inbreeding produces a preponderance of negative gene expressions that are typically not dominant. Hence the need for using "hybrid vigor" to suppress non-dominate negative gene expressions. However, in the typical bee yard exposed to open mating that level of inbreeding is not common. Instead of seeking to "introduce" genetic diversity from other geographical isolated populations, it seems to me that we should spend more time limiting the homogenization of the total species genetic material by ceasing to do so much large scale "inter-breeding" and instead look more toward more localization of queen production.

[JRG13]

I like that approach scuba. I think having a well mated queen from a diverse range of drones makes for a stronger hive.

[Daniel Y]

...you are talking about VSH as it it were brown eyes.....this is a gross misunderstanding of the entire concept of VSH, HYG, and hygienic behavior in general.
These behaviors exist in all populations...the 'trait' is really just an evaluation of where on the continuum a particular hive scores. It is also well understood (and has been demonstrated in both the lab and with independent breeders) that a line that scores highest in hygienec tests pull most of the brood, not just those hosting varroa.
Read Marla's documentation wrt Minnesota hygienic program.....without constant selection for the hyg trait, it dilutes in the population (meaning that if you are not testing and selecting for it disappears).
Most importantly, naturally surviving populations of bees (even AHB ) don't score especially high on these kinds of tests...so they are using other (proven successful) methods to survive the mites.

Deknow

I saw something the other day that says they suspect hygienic behavior may be associated with as many as 7 genes. So you may see excess removal from a bee that expresses behavior due to one gene. and not in the next being that is expressing due to one of the other possible genes. They do seem to have a lot figured out. but I do not think they know it well yet.

In addition the traits all so far seem to be recessive. this is what makes loosing the traits such a problem.

Any trait that is not continually selected for will be lost.

As for gathering a wide diversity. There is no longer a need to travel to do so. have them sent to you. The need to have an eyes on evaluation becomes considerably less when the queens cost you comparatively nothing.

If you toss out hundreds of bees that cost you a few dollars each. it is the same as spending hundreds of dollars on travel to hands on evaluate them. Plus hands on evaluation is not as critical now with the ability to share data. You just need the numbers to make a selection basically. you don't need to see a bee.

You can get queens from beekeers from all over. if you best hive makes a queen cell mail it to me.

You can get queens from queen producers. not terribly expensive but open mated. the genetics are not all known.

You can get queens that are from queen breeders with fairly well known traits and also an already narrowed gene pool.

Efficiency comes at a price. Cheap means you get a lot of unwanted genes. expensive means keeping the gene pool still comparable narrow. Less to clean up. more chance of lost beneficial genes.

[deknow]

Sergey, breeders do consider the drones.
Most use "drone colonies" and either flood the area with drones of their choosing, or go to a place that doesn't have other bees (an island, a mountain).
If one is going to introduce genetics, the best way is via drones. Breeder queens are purchased in the summer and grafted so that many of her offspring will overwinter. Since the drones produced by these offspring are not influenced by their mating, their genes are completely of the population the expensive breeder queen came from. This maintains the genetics you have already established while adding the genetics you want to add.
There is some disagreement as to how far from the mating nucs the drone colonies should be....but many just keep them in the same yard.
Bees have a lot _f mechanisms in place to prevent any kind of "pure mating"...not the least of which is the sex determination gene. This is. System that is designed to run "dirty".

Deknow

[Daniel Y]

The drone is half of the queen genetically. so if you took a number of drones from the same hive you are pretty much guaranteed to get all the genes from that queen.I am not sure what the number is. I have seen people gather as little as 10 drones from a hive.as many as 100 or more. I woudl tend toward the higher numbers.

The sperm of a drone are clones of it's genetics so that is the point you reach the lowest genetic diversity in a honey bee. This is countered by queens that mate with multiple drones from multiple hives. it is also the point you can consolidate gens intentionally. much attention needs to be paid to drones. Problem is drones don't express a lot of the traits they carry. they don't work. You have to look to the queen and the workers for an idea of what they even carry.

[jim lyon]

There is some disagreement as to how far from the mating nucs the drone colonies should be....but many just keep them in the same yard.
Bees have a lot _f mechanisms in place to prevent any kind of "pure mating"...not the least of which is the sex determination gene. This is. System that is designed to run "dirty".

Deknow

There is a theory out there that queens don't breed from their own drones because thevirgin can fly faster than the drone and therefore will get mated by drones further from her hives. I had an experience a few years ago that shot down that theory in my own mind. We had a large group of nucs that were woefully short of drones so we placed the nuc yard less than a mile from one of our strongest yards where there was no shortage of drones thinking that it would help greatly with mating. Both yards have had histories of high percentage matings. The end result was a miserable queen catch in the poorer yard and an excellant catch in the better yard. The better yard was probably about a week ahead so the matings were happening on different days.

