Back Cross to P1

[OnceUpon]

thank you ACE!
i am inspired by your breeding techniques. and thankful for your willingness to discuss them
i have noticed a "theme" in a few of your lines:
Tikal, KaliChina, Nepal Jam

in all of these three you started with F1 (Nepal x Jam for example) then after selection back crossed to P1 parent (Nepal)

starting with a "stable" or inbred line, in your case a landrace, this technique looks like a fun way to introduce vigor, variation and new positive traits into a line. without adding too much variation or making results too unpredictable.... im just guessing, is this the reasoning in this case?

love reading about your breeding
thanks again!

 

[dubi]

Hi OnceUpon,

That's indeed a very good question

Some of our strains (Tikal, Kali China and Nepal Jam) were originally outcrosses that were backcrossed to one of the parental lines, then the result was worked for a few generations more until (as you correctly pointed out) achieve proper stability but also more positive traits from the outcross, and even new traits found on the way in newer generations that were not initially found in the outcross or in the original parental lines. Each case is different, each generation can be different too .... indeed these strains were not bred strictly by backcrossing, as we didn't use the same parental plant in the outcross and in the backcross, the backcross was done using different parental plants from same line/population, it's more a backcross to the line than a backcross to one unique parental plant, but i leave the terminology for the genetists.

A few general tips that work well with this kind of breeding technique:

- Start with a good and stable line of your taste. Choose the traits you like from the line and that you want to fix and emphasize through the breeding. Keep these traits always in mind.

- Cross your stable line with as many different stable lines as possible to produce outcrosses: F1s and poly hybrids. Then evaluate their outcome and the dominant and recessive traits of your stable line in the hybrids.

- Choose the hybrids that have produced best results, showing the traits you like from your stable line even in a stronger way thanks to hybrid vigor, adding new desirable traits from the other side of the hybrid, or with a bit of luck maybe you can even find unexpected new desirable traits that were not found in the lines used to create the hybrids. Although this last case happens more frequently in complex polyhybrids or in F2 generations rather than in backcrosses.

- Backcross the best specimens of the hybrids back to your stable line. To do this you can backcross to the same concrete parental plant from your stable line that you used to produce the first outcross, or to another plant of the same family (could be a sister, brother, cousin, father, etc ...) but always from the same stable population and with the same (or as similar as possible) desirable traits from the stable line you want to improve.

- If correctly done (with good breeding criterias, with big populations, and why not with a bit of good luck) the backcrosses will easily produce offspring that in a high % have all or most of the desirable traits from your stable line, but shown in a stronger and more vigorous way, adding also new traits coming from the other side of the hybrid.

- Keep in mind that a more or less small % of the offspring of this first backcross will show strong traits from the other side of the hybrid, for example if you are working on an indica x (indica/sativa) backcross (considering that only one stable indica is used in the formula) and if your breeding goal is to stabilize and improve the indica stable line, you still will find a small % of the plants in the first backcross that will be very sativa, don't worry about that, discard these kind of plants that are bringing you to the wrong way.

- Choose best parental plants from the first backcross that show all the desirable traits of your main stable line but with more vigor, potency, resistance, ... and with extra desirable traits that were not found originally in the stable line. Inbred these parental plants to truely start to stabilize the hybrid.

- Use multiple lines through the inbreeding process to avoid endogamic problems in mid/long term.

Success is not guaranteed and it will take lot of time and resources, but you will learn A LOT

 

[akirabull]

wow i love thats threads , thanks dubi.i discover the breeding game as a harder job, i like it very much , i made few experiments in last three years and obviously what start as simple test is now challenging me. it's not so easy ,find ,maintain selected genetics of both sex ,doing crossings, testing strength , offspring and make your own stash. dubi when did you start thinking to be a breeder? did you start alone? what i did last years to start my game was choosing few selected clones from me , growers and clubs to cross with a neville haze male . the goal will be reached improving the high , for example the amnesia haze cut hy-pro seeds from cordoba is a great plant,strong haze smell, great yelds ,but i hate the high, my hope crossing them will be to obtain something in the middle or maybe with best of both. now i'm struggling with future offspring ,i have so many seeds and strains i don't know where to start, first because i don't want to plant hundreds of seeds , second because i would like to maintain this game little , for me only but same time doing it in most professional way. how many seeds do you use to test newer crosses ?

 

[OnceUpon]

I appreciate the in depth response.
especially the emphasis on testing the "stable line with as many different stable lines as possible."..
getting the best possible results at this stage will very much determine the direction afterwards.

also, i like the idea of choosing the hybrids that are "showing the traits you like from your stable line" rather than the plants that are not expressing as much of the stable line in the outcross. i assume this will make things easier later?

improving/adding positive traits (structure, size, effect) to an indica that works well outdoors in my climate(bc canada) is the basis for my plan... sadly, most of the great local varieties around are all pretty much mixed and quite unstable. great lines that need preservation. but not predictable to work with... so, even the stable line is yet to be decided.
I will likely choose the one of these local lines that is most stable... at least for finishing time. and look elsewhere for another "stable" indica line to work with at the same time and play with 2 similar breeding projects. (or at least in the first stages)

sativa is likely to be from you. panama & Tikal were lovely. the malawi's effect wasnt as "groovy"... but there were so many great things about the way it grew, in this kind of situation a bit of selection could probably find a nice one

as for testing, i dont have the space for large numbers. but i have time. hoping through clone saving, re vegging, and freezing pollen and sharing that over time i am able to make nice selections. and hope something works. get lucky maybe, or choose a male thats a dud and toss out hundreds of seeds and start over. all in the fun. thanks for the help!

 

[Dr.King]

Dubi, that post alone shows why you are the best breeder on this site. You keep me learning everyday man. As always thanks again .