it is possible with orchids so i think it is possible with cactus. if so is there a 'how to..' link? thanks in advance.
allan
cross breeding with different species
Hi Allan- haven't looked for a hybridization link, but interspecific hybrids are often quite easy among the cacti. A paintbrush and some alcohol to soak it in, in between crosses, and a towel to dry it are all that's needed to try. You can also check out the self steril/self fertile link...if you only have one of each of, for example, Escobaria organensis and Escobaria leei and they both were flowering at the same time and they set seed, you've got yourself a hybrid.
peterb
peterb
Zone 9
Except that plants are sometimes persuaded to self-pollinate when pollen from a foreign plant is applied. I've lost count of the number of times "hybrid" seed has grown into a nice clone of the seed parent with no trace of the supposed pollen donor. You never know what you'll get until you grow it 
--ian
thank you peterb for the info. further to this can you please give me an illustration of the stamen and pistel of the flower. i kind of forgotten what i learn from my biology classpeterb wrote:Hi Allan- haven't looked for a hybridization link, but interspecific hybrids are often quite easy among the cacti. A paintbrush and some alcohol to soak it in, in between crosses, and a towel to dry it are all that's needed to try. You can also check out the self steril/self fertile link...if you only have one of each of, for example, Escobaria organensis and Escobaria leei and they both were flowering at the same time and they set seed, you've got yourself a hybrid.
peterb
thank you iann for this important info.iann wrote:Except that plants are sometimes persuaded to self-pollinate when pollen from a foreign plant is applied. I've lost count of the number of times "hybrid" seed has grown into a nice clone of the seed parent with no trace of the supposed pollen donor. You never know what you'll get until you grow it
if there is such a phenomenon will it work that the recepient plant be rid off its pollen first before being pollinated? also for extra precaution the pollinated plant is sealed with a tape to prevent further pollination. just a thought.
yes they can 
Iann, do you know if pollen is vaible *before* the flower opens? i have tried soem hybrids and i open the flowers early and shield teh stigma and cut the anthers to try and avoid self pollination. or is the sperm ready to go before the stigma?
Iann, do you know if pollen is vaible *before* the flower opens? i have tried soem hybrids and i open the flowers early and shield teh stigma and cut the anthers to try and avoid self pollination. or is the sperm ready to go before the stigma?
Stephen Robert Irwin: 22 February 1962 – 4 September 2006. Rest In Peace.
these are excellent questions, regarding viability of pollen before anthesis etc. I don't know the answers, but suspect it varies by genera or species.
I'm in email correspondence with a guy who is doing some interesting Echinocereus crosses. For example, he's got flowering F1 Echinocereus viridiflorus X pulchellus.
Allan, the stigmas in cactus flowers are very clearly visible in the center of the flower, usually a fairly large structure. The pollen bearing anthers are likewise very accessible and visible.
peterb
I'm in email correspondence with a guy who is doing some interesting Echinocereus crosses. For example, he's got flowering F1 Echinocereus viridiflorus X pulchellus.
Allan, the stigmas in cactus flowers are very clearly visible in the center of the flower, usually a fairly large structure. The pollen bearing anthers are likewise very accessible and visible.
peterb
Zone 9
I just posted a picture that shows the stigma very clearly. Cactus stigmas are divided into several lobes which you can also see, sometimes they are stubby and sometimes very long a thread-like. In this case, the stamens are all coiled up inside the flower, they will open out in a day or two. The second picture in this thread should make it clear where the pollen comes from. In some flowers the stigma may be completely hidden by the stamens of petals, but most cacti display it quite prominently.
Timing of the release of pollen, which is obviously very visible, and of the receptivity of the stigma to pollen, not so visible, varies between species. A common tactic in self-fertile species is for the stigma to be receptive immediately but the pollen is not released for several days. This allows the plant to be cross-pollinated if other plants and a pollinator is around, otherwise it will be self-pollinated. Other plants do it in reverse, or they don't self-pollinate. Still others, with flowers known as cleistogamous because they rarely open, pollinate themselves most of the time and just occasionally open a flower on the off chance of cross-pollination. Sexual reproduction is an expensive and unreliable method, only really valuable in those rare occasions when environmental conditions have changed and the plant needs to adapt, so many plants try to do the majority of their reproduction without involving a second plant. The majority of cacti are obligate out-crossers, they require a second plant for pollination. Examples of self-fertility are sometimes found in individual plants of an otherwise self-infertile species. A few species seem to be more generally self-fertile, and a very few show mainly cleistogamous behaviour.
In plants which are resistant to self-pollination by such methods as toxicity of the stigma or simple physical resistance to the pollen, foreign pollen can induce chemical changes which then allow the plant's own pollen to grow into the stigma. Usually the foreign pollen will fertilise the ovule first, but if the foreign pollen is from a distant species which is not compatible then selfing can often be induced. This is a valuable technique for propagating mutations which arise in only one plant, although a nuisance when you are trying to induce a difficult hybrid.
