Inbreeding/Diploid Drone risk

**Jon** · 06-07-2010, 09:46 AM

Big Man or Jimbo or any other closet geneticist:
I have a queen which had been laying for a week.
She is a daughter queen of colony 31 in the DrawWing thread.
She was mated in an Apidea at an Apiary with Galtee Drones and is now back home in a 5 frame nuc.
There are 12 colonies in the other apiary and I think almost all of them are headed by daughters from the same Galtee queen.
I grafted some larvae from my new laying queen.
What are the implications for mating any queens hatched, assuming there are not too many drones coming into either apiary from outside?
My apiary would be more diverse than the other one but, any new queen would still meet a lot of related drones. I was encouraging Colony 31 to make as many drones as possible.
Is there an advantage of using one Apiary over the other or are the inbreeding risks the same in each case? Or is the risk nothing to worry about.
I imagine this is back to genetic diversity in the drones and csd locus.

**gavin** · 06-07-2010, 07:18 PM

Did somebody call?!

OK, the csd (complementary sex determination) locus. For those who don't know, if you have two different copies of this gene, you're female (if you are a honeybee). If you have only one version, your egg wasn't fertilised and you're male. If you have two identical copies then you'd develop as a male but the patrolling workers usually eat you before you get far.

First of all, any theoretical assessment is likely to be wrong in practice. Queens and drones will mate with whoever they like (rascals) (unless you force the issue), so nothing is guaranteed. However ....

I'd worry more about in-apiary mating of colony 31 daughters with colony 31 sons. What would they represent - half of the available drone force in your apiary? Those matings would give perhaps 50% diploid drone eggs, and so if half of the semen comes from them then you might expect 25% dd eggs. Not good.

Is Mervyn's apiary much better? Maybe. If he had one queen mated with well-mixed drones, then raised quite a few queens from that queen, he would have captured the diversity at the csd locus represented in her spermatheca. He would still be much better with other Amm blood though - ask him about it!

But the best option is for you to find another source of decent Amm soon, and add that to your breeding stock (or take your virgins there).

Inbreeding probably affects vigour in other ways too, so too heavy a selection (especially when the apiary is isolated) may be good for the things you are selecting, but bad for overall vigour.

The advantage of *this* forum is that there is at least one other card-carrying Amm-sympathetic geneticist here too (get Margie taking part and we'll have three) ... so the second opinion ought to be along soon!

Gavin

**Jon** · 06-07-2010, 07:32 PM

I think Mervyn buys in a new queen each year which is the one he grafts from. The drones in the Apiary are produced by a dozen colonies which are headed by daughters of the previous years Galtee queen. He has just lost this years breeder queen so intends to graft from a couple of my colonies. He faces the same problem in that he has a 2 year old Galtee queen but all the drones in his Apiary are related to it. I should probably graft from his queen and raise the cells in my own apiary for mating.

PS Who's Margie? The more the merrier.

**gavin** · 06-07-2010, 09:01 PM

Mervyn has it all sorted, as you might expect.

It seems that Mervyn's apiary has purer Amm than yours. However if your drones are dominated by your more Amm-like colonies, then grafting his queens and mating them at your apiary has its attractions too. For one thing you may have some real Ulster genetics there, whereas Mervyn has gone over to pure Galtee blood.

Do you know the origin of the Galtee stocks and how broad they are genetically?

One day you might have Amm queens to spare for enthusiasts in Middle England who seems to be unable to source them locally.

Margie shares my surname, thanks to husband Jock to whom, as far as I know, I am not related. She was at SCRI for a while and now lives in an enchanted place in Wester Ross.

G.

**Jimbo** · 06-07-2010, 10:00 PM

Hi Jon,

Gavin has given the answer and explained it better than I could. He being a practicing Geneticist and me being more a desk jockey Biologist.
In -apairy mating is a worry if you are trying to improve the strain. When I started I had 5 good Amm colonies and bred other more unrelated hybridised queens with them to improve the Amm charateristics and to have a better mix of drones. This year I have mixed and matched again. I have 3 sites so can isolated the not so good colonies and take queens for mating to the site that has the best Morph results.
I do have a few concerns. The first is at present I am selecting just on the wing results i.e by using the best wing values I could just be improving this characteristic Gavin might be able to explain better. The second is sourcing good Amm queens to improve my stock. So far I have not seen any inbreeding signs but with so few colonies and some now related I think is only a matter of time. I have arranged to get a queen from Andrew Abraham for next year to improve my stock. I think there is opertunities through the forum to exchange queens, however there are few people trying to improve the Amm and the added complication is some of them do not have varroa therefore we can't freely move queens about.
Gavin might also be able to explain this but Andrew on Colonsay I think has about 35 colonies which are all Amm and have been in isolation for a number of years. Why does he not get in-breeding or is it a matter of time with such small numbers.

Jimbo

**gavin** · 06-07-2010, 10:22 PM

Hi Jim and All

Inbreeding as an issue has been much exaggerated in some quarters. Sure, if you have a really small number of colonies at an isolated site then you may have problems. However 35 colonies is a big number and the diversity stored in that number could be huge if the founding colonies were also diverse. Just one colony (queen and the sperm she carries) could have most of the diversity present in the area - but take one queen to one daughter and repeat, and you will have serious inbreeding issues.

Queen-swapping could be one of the big benefits of a forum like this.

Jim, in your situation - where you would expect some fairly pure Amm to turn up - I'd rely on wing morphometry as a first means of selection. It is straightforward, and relies on several genes. To do the job properly you might like to follow Peter Edwards' stud book criteria where a range of Amm traits are used. He has done marvellous things with Amm in Warwickshire.

G.

**Jon** · 06-07-2010, 10:17 PM

Originally Posted by gavin

For one thing you may have some real Ulster genetics there, whereas Mervyn has gone over to pure Galtee blood.

G.

I have some nice colonies and there is no way I want to ditch what I have to start again with Galtee or anything else. I do like the idea of getting some Galtee into the mix though. Mervyn has lovely bees which he works bare handed.

Originally Posted by gavin

Do you know the origin of the Galtee stocks and how broad they are genetically?
G.

I will be able to corner a few people in a bar in Cahir with questions like that in September.