Genetics , Breeding and Cross Breeding

[jwhtan]

We've always been talking about crossbreeding of the different strains and many of us just put two and two together and arrive at some individual conclusions.

I thought it may help if I put together my understanding on breeding and perhaps others who have in depth studies can chip in and please, do correct me if I'm wrong.

What happens when u crossbreed ?

In the first parental cross, the F1 will always see only one of the two parental phenotypes in this generation. That is assuming u r able to pair different breeds together in arowanas, if u breed a Red with a XBack, you get in this first generation an aro that looks either like the Red or the XBack and not a combination of both. Or that if you breed a RTG with a XBack, you will get an aro tat looks like an RTG or a XBack and not one that is a combination.

However this F1 generation holds the all most important genetic composition of both parents tat is required to produce both parental phenotypes of the following generation. This F2 generation always produced a 3:1 ratio where the dominant trait is present 3 times as often as the recessive trait.

In order to henceforth produce a particular strain which breeds true, this pure line programme would then have to be picked from the F2 generation tat produces the dominant traits for future breeding.

Looking at this complicated process of a genetic programme and knowing the difficulties and the time required in a programme like this, do u still think the farmers will put rtgs and xbacks for a breeding programme to produce the so called hiback rtgs ???

[Aroboy II]

To the local breeding farm, as long as their breeding program make profits I think they will! IMHO.

[LostBoI]

actally i fully agree with ur point...
won't it be more profitable to breed xback instead of a HBRTG?
since the time taken and resources involved are the same.

why would they wanna do the xback and RTG instead...

hmmm

Originally Posted by Aroboy II

To the local breeding farm, as long as their breeding program make profits I think they will! IMHO.

But issit profitable to commission XBs into this process while they could actually have those XBs producing more XBs which are much more profitable?

Also, not to forget the difference in pricing of these "HBRTGs" and normal RTGs nowadays do not differ much

[jwhtan]

wat I'm saying is tat if u put a xback and a rtg to breed, u dun necessarily get a hbrtg

in this first generation if they breed, wat happens is tat in genetic theory this generation (we call F1) can look either like a xback or a rtg ...

4th level + 6th level does not necessarily add up to 5th level for the offsprings

[shiokmc]

YALOR..... ultimately offspring will end up as RTG or XB whichever parent's Gene is stronger lor

[Aroboy II]

Originally Posted by Mewmender

But issit profitable to commission XBs into this process while they could actually have those XBs producing more XBs which are much more profitable?

Also, not to forget the difference in pricing of these "HBRTGs" and normal RTGs nowadays do not differ much

If like that wont the farm choose the "lousy" XB and breed with RTG lor!

How about if its done with F2/F3 offsprings Xbreed XB/RTG instead of F1 offsprings?
Does your point of view includes farms in overseas like Indo??

Originally Posted by Aroboy II

If like that wont the farm choose the "lousy" XB and breed with RTG lor!

nah, its much more commericially viable for them to sell them off at cheaper price imo . No pt keeping them till maturity juz for such a "experiment" .
Its also not commericially viable to use up ponds and tanks which could be use for futher production of their current breeds for up to 2-3 years to keep those "lousy" xb for breeding.

Also not to mention a farm has to produce more thn 1 batch of such hybrids (from different parents) due to the fact that when the inbreeding has reach 60 to 70 %, the fertilitybecomes very low because of the inbreeding depression, that further inbreeding has been impossible..... which basically means at least a few different lines of such hybrids have to be produce to mantain production of such fishes ....

[jwhtan]

Originally Posted by kimkuan

How about if its done with F2/F3 offsprings Xbreed XB/RTG instead of F1 offsprings?
Does your point of view includes farms in overseas like Indo??

does it make economical sense to u for the farms to do this ?

take a count , from the first parents of a Xback and a RTG (assuming they does this) to the F3 generation to produce this .... say 15 years .... 15 years to use XBacks to breed and with a carefully selective programme with these extensive efforts to produce this strain which is not exactly well priced, would u do this ?

or u would have used the xback breeding stocks by itself to produce more xbacks ?

this is assuming that farms in Indonesia have an abundance of xback breeding stocks which in reality, they dun have