High Male Ratio - Bad luck, strain or enviornment?

bcell said:

Good debate all opinions respected but I would say birth control pills to increase sex has to be "utter shitte" as well.

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Chromosomal sex determination systems may be an evolutionary consequence of natural selection in favor of dioecy. Sex chromosomes do not appear suddenly in animals or plants. Rather, it is the pair of autosomes bearing the sex determination genes that have evolved specialized features, i.e., the degeneration of the Y chromosome, resulting in heteromorphy that became the hallmark of sex chromosomes. Two major sex chromosome systems have evolved. One is the active Y chromosome system, or the XY system (or ZW in a heterogametic female system), in which females have two of the same kind of sex chromosome (XX), while males have two distinct sex chromosomes (XY). The other is the X-to-autosome (A) balance system, in which the ratio of X:A chromosomes determines sex by an X chromosome counting system and the Y chromosome is dispensable.

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Among the many dioecious plant species, only a few have evolved sex chromosomes (Westergaard, 1958 ; Renner and Ricklefs, 1995 ; Charlesworth and Guttman, 1999 ) (Table 1). As in mammals, some dioecious flowering species have an active-Y system of sex determination with heterogametic males (XY) and homogametic females (XX), such as white campion (Silene latifolia), papaya (Carica papaya), and asparagus (Asparagus officianalis). Several dioecious species have the X: A dosage compensation system for sex determination, for example, sorrel (Rumex) and hops (Humulus). An X-to-autosome ratio of 1.0 or higher results in a female and 0.5 or lower defines a male (Ono, 1935 ; Westergaard, 1958 ), which is similar to the situation in Drosophila and Caenorhabditis elegans (reviewed by Mittwoch, 1996 ). These two sex chromosome systems may reflect two different stages of sex chromosome evolution that will be discussed further in the following sections.

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One of the sexes, usually the male, is heterogametic,
producing two types of gametes and bearing male or
female factors. The other, the female, is homogametic
and gives rise to only one type of gamete bearing the
feminizing factors (Lou et al. 2002).
