Hi all
it seems that many people have biased ideas of feminized seeds, sex reverse techniques, evolution of genome and biodiversity.
Many methods are now available to masculinize (or feminize) cannabis plants without using any hormones but by using metal salts and ions. In that case reversion produces female or male flower with
viable gametes (I don't know about Nevil's techniques using plant hormones).
The use of theses techniques can be very usefull for breeding purposes.
When people talk about feminized seeds, they immidiatly think of a good hybrid, that was taken for sex reversion to be then sleft polinated to produce feminized seeds and sold as femized seeds of this hybride.
In that case it is sure that you will have plants with less vigor and fragrance and higher letality: this is called imbreeding depression.
It is not due to feminisation, it is just due to the fact that you've inbred a highly allogamous crop (the same happens with onions).
Using sex reversion techniques can help produce real inbredlines (true inbred lines don't exist in dioique cannabis but this is quite logical as it is intrinsically linked to the biology of the plant (a plant needs to be herma or monoique to be able to breed with itself).
the production of real inbreed lines will lead to the production of real hybrids (and not the pseudo hybrides currently sold). this is a major point for wathever crop you breed (onion in my case).
also the male of the species carries across things that is beneficial to the over all health of the spices long turn it aids the plant spices being cannabis in environmental changes and also helps purge mutations i mean there's more positives using real males mate.
This is totally faulse male plants don't have more beneficial traits than female it just depends on the genes.
What is importante is diversity of the genetic base. The unique thing a male is going to give that no female will be able to give is the Y chromosome (in other words it gives the ability to become a male, that's it).
You say that mutations must be purged, it's the contrary that needs to be done
genetic mutations is the base of evolution , what you mean is that lethal mutations, and disadvantagous traits need to be taken away, this is done by the selection process of elimination of the bad ones and by self polinisation.
Selfpolinisation make your ratio of homozygosity rise, lethal mutations are usually recessive; by selfing you help these traits to become homozygote and so to express, the plants were the lethal trait is expressed die (most of the time they don't even germinate), like that you take out the mutation provoking this death.
this is also why you have lower germination if selfpolinated lines. (I hope that I'm explaining that in a easy way..).
The loss of biodiversity is a very different problem, this is more due to the illegal aspect of the crop, but people tend to forget the biodiversty of hemp which must be looked at as part of the germplasme for breeding drug strains.
the only thing that would be a big problem if only feminised plants came to exist on earth would be the loss of the Y chromosome; sex reversion must be used in breeding programes not for an end product.
I do agree that not enought studies have been done on that mechanisms of sex expression in cannabis needs to be more studies (many scientific articles are available on the subject, see:
www.googlescholar.com)
The big problem is that no regulation is done in the cannabis industry, it is very much underground, people are readdy to buy 10€ one seed of cannabis

(and one plant can produce 3000 seeds very easily...) and the people in charge of the breeding are not career breeders with the scientific background needed. 3 years to produce a new hybrid???, what a joke! even the easiest crops need at least 7 years, homogeneity is very bad (some beter than others) and varieties are not distinguishable anymore, You can't be sure to buy good quality seeds, germination is not even guarantied....... this is incredible when compared to the legal seed industry.
This is the real problem,not feminised seeds. If real breeders were in charge of the companies sex revers techniques would be more wisely introduced into the breeding programs as well as biotechnologies.
it seem that you (hempy) look breeding as a bad thing, you must not oppose breeding and loss of diversity (in some case it can be true) but diversity is the gaz for breeding to work,the two are intrinsically linked.
one problem is that modern breeding is done using a very narrow genetic base this is why everything tastes and look the same, new sources must be used.
If selecting for shorter flowering periods and higher yield have induced loss of traits this is because it has been done in a amateur way, with not enough plants and to few and easy traits.
Many things still has to be done, fortunatly the new generation is coming ...!!


cheers
Bonbolos