Photos of germinating seeds

[Inyan]

F1 crosses can achieve an novel phenotypical expression that is not seen in either parent. With this said, that novel expression in an F1 cross can be rare with many crosses and can require thousands of seedlings to achieve. A blending of traits, rather than a new phenotypical expression, is more likely, is most often seen in the F2 cross between two hybrid seedlings as many genes are quantitative rather than qualitative in nature. This is why an F2 x F2 cross is seen as more productive if it can be done. You may actually create a new species that can freely breed, or breed best, with other hybrids like itself. This addition of genes may allow for new expressions as one species may not have a recessive form of a particular gene or set of genes while the other species does. Or, you may find that while neither species has a recessive gene for a particular trait, that the crossing allows one set of genes to act as the recessive or co-dominant gene in a newly formed cross. Utilizing the pollen donor type from the original species cross to the F1 hybrid will tend to give you better results, but you should not exclude the possibility of using the pollen from the maternal species as well. Lastly, your F1 hybrid may produce variable pollen that allows you to fertilize both species parents much more effectively than either original crosses. You have to realize though that every pollen grain is a unique assortment of the pollen grain genes from each parent which will mean that many seedlings from such a cross could very well appear to be a pure species cross simply as the pollen selected to grow faster and achieve fertilization first by the maternal plant is the pollen that is carrying the most similar set of genes to that particular species. This is why techniques such as minimal pollination are often done in conjunction with normal pollination techniques, cut style techniques, etc. With minimal pollination of 8-20 grains of pollen for instance you can rest assured that a higher percentage of variable pollen genetics makes it to the ovary if it is going to make it at all. Still, minimal pollination techniques don't do you much good if only 1 in 200 pollen grains is going to make it anyway. This is another reason for making many cross pollination attempts using various styles and methods. Your F1 seedlings are going to be the most interesting in what they can produce via attempts utilizing them as a pollen donor back to both sets of parent species, to each other, and as recipients of pollen from both sets of pollen donor species, or perhaps they will have a higher chance of accepting yet another foreign pollen from a completely unrelated species, etc. This takes time, plenty of flowers, and of course an ability to think outside of the box and an ability to not get disappointed or discouraged if your pods result in nothing more than callous tissue or an aborted pod. The idea is to keep trying until you get that lucky variable pollen genetics to work for you in cases like this. Its all about the numbers of attempts as each pollen grain is like a person, each one is unique and different. Keep good notes and hope for the best. Keep tabs on all future seedlings produced from such attempts as successful crosses are not always apparent in the first set of seedlings. In the end, you may have to take up tissue culture and embryo rescue as a hobby if you become sorely disappointed with your results. If your still not having any luck after a few years of trying take try different pollens and moms from the same species or different ones as each is unique. Still no luck, try a researching polyethylene glycol solutions and high calcium dilutions. Protoplast fusion is something I've been researching and while it doesn't sound that hard, requires a bit more lab equipment then what I currently have and of course much trial and error at the start as with everything. Still, the idea of Trichocereus + Lophophora = Trichophora might be nice. Still, 44 chromosomes and not what your after as your looking at 22 chromosome type crosses. You could in theory try anther culture though to reduce the chromosome count back to 22 chromosomes and grow those resulting hybrids up to try more useful hybrids.

[mutant]

Ehhhmmm, a much easier question....

Some seeds seem to be weaker and some stronger, judging from the seedling apprearance and growth rate. I have also heard that stronger seedlings are best to choose to graft , what about the weaker ones? Will they evolve into weaker smaller cacti [and that is IF they survive] if they remain ungrafted?

I suppose that since grafting with embryos, variegated, strange seedlings are possible which are by nature weaker, then every graft with a weak but 'normal' nevertheless seedling has fair success rates.... Are there any special notes for special / weak / etc seedling - grafts?

[btw I have tricho seedlings in mind, but I will be doing others as well]

[Inyan]

Grafting weak scions onto strong stock is a given if you want to increase the chances of the weaker one growing to maturity and possibly breeding with that weaker seedling. Now, why would you want to introduce a weaker set of genetics into your hybridizing program? If your into variegates, crested forms, etc. then you have a reason to do this. If your into hybrids, you have a reason to do this. Should your goal be to continue variegated type crosses or crested forms you will find that you have better luck with grafting to keep your diversity up and to attain new seedlings and so on with those same characteristics. Now, if your goal is to create faster growing, taller, wider, more heavily flowering strains or hybrids then you will eventually want to start selecting for those traits from your hybrids. As a general rule of thumb, you do what you can to keep those first few generations of impossible crosses going until you can breed those genetics back into both parent gene pools to acquire the added advantage you hope to have achieved by your initial crosses. The weaker the scion is the more important it is that the stock is actively growing as the tissues between the two plants will be growing together and most of the strength will be coming from the stock. Albeit, with seedlings this is already the case and does not need to be stated. The weaker the scion though the more important it is to get an early graft started and the more important it is that you keep the humidity up. I've found that some grafts will not work without creating a humidity tent and others will succumb to bacteria, fungus, etc. when optimal temperatures and humidity are kept up. Take variegated Trichocereus pachanoi for instance. It is much more prone to root rot in general and must be treated similar to an ariocarpus if left on its own roots. Grafted to a nice stock plant of the same species that is not variegated though and it soon takes off in growth and no more worries about root rot. I know other experts will have more detailed information for you, but I'll leave this in place and hope they go into more depth when they arrive.

[mutant]

Wow I got more answers than I expected! That partly explains [or anyway excuses] some failures of my seedling grafts that were all done in freshly rooted pere's. I find that pere tips start growing almost immediately when put in soil, but their roots won't be developed enough for some time...

I admit my motives for the qustion are much more humble than hybridisation. I only happen to have 20something seedlings of various trichs, and just want to grow as many of them as I can to see in first hand any possible differences. I already lost a somewhat yellowing bridge graft attempt, and want to play with the best odds in my next attempts. Nevertheless, I do have more seeds of various cacti, and plan to do another sowing soon.

The weaker the scion though the more important it is to get an early graft started and the more important it is that you keep the humidity up.

by early graft you mean in days or couple of weeks time??

I suspect that for such attempts [very young seedlings] to have good success rate one must have first determined/planned a well funtioning humidity dome and airing schedule. [and maybe some preventional fungicide at hand?]