Modérateur : Groupe [SB] & [SR]
On est bien daccordsauf que beaucoup de dj travaillent plus avec du vinyl , mais avec du bon CD
la féminisée c'est le mcdo de la gastronomie française ^^la feminisee se serait un peu le macdo de la graine ?
Bob faudra vraiment que tu comprennes un jour que si y'avait pas des petits gars comme toi qui en achetaient, les breeders ne feraient pas de féminisées !En fait c'est pas les feminisées qu'il faut diaboliser, c'est le travail des breeders et leur tendance à lancer de nouvelles variétés fem sans version reg et ça j'avoue que c'est la merde
Bien sur que oui !!et vi ! d'ailleur la vrai question est
"ya til une reelle différence niveau génétique entre une feminisée et une femelle ?"
Sam, il faudrait vraiment que tu essayes d'approfondir tes connaissances en génétique, cela te permettrait de comprendre tout ce qui t'échappe, plutôt que de te borner à jouer l'avocat du diableet pourquoi des feminisés rendraient une ligné stérile? desoler mais tu prend une plante issu de seed feminisé , tu secoue un male au dessus , ça donne des graines , donc partant de la , je pige pas ce qu il veut dire.
apres le coup de poser des probleme pour créer de nouvelle variété , desoler mais fem ou polyhibride regulier donne le meme résultat.
Je sens que personne ne lira ce pavé, mais c'est bien dommage, comment débattre au sujet de la génétique du cannabis, si on n'en connait même pas les bases ?Cannabis has a haploid number of 1n=10; its somatic number is 2n=20. Some researchers have counted 2n=18 + (XX) or (YY). In the male plants, 9 pairs of the normal genomic pairs of chromosomes are equal in size, and the tenth pair (XY) consists of one chromosome about the same size as the members of the other pairs, plus one much larger sex chromosome. Heteromorphic pairs of chromosomes have been observed in monoecious strains of cannabis. (14, 15)
K. Hirata concluded that (x) has a higher male tendency than (X), and that (y) has a higher female tendency than (Y). The (X) has a net female tendency, and (Y) has a net male tendency. The male tendency in (Y) overbalances the female tendency in (X) so that a heterogeneous (XY) male is normally male, and a (XX) plant is normally female. Female hemp genes are (XX), (XXX), and (XXXX). The (XXXY) and (XXY) individuals are female or female intersexes. The males are (XY), (XYY), and (XXYY).
The Sengbusch Classification system defines five degrees of monoecious forms: (1) 80-90% male flowers; (2) 60-70% male flowers; (3) 40-50% male flowers; (4) 10-30% male flowers; (5) less than 10% male flowers. The second and third degrees types are considered ideal for monoecious cultivation
Studies by Warmke and Zhatov revealed that the normal sex ratio for diploids (2n) is nearly 1:1, but tetraploids (4n) form a new class (XXXY) and develop about 7.5 females:1 male, plus female-hermaphrodites. The XXXX is female; XXXY is female-hermaphroditic; XYYY is male-hermaphroditic, and YYYY is male. The XY determination of sex does not account, however, for the development of some monoecious strains. Seemingly, the sexual expression of hemp can be controlled by some other gene set(s) influencing different aspects of flowering. Environmental conditions also can overpower the genetic expression of Cannabis' gender, especially in the final stages of flower production. (20-23)
From the research conducted by McPhee, von Sengbusch and Hoffman we know that when a monoecious hemp plant pollinates a dioecious female the offspring (F1) consists of over 90% of females, or 3-5% of monoecious plants bearing mainly female flowers and only 3-4% of true males. This small number of males however is sufficient to ensure adequate pollination of the crop. As the stand consists mainly of seed-bearing (female and dioecious) plants, with the same habit, we called it unisexual hemp. Such a stand yields 60-80% more seeds than a dioecious cultivar. The seed produced on this stand (F2) is used as sowing seed for fibre production. We called this cultivar Uniko-B. It is, in fact, a 'single cross' between Kompolti and Fibromon, but it is the F2 generation which is commercialized. Von Sengbusch and Hoffman described the phenomenon, but they did not think of its practical use... we make the cross between Kompolti and Fibromon on a surface of 5 hectares; this yields 2500 kg of F1 seed. The F1 seed is sown on a surface of 500 hectares, yielding 400,000 kg of F2 seed, which is used to sow 3,000-3,500 hectares of fibre hemp.
