Plant seed…add water…light…and see what happens. Ain't difficult.
Plant seed…add water…light…and see what happens. Ain't difficult.
Sam, whats your thought on males that pop up in self-fertilized lots? I've heard from a few people who have grown decent enough populations that this can happen and that they may even be useful in further breeding.
I've seen this stated several times regarding monoecious hemp as well (could be that everyone is simply citing the original publication on monoecious hemp breeding by von Sengbusch). Basically, monoecious hemp breeding is the same like dioecious breeding just that you do the opposite and select for female 'hermies' and cull the males. There's no biological possibility allowing such a variety to 're-convert' to the dioecious origin. It may be stray pollen (most likely IMO) or, because in hemp breeding one deals with thousands of individuals and not miss a single unwanted plant is nearly impossible, that by coincidence a very few male 'hermies' have been mistaken for monoecious females. Because males usually flower before the females, it's inevitable that they take over after a few generations.
How, apart from stray pollen, it could be possible to find true males in a clone only (pure female) variety I do not know. Maybe just a female gone 'full hermie' or the original female was indeed a 'full hermied' male (which would explain the >90% males in the offspring)?
I've seen this stated several times regarding monoecious hemp as well (could be that everyone is simply citing the original publication on monoecious hemp breeding by von Sengbusch). Basically, monoecious hemp breeding is the same like dioecious breeding just that you do the opposite and select for female 'hermies' and cull the males. There's no biological possibility allowing such a variety to 're-convert' to the dioecious origin. It may be stray pollen (most likely IMO) or, because in hemp breeding one deals with thousands of individuals and not miss a single unwanted plant is nearly impossible, that by coincidence a very few male 'hermies' have been mistaken for monoecious females. Because males usually flower before the females, it's inevitable that they take over after a few generations.
How, apart from stray pollen, it could be possible to find true males in a clone only (pure female) variety I do not know. Maybe just a female gone 'full hermie' or the original female was indeed a 'full hermied' male (which would explain the >90% males in the offspring)?
People do self clones but seldom, as it leads to a loss of vigor and all kinds of negative recessive traits expressing that you do not want.
-SamS
There is an old IT saying, "That's not a bug, that's a feature!".
Deleterious recessive traits can only be culled if they are visible, only if they are expressed. The same population that produces individuals homozygous for deleterious traits will also produce individuals homozygous for desired traits. You just have to sort them out (to me the most challenging obstacle in breeding is the evaluation of individuals for selective purposes, must develop good machine testing).
When I have discussed this with Tom (he is a big proponent of this) I likened it to "breeding weed like it was tomatoes", in other words, treating it like an incrosser, and he agreed that that was his strategy. This requires proper numbers, of course, but I don't think that is a consideration with you?
There is a loss of vigor that is unavoidable with this technique, but is easily mitigated by running several parallel lines derived from the S1, or parallel selfed lines from 2 or more similar clones. Once you have a few parallel lines that are homozygous (for the most part) for the stuff you want, but kinda wimpy vigor-wise, you just cross the lines up. You end up with batches of seed that can be used for production, that produce crops with clone-like homogeneity expressing the desired traits.
Of course the vigor is not as impressive as that seen with wider crosses, but how much vigor do you need? I more concerned with having the exact specific effects I am looking for in a plant, and consistency, than I am with ease of growth.
Thank you for the clarification! I just wasn't sure if this is something like the spinach story where everyone for the last 50 years copied from the first (who mad a bad mistake).Mononecious reverts to dioecious quickly,
I have had this told to me by every hemp breeder I have talked to from Dr Bocsa to the Ukrainians and french breeders J.P. Mathieu, et al. and the Polish and others that maintain monoecious varieties. I know them all.
...
Those from second quality seed (harvested from free-pollinated crops raised from elite seed) comprise, due to natural genetic drift, 15 to 30% males as well as a substantial amount of true-female plants.
...
-SamS
Females are always XX... The X allosome does not 'produce' female flowers, nor does the Y 'produce' male ones; they just regulate genes on the heterosomes which in turn lead to female or male flower production, respectively. AFAIK it's like that with most species and one reason why 'phenotypical sex inversion' is possible.Sengbusch did grow thousands of plants tho. Bosca may have expanded a bit on the theory in his book as well.
If a plant was a "true" xx female wouldn't it be sterile or not be able to produce male flowers? If the plant can self pollinate it self i would assume there is a y autosome somewhere in there and that changes the population genetics of the offspring
I do prefer vigorous plants, and do not want un-vigorous plants.
-SamS
Females are always XX... The X allosome does not 'produce' female flowers, nor does the Y 'produce' male ones; they just regulate genes on the heterosomes which in turn lead to female or male flower production, respectively. AFAIK it's like that with most species and one reason why 'phenotypical sex inversion' is possible.
how many generations do you need to go to start seeing vigor loss and depression?
I can see with hemp lines how in one generation you could see a loss of vigor but if your starting with a polyhybrid drug strain the outcomes might be different.
How would you explain that STS reverts phenotypical sex and that one can breed with such pollen?I thought the Y chromosome was necessary for proper pollen development.
there are degrees of inter-sexed plants that are going to be effected by the environment.
The research that Sengsbusch and Bosca did concluded there are only 1-2% true females or males. I know there are a few clones that when reversed don't seem to drop pollen or set seed, but it seems like 95% on the other hand do. I would assume those are 1st degree herms that you only see with stress, and normally wouldn't see unless the plant was overripe.
Sam encountered herm lines that he worked out so its not far fretched that others released lines that still have that problem, if they looked like the sex they should be and where never stress tested you might never know until down the line, I also believe that the Indians used pull the males but leave intersex plants in the field with to make seeds with, the British wrote an account of it in the late 1800s if I recall