Cross-fertility of plants is generally controlled chemically, with plants from different species being chemically incompatible. There are also factors such as timing of the flowers, selection of different pollinators, and intriguing things like the tube that a grain of pollen grows when it touches the stigma not being long enough to reach the ovary. Simple geography may be the factor that first comes into play when new species are developing, most pollinators do not travel very far. Because of the different factors preventing species crossing with eachother in the wild, chemical barriers to pollination often don't develop quickly. This allows closely related species to be crossed in cultivation and the hybrids may even be fertile themselves. Wild hybrids which are fertile may go on to develop as a new species, or to merge the two parent species until they are indistinguishable, or they may remain an occasional freak too rare to affect the species as a whole. Hybrids between two different genera are difficult and usually sterile. Hybrids between different plant families are almost unknown and would tend to prompt a rethink on the makeup of the families.
Timing of the release of pollen, which is obviously very visible, and of the receptivity of the stigma to pollen, not so visible, varies between species. A common tactic in self-fertile species is for the stigma to be receptive immediately but the pollen is not released for several days. This allows the plant to be cross-pollinated if other plants and a pollinator is around, otherwise it will be self-pollinated. Other plants do it in reverse, or they don't self-pollinate. Still others, with flowers known as cleistogamous because they rarely open, pollinate themselves most of the time and just occasionally open a flower on the off chance of cross-pollination. Sexual reproduction is an expensive and unreliable method, only really valuable in those rare occasions when environmental conditions have changed and the plant needs to adapt, so many plants try to do the majority of their reproduction without involving a second plant. The majority of cacti are obligate out-crossers, they require a second plant for pollination. Examples of self-fertility are sometimes found in individual plants of an otherwise self-infertile species. A few species seem to be more generally self-fertile, and a very few show mainly cleistogamous behaviour.
In plants which are resistant to self-pollination by such methods as toxicity of the stigma or simple physical resistance to the pollen, foreign pollen can induce chemical changes which then allow the plant's own pollen to grow into the stigma. Usually the foreign pollen will fertilise the ovule first, but if the foreign pollen is from a distant species which is not compatible then selfing can often be induced. This is a valuable technique for propagating mutations which arise in only one plant, although a nuisance when you are trying to induce a difficult hybrid.
Cross-fertility of plants is generally controlled chemically, with plants from different species being chemically incompatible. There are also factors such as timing of the flowers, selection of different pollinators, and intriguing things like the tube that a grain of pollen grows when it touches the stigma not being long enough to reach the ovary. Simple geography may be the factor that first comes into play when new species are developing, most pollinators do not travel very far. Because of the different factors preventing species crossing with eachother in the wild, chemical barriers to pollination often don't develop quickly. This allows closely related species to be crossed in cultivation and the hybrids may even be fertile themselves. Wild hybrids which are fertile may go on to develop as a new species, or to merge the two parent species until they are indistinguishable, or they may remain an occasional freak too rare to affect the species as a whole. Hybrids between two different genera are difficult and usually sterile. Hybrids between different plant families are almost unknown and would tend to prompt a rethink on the makeup of the families.
--ian
Excellent info! so it depends on specie then probably?
have there been any studies on cacti and the "maturation" of the anthers/stigma? my thinking was that if i opened the flowers before they naturally would of (1-2 days early) and cut teh anthers out making it very difficult to get its own pollen on its stigma i would be safe. and if some pollen did manage to get on it, it would still be too early fo rit to be able to work (undeveloped).
does that make any sense? or just depends on the specie? i am trying various mammilaria, turbinicarpus, obregonia and lophophora hybrids....so far without (cross genus) success.
have there been any studies on cacti and the "maturation" of the anthers/stigma? my thinking was that if i opened the flowers before they naturally would of (1-2 days early) and cut teh anthers out making it very difficult to get its own pollen on its stigma i would be safe. and if some pollen did manage to get on it, it would still be too early fo rit to be able to work (undeveloped).
does that make any sense? or just depends on the specie? i am trying various mammilaria, turbinicarpus, obregonia and lophophora hybrids....so far without (cross genus) success.
Stephen Robert Irwin: 22 February 1962 – 4 September 2006. Rest In Peace.
good to know, thanks for all the info
does this occur in "known" self-sterile species as well?Except that plants are sometimes persuaded to self-pollinate when pollen from a foreign plant is applied. I've lost count of the number of times "hybrid" seed has grown into a nice clone of the seed parent with no trace of the supposed pollen donor. You never know what you'll get until you grow it
Stephen Robert Irwin: 22 February 1962 – 4 September 2006. Rest In Peace.