"Unisexuality also can be used to exploit the effect of heterosis [hybrid vigor] which occurs when Chinese and European (Kompolti) cultivars are crossed. This heterosis can increase stem yield by 8-15%. to be able to cross two cultivars we have to construct a female parent which is 'male sterile'. A unisexual F1 can be used as such. In order to obtain a unisexual Chinese line we used Fibrimon as the donor, which was backcrossed many times until we obtained a monoecious line with a Chinese habit. We crossed this line with the original dioecious Chinese cultivar to obtain a unisexual Chinese F1... [with] an unsurpassed seed yield potential of up to 1,500-1,600 kg per hectare...
In 1978, however, Stepanov reported on "The ineffectiveness of the back-crossing method selection of hemp for heterosis":
"In back crossings the additive effect of the genes predominates. The selection of the characters controlled by the additive genes leads to the homozygous increase of the population and reduced vitality of the plants. The repeated crossings of the heterozygous hybrid plants with the parental form homozygous for the recessive gene increases the quota of the genes of the latter. It results in the intermediate type of inheritance for all the elements of the backcross hybrid productivity...
"The use of the inbreeding method in hemp breeding... as a method of differentiating a heterogenous population and selection of the most valuable biotypes is the first stage in the creation of controlled heterosis. The investigated hemp cultivars were heterozygotic not only for numerous characters but also for combining ability, which even after 5-fold self-pollination was manifested in different families to a different degree. The magnitude of combining ability of the line was higher, the more strongly it was differentiated genotypically relative to all other lines. In the first stages of practical breeding, the inbreeding methods can be used in creating heterotic variety-line hybrids.
"Heritability of main productivity elements and their anticipated gain in populations of various types of intervarietal hemp hybrids... plant height and fiber content in a stem, are highly-heritable irrespective of the crossing types. Low heritability is typical of such integral characters, as the number and weight of seeds from one plant; they are modified depending on the growth conditions. The higher the heritability coefficient, the greater the genetic gain of characters. Other conditions being equal, selection is more efficient. From the theoretical view point the expected gain of all the productivity elements at simple and complex intervarietal crossing is considerably higher than at reciprocal ones." (43-45)
M.A. Fedin reported concerning "The efficacy of gametocides inducing male sterility" in 1984:
"The heterotic breeding method is more effective than the methods used before. The breeding process is shorter. It is possible to produce the necessary quantity of hybrid seeds in a shorter period." (46)
K. Goncharova and N. Migal observed "Deviations in meiosis in four sources of hemp male sterility":
"Microsporocytes dying off, migration of the chromosomes beyond the borders of the spindle division in the metaphase and anaphase, lagging chromosomes in the anaphase, formation of the micronuclei in the telophase, and asynchronous division of the microsporocytes." (47)
N.D. Migal also studied the inheritance of the length of the vegetative period:
"Families with different intervals between ripening of male and female plants were revealed in dioecious hemp. This permits breeding for simultaneously ripening forms by selecting families with a minimum interval." (48)
Migal's research also revealed another useful finding:
"The dwarfs of monoecious hemp represent a recessive mutation form valuable for studying peculiarities of natural mutagenesis and changes in the development of sex expression." (49)
The intersexual form of male sterility in the plants of monoecious hemp is characterized by a complete lack of pollen. It is inherited by the next posterity through the monofactorial type of inheritance, which makes it possible to use it as a maternal form in the process of hybridization.
The transition of male to female flowers can be accomplished by wounding the infloresences of male plants. The anther lobes will transform into ovules. The earlier this process begins, the more normal is the development of female flowers. Bisexual flowers also are obtained. (50)
and this lil tidbit i found =)
a post by heirloomseeds
heirloom_seeds
a law unto myself
Registered: Feb 2004
Location:
Posts: 398 interesting read.
not wanting to argue that males have no place but the Y chromosome is only needed to make more males, a male has nothing to offer breeders of drug cultivars that cannot be gotton using sex reversed females as a pollen source.
however there are plants XX that appear to be males - phenotypic expression.
with so much said concerning hemp breeding using monoecious X dioecious , i hope anyone reading doesnot start to think that this type of crossing is acceptable for drug cultivars.
according to hypothesis raised by hoffman(1947,1952 )the sex of the flowers is more important than the habit. it follows from this that the feminized males areXY forms, like normal males, and the masculanixed females are completely identical to normal females, thus being XX forms. hoffman though it was very likely that the inhertianc of sex depends not only on gonosomes, but also to a great extent on the autosomes. this was confirmed by cytological studies........
