Breeding/pollination question...

[gtarman]

Hey all.

So I was wondering if somebody could enlighten me in regards to plant breeding, and specifically cacti breeding if it's any different (can't imagine why it would be?).

Specifically, I'd like to know what kind of influences the staminate and pistillate parents of plants have on the traits of the offspring?

I mean - what would be the difference between (cactus 1) x (cactus 2), as opposed to (cactus 2) x (cactus 1)?

Is there some kind of tendency for the offspring to be more like the pistillate parent than the staminate? Or does it vary and depend on the traits in question?

[Stillman]

All depends on genetics and how varied the genetics of cross is. Certain traits will be dominant certain traits will be recessive there may be co-dominant traits which is cool. Generally we can assume the progeny will be more like the mother plant in the first cross. If an F2 cross is made god knows, thats when it gets interesting.

[gtarman]

^^ cool! What's an F2 cross by the way? I'm still trying to find a good book on plant breeding that's straightforward to understand :-s

[Jox]

You have raised an interesting question mate, I will be very keen to read the that answers of the more experienced cacti breeders.

I crossed A.myriostima five rib with A.myriostigma four rib last spring, I did the cross both ways to three different flushes of flowers all in the intent of seeing which cross would produce more four rib seedlings, I planted 35 seeds of each cross of kept them separate, the results of my little experiment 67 seed in total germinated & are still going well, it turned out the seeds produced from the pollen put from the four rib onto the five rib gave me one four rib offspring & the seeds produce from the opposite cross gave me exactly the same result, one four ribbed offspring.So my results in cross pollinating two of the same species that had different traits made little differences in the out come.

I look forward to hear what people say about cross pollinating different species & hope to give this a go myself in the next year or so .

Cheers

Jox

[theuserformallyknownasd00d]

R C Clarke wrote a swell book on breeding out favourite herb, cannabis botany I it's name I think. Anyways a look at this book should help ya'll as its applicable aross the board

[Sallubrious]

I had that book about 25 years ago, I think it was Marijuana Botany.

It's a very good place to start, but if you went to year 10 you really should have covered most of it in science.

http://anthro.palomar.edu/mendel/mendel_1.htm

The fundamentals were documented by Gregor Mendel in the 1860's

Some plants and animals show a few deviations from the basic rules, but if you intend breed anything you really need to know the basic rules, it shouldn't take much longer than 15-20 minutes to become well versed in the fundamentals. Some of the nuances will fascinate you for years.

Edited September 1, 2013 by SallyD

[Stillman]

Sally D the progeny from the initial cross is then recrossed producing a f2 progeny ie fist cross f1, f2, f3 etc at some point it should stabalise and some form cultivar that breeds fairly true should be produced. Obviously to get to that point you are gonna produce alot of plants and not all are going to be equal. Certain traits will be focused on in particular line crosses to help stabilise any trait which is desired this is called selective breeding. This is a slow and tedious process, hence why there is so much interest in genomics and genetic modification of plants. Using GM removes the variable, specific genes and alleles can be "impregnated" for want of a better word without the other 12500 base pairs threatening to fuck up traits we already have and want..

Jox look up mendalian 3:1 ratio example Your cross in the same species both ways is interesting, at a f1 cross you are seeing a strong dominance ratio which is kind of expected, as you do not see alot of 4 ribs out there in comparison to 5s. Your 4 rib is recessive your 5 is dominant. Five ribs is being produced alot more due to dominance now what you need to do is cross the progeny and see what you sort of real ratio you get I would think it will be 3:1 either way.

 

 

Edited September 1, 2013 by Stillman

[Stillman]

Example of recessive genetics in a f2 progeny of (ss02 xss01)x (ss02 xss01) got from Zelly, these are possibly my favourite seeds at the moment.

[Bigred]

^^^^^^ Mendelian is my fucking hero

[Stillman]

Jox if you cross two recessive 4 rib f1 offspring then your 4 rib ratio should be much better. subsequent crosses of 4 ribs of f2 and then f3 will be even better.. that or produce some sort of lethal gene like albinism or mutation which is what we all want anyway lol.

Edited September 1, 2013 by Stillman

[Sallubrious]

You can also fix traits by backcrossing the F1 to the parent, to create a BC1 offspring with a similar genetic makeup to the parent it's backcrossed with. Backcrossing is common shortcut used by breeders that can skip several generations of hybridisation.

As stillman said the 4 rib trait is more than likely a recessive gene so you might have limited success with that in this instance.

The important thing is that document all your work.

[Yeti101]

The important thing is that document all your work.

Indeed. Mendel kept meticulous records as I recall. Lost of discussions about cross-breeding pollination going on a the moment - I was just thinking about this for Acacias last night.

[Jox]

Thanks for you examples Stillman & Sally D , it is very good to read what you have both wrote as this is the conclusion I had come to. To greater the chances of producing four rib A.myriostigma's is to cross the two F2 four ribs I got & also like Sally pointed out cross them back over the F1 four ribbed parent.

I am mostly looking forward to see the results of crossing them back over with the F1 four ribbed parent to see the ratio of four ribbed youngsters, as one of the F2 will be getting cross with what was its mother & the other F2 will be getting cross with what was its father so the ratio might start to show more variation & hopefully one way will prove to put out more of the lesser dominate four ribbed traits. Just have to wait a few years for them to get to flowering size . F@#% I love this forum & doing this kind of stuff with my cactus!

Cheers

Jox

[Auxin]

Mendelian genetics, and the punnett square especially, are things every grower should know.

For those that benefit from visual aids there is a cool tutorial on breeding tomatoes [Here]

Page 1 is the most basic, you can then follow the link at the bottom to page 2, then 3

Not all traits are dominant or recessive, thats important to remember. They can be additive or codominant or otherwise messy, too.

Like one time I had a pepper that ripened from green to red and one that ripened from green to yellow, I bred them making a F1 hybrid. As expected they matured from green to red (red is dominant over yellow). Then I selfed those, resulting in the F2 generation. As expected 3/4 were red, but the rest were orangey-gold! It turned out the strong red color from the original red pepper was just covering up a orangey-gold trait that is codominant with red but dominant to yellow. So even the simplest traits that are born out of only one gene pair can throw out unexpected results.

Another thing to keep in mind when breeding is plastid DNA. Long, long ago parasites infected cells, but the parasites and cells started working together and became one organism. In some cases the parasites gave up their DNA, but in some they kept it. Thats how plants got plastids and humans got mitochondria. In hybridization the nuclear DNA gets mixed half and half but all the plastid DNA is from the mother. They are mainly controlling photosynthesis, some plant antioxidants, and energy metabolism (if there are other known plastid based cactus traits I'd love to hear them). So sometimes a trait might follow just the maternal line.

And ultimately there is not always a choice which to use as mother. Pollen might be compatible one way but incompatible another way due to surface signaling molecules or just the pollen from a small flower species not being able to grow down a long flower for fertilization.

If you plan to breed, make sure you have a digital camera with a macro setting. Being able to take ten thousand photos for the cost of two rechargeable AA batteries is a serious benefit to tracking traits without huge volumes of written records.