[deknow]

Ok, first, let's look at hygienic behavior...commonly referred to as hyg. All bees are hygienic to some extent or another. .let's make an analogy to a person running fast. There are lots of factors that can go into running fast...the length of your legs, your muscle strength, training, desire, etc. You can make some assumptions of how fast someone can run, but if it were easy to do so, we would know the winner of every race ahead of time. Being "slow" in such an evaluation does not mean that one is unable to move..."fast" and "slow" are two ends of a continuum, not discrete traits like brown eyes, and can be influenced by a number of genetic factors.

This is what hyg is....it is the ability of the bees to sense and remove a lot of dead brood from underneath the cappings...and to do it quickly. It is not really possible to judge hyg through casual observation (I know Mike P. has said he selects for hygienic behavior by selecting for colonies with not chalk.....this assumes that hygienic behavior is the sole genetic defense against chalk that the bees have...I don't believe this to be true. Mike appears to have selected bees resistant to chalk, or cleaned it out of his equipment over time...his bees may display a high hyg score, but I would not bet on it).`

To evaluate hyg, one must kill a known number of capped brood (usually either a pin prick or liquid nitrogen poured within a ring), and see how fast and how completely the bees remove the dead brood. This is the test for hyg...not if you see brood being uncapped because of varroa, not if you see a clean bottom board.

Hyg was seen as a way to breed bees to be resistant to AFB. The idea was that if the infected brood could be removed quickly and completely, the reproduction cycle of the bacteria could be interrupted. This was found to be true.....but it was a "brink" effect....the bees could resist AHB if they could remove 94% of the dead brood in 24 or 48 hours (I forget which was used), but below this 94%, they were not resistant...they were not almost resistant...they were not kind of resistant. Other methods of breeding bees that are demonstratively resistant to AFB have been done successfully, but I don't think they were ever tested for hyg.

....more later when I have time....

deknow


It was first looked at as a way to combat AFB

[jim lyon]

I know Charles Mraz was working on that quite extensively years back. We bought a bunch of queens from him, and it did seem like they showed quite a bit of improvement in disease resistance. My main recollection, though, was that thosebees were M E A N. I have often wondered if the hygienic traits that are beneficial in AFB removal isn't a big reason why we see so much less AFB than we did years ago.

[deknow]

The hyg and vsh traits (which are behaviors determined by a number of genes) are recessive. In fact, they are not so much "traits" as "hyperexpressions of behaviors" that are obtained through careful selection pressures.

It is worth noting that selecting for survivors is not sufficient selection pressure to select for hyg or vsh. If you want stock that will score high on these tests, you have to perform the tests and select based upon the results.

We often see beekeepers or clubs who want to start a local breeding program buy VSH breeders in an attempt to breed these with whatever is available locally to produce a varroa resistant/tollerant local stock. ...but, these beekeepers and clubs rarely test for hyg, and even more rarely test for VSH (there is not a standard assay for this, and those that are used are cumbersome at best).

If you think the VSH trait is what will give you mite resistance, then you have to actively maintain that trait by testing and selecting for it, not just select for survivors. If you don't, you will lose the very trait that you are counting on for your mite resistance in just a few generations....so much for the local resistant stock you are trying to build.

[deknow]

Natural selection and artificial selection share the same mechanisms....inbreeding to fix traits, outbreeding to introduce new traits. If have a population of bees that is "fit"....an entire population that you are happy with, then by all means, breed from all the bees...make walk away splits and increase your numbers.

But, what if your population is unfit? What if you are not happy with the performance and you want to "improve" your stock?

You may want to bring some stock in if you think what you have available is total junk...but once you do that, you have to let things settle out. To some extent you want to fix the population with the traits you care about, and discard those that you don't. In my case, I'm not smart enough to know exactly what traits and in what proportions the bees need, so I look at "meta traits"...survival, temperament, production mostly.

What happens when you lose most of your bees to a bad winter? Assuming the survival is, on balance, a genetic factor, you inbreed to some extent with what is left....fixing some of those tratis in the population...something you could never do if you had drones and queens from the colonies that "died of starvation because you didn't feed them over winter". In our case, we see frugal overwintering behavior in our stock....not anything we evaluate separately from survivability.
....more later...

[jim lyon]

Dean: I have heard this before and I have trouble accepting the fact that if hygienic resistance is, in fact, a beneficial trait then why wouldn't it also predominate in strong surviving hives? Aren't the same hives that survive the very ones that have shown some sort of propensity to fight off mites either through hygienic traits, or possibly through physically combating mites or even other means such as shortened brood laying seasons. The end result is the same,bees that have learned to tolerate mites to a higher degree.

[deknow]

Jim, it has to do with the "expense" of the behavior. If you were going to open a restaurant and were hiring kitchen staff....you want to make sure that food does not get contaminated. Staff that washes their hands after they use the bathroom, or when needed is what you want. Staff with OCD who was their hands every 2.5 minutes would also give you the same result...no contamination of food...but would be far less productive.
I don't know what the "traits" are that allow unmanged bees to survive....but I know those are the ones I want to work with.

deknow

[Stonefly7]

Dean, What are your plans to re-start? have you decided on any queen sources as of yet? You are going to breed, correct! Not sure what unmanaged bees are.

Jim, are you breeding at all, or purchasing stock from your breeder? I have seen controlled breeding work in a operation of 600 to 800, by having replacement queens and nucs ready for production colonies, replacing losses, etc, but have not heard of or seen that in larger operations.

I am not sure about the hyg hype either. I have never tested or looked. Just don't have the time. Isnt MP doing just that, or is he testing?

[jim lyon]

Jim, are you breeding at all, or purchasing stock from your breeder? I have seen controlled breeding work in a operation of 600 to 800, by having replacement queens and nucs ready for production colonies, replacing losses, etc, but have not heard of or seen that in larger operations.

We have brought in a few breeders (including some Hygenic) in the past and will do so in the future but mostly just select from our best hives. I sure don't consider myself a true bee breeder but we are operating around 5,000 hives so we do have a lot of diversity to choose from.

[Adam Foster Collins]

...
It is worth noting that selecting for survivors is not sufficient selection pressure to select for hyg or vsh. If you want stock that will score high on these tests, you have to perform the tests and select based upon the results....
If you think the VSH trait is what will give you mite resistance, then you have to actively maintain that trait by testing and selecting for it, not just select for survivors. If you don't, you will lose the very trait that you are counting on for your mite resistance in just a few generations....so much for the local resistant stock you are trying to build.

This only makes sense if you're bent on maintaining VSH. If you're bringing in VSH bees as part of an attempt to establish bees that survive, and that trait helps them survive, then why would you need to test for it? If the VSH trait is what keeps them alive, why would you have to select for it in some other way? How are you going to lose the trait?

Like you, I see myself focusing on "meta traits" as well, so I care far less about the traits that keep them alive than the fact that they are living. So I am wondering if it is wise to get a fairly wide variety of bees from a number of different breeders to provide the widest set of variables to begin with. And from there, select from surviving colonies. I know it's 'heavy handed' but I'm trying to sift out the best way to move forward, while allowing for the fact that there is so much unknown about the how bees survive mites.

Adam

[deknow]

Because only high levels of hygienic behavior are effective, and the behaviors are the expressions of a number of separate (mostly recessive) genes. Such high levels are extremely unlikely to occur by chance, and I've not heard of anyone who has found or maintained these traits without specific selection for them.

[squarepeg]

fantastic discussion here, many thanks to all.

[grozzie2]

I don't know what the "traits" are that allow unmanged bees to survive....but I know those are the ones I want to work with.

Over the last couple years, we got an interesting lesson regarding 'unmanaged bees'.

Short back story. 2 summers back, when we started with bees, it came up in conversation with a friend, they have a hive in the eaves of the house, its been there 'forever'. We were interested, could be an interesting source of survivor ferals. So, we went and looked, sure enough, bees coming and going in june. We set out a trap, but, didn't get anything in it. Our friends are of the 'live and let live' mindset, so they dont want the bees removed. A couple weeks later, talking to the retired couple across the street from us, apparently they owned the house prior to the current folks, lived in it for 20 years, and had bees in the eaves the whole time, and it was normal for a local keeper to be called in the spring, to retrieve swarms.

Soo, as fall came on, we watched the hive, and it had plenty of activity. Winter rolled around, activity died off as expected. In the early spring, we started checking regularily, on days when our hive beside the house was flying, to see about activity in the eaves of the old house. None. No bees at the entrance, no dead bees on the ground, not a sign of any bees. By mid spring, our hives were flying every day, and when we checked the old house, again, no activity at all. About the time we were starting to watch our hives for swarm preps, we got a call from the folks, the bees have 'woke up for the summer', apparently there was suddenly a lot of activity at the entrance.

The lesson learned from this. Homeowners and prior owners were happy to give us a 30 year history of bees in that eave, they honestly believed the bees were there the whole time. But, watching, and knowing a bit of what we are watching for, we realized, that eave did NOT support a colony thru the winter at all, but, one of the first swarms of the spring happily moved in.

The lesson from this, even when the property owners are absolutely positive that the wild bees have been in that spot forever, doesn't actually make it so, and, they may not be feral survivors at all. For the better part of a year, we believed that colony was a long time survivor, and, we had contemplated numerous ways to try capture some of that line into our own bees. But it was all for naught, watching them carefully over a winter / spring, showed us, it's not a long surviving colony at all, it's a 'happy home' for an early swarm.

[cerezha]

Sergey, breeders do consider the drones....Deknow

OK, thanks, it make sense. Is it possible to make a colony with a lot of "good" drones and set it in the apiary to enhance the population with "good" genes originated from the drones-colony? It looks like the easiest way to introduce "good" genes, right? Of coarse, in such scenario, bees should rise their own queens (inseminated by "good" drones). Thanks for responding on my message!