........the extremely interesting and surprising resultsobtained in these hybridization experiments again show that the inhertiance of the sex and habit of monoecious and intersexual forms cannot be satisfactorily explained by the XY mechanism valid for dioecious hemp.....
like hoffman (1961 ), migal suggests the presence of sexual genes on autosomes as well as on gonosomes. in the inhertiance of of monoecism he distinguishes between the purely female phenotype segregating from the monoecious populations and the dioecious female genotype proved to exist in crossing experiments.
sex is geneticaly determined in cannabis but the expression can be modified by several factors. due to its dioecious nature, cannabis has been used as a test model in physiological experimentsinvestigating the role of phytohormones on sex expression9e.g., galoch, 1978; mohan ram and sett, 1982; nigam, varkey, and rueben, 1981).
as a more or less unintended result of this research,various chemical treatments have been published that enable selfing of male and female cannabis genotypes as well as the mutual crossing of individuals of the same sex. as far as the author knows, only recently author knows, only recently has chemicaly induced sex-reversal found practical application in cannabis breeding9 de meijer, personal communication, 1997). - advances in hemp research, chapter 8 genetic improvement: conventional approaches- ivan bocsa, paolo ranalli editor
anyone wanting to know more about genes that affect phenotypic sex expression might want to read up on the plant hormone ethylene, when a plant begings flowering ethylene production is increased along with giberellins. giberellins may function as a male plant hormone and the are responsible for the stretch that occurs in flowering . the lack of ethylene is shown to induce male flower formation.
crossing monoecious ( hermies) with dieocious is fine for hemp breeding , but it is undesirable for drug cultivars. this can result in XX plants that are phenotypicly males and XY males that appear to be females, trouble in future generations.
this is from a chart in advances. while monoecious forms will revert to dioecism if left to them selves. it is too slow for us and requires huge numbers.
2nd generation ratio of male plants 1: 100,00.................
3rd generation ratio of male plants 1: 10,000..................
5th generation ratio of males plants 1:100..................
selfing is a step for quickly creating ibls to be used in the production of hybrids, not a end in its self.
i think gynoecious breeding is the wave of the future, saving time, space and less waste since no males are used. no reson that after creating an ibl though selfing that those ibls cannot be crossed to males making for standard seeds, if one has suitable males.
i,m not against traditional crossing using male to female crossing, if one has good males go for it. i find it as easy to have all usable females though.
i would rather have x number of usable females rather than x - 50%( males ), but i wonder how many people breeding use an equal number of males to females. i bet not many if any. i see many using 1 : 1 mating's and that maybe fine for terminal production - clonal propagation for production, but not so good for future breeding.
i believe most seed lots sold are intended for production not breeding.
my mind is empty i seem to be at a loss to express my thoughts better, than this at this time. so if i make no sense thats my excuse. if i was feeling better i am sure i could say more better understood.
heirloom
heirloom_seeds
a law unto myself
Registered: Feb 2004
Location:
Posts: 398 i believe Shipperke once said that in females ( humans) 1 x is shut off, i am guessing the same may be true with plants.
i don't know enough to say for sure but ajust guessing that the X is needed to function.
if there are YY males its only a matter of time untill some one reports that they have found one . the method you gave would be the first step in proving that. i think a lab test would be in order if one suspected they had a YY male, as proof.
So then you infer that the genes that controls ethylene production are only active in the female. Males may carry these genes but may have other genes supressing their expression. This is just a shot in the dark though.
i don't think its as straight forward as that.
intersex males - hermies may produce potent buds , i think due to increased ethylene production.
heres something from advances on sex types ;
according to hypothesis raised by hoffman(1947,1952 )the sex of the flowers is more important than the habit. it follows from this that the feminized males areXY forms, like normal males, and the masculanixed females are completely identical to normal females, thus being XX forms. hoffman though it was very likely that the inhertianc of sex depends not only on gonosomes, but also to a great extent on the autosomes. this was confirmed by cytological studies........
........the extremely interesting and surprising resultsobtained in these hybridization experiments again show that the inhertiance of the sex and habit of monoecious and intersexual forms cannot be satisfactorily explained by the XY mechanism valid for dioecious hemp.....
like hoffman (1961 ), migal suggests the presence of sexual genes on autosomes as well as on gonosomes. in the inhertiance of of monoecism he distinguishes between the purely female phenotype segregating from the monoecious populations and the dioecious female genotype proved to exist in crossing experiments.
sex is geneticaly determined in cannabis but the expression can be modified by several factors. due to its dioecious nature, cannabis has been used as a test model in physiological experimentsinvestigating the role of phytohormones on sex expression(e.g., galoch, 1978; mohan ram and sett, 1982; nigam, varkey, and rueben, 1981).
as a more or less unintended result of this research,various chemical treatments have been published that enable selfing of male and female cannabis genotypes as well as the mutual crossing of individuals of the same sex. as far as the author knows, only recently author knows, only recently has chemicaly induced sex-reversal found practical application in cannabis breeding9 de meijer, personal communication, 1997). - advances in hemp research, chapter 8 genetic improvement: conventional approaches- ivan bocsa, paolo ranalli editor
in advances they list 6 types of intersex forms for females and 6 for males. giving a total of 12 sex types. interestling enough some plants that form late hermie flowers are the last type f these have been used to create early feminized seeds which gave feminized seeds a bad reputation.
here are the 6 female types:
1. intersexual forms with female habit:
a. bearing exclusively female flowers = normal dioecious female
b. bearing female and androgynous flowers = androgynous female
c.bearing female ,androgynous and male flowers = androgynous monoecious
d. bearing male and female flowers = monoecious
e.bearing exclusively androgynous flowers = androgynous form belonging to female habit series; and
f.feminized male plant bearing exclusively male flowers.( dioicus feminized male )
all six intersexual forms are also found for plants with male habit, giving a total of 12 possible intersexual forms. the last type f may also produce a small number of female and androgynous flowers toward the end of vegatation period. - advances in hemp research.
androgynous means staminate and pistillate flowers in the same inflorescence.
it seems obvious that ethylene or a lack of plays a role in hermies too.
type 6 - f could be mistaken for a male unless lab tests are done, to prove it is really XX though it appears to be XY .
this ^^ is something i have been meaning to talk to you about and get your veiw on. i think this could have serious implications on a breeding project, i imagine recombination nightmares in later generations happening.
i meant to mention the trouble several years ago that nirvana seeds had with their feminized lines with reports of all males, probably due to using an intersex plant - a hermie.
i think this shows us why we must cull all hermies.
là j'ai lu et je 
faut pas te tracasser LeMarcel"fausses femelles" (ou femelles "intersexe", mieux connues sous le nom de "féminisées") = (XXXY) ou (XXY)
le marché est comme il est , et ça ni toi ni moi n y pouvons riens.
d'après vous, quel pourcentage de cultivateur ne jure que par les regulars ? 20% ? 40 %?le marche est ce que nous en faisons
c biens ce que je dit j y peu rien, mes achats de seeds fem represente a peinne 5% de mes achats de seeds.et non, et c'est ce que dit shantibaba
le marche est ce que nous en faisons
la demande encourage l'offre
th seed vend ses graines reg plus cher que ses féminisés, ca commence .les graines régulieres resteront toujours dispos sur le marché, la chose qui risque d arriver c est en effet une augmentation de leur tarifs,
Ninjah a écrit :et pourquoi des feminisés rendraient une ligné stérile?
Allez .. Mettons la Skywalker DP ou n'importe quelle autre strain qui est plus dispo qu'en fem . Ben courage pour trouver un pur male
nana.... skywalker papa m'en reste 3 en stock.... skywalker be back 
j'commence une nouvelle serie star war 
pas pu en avoir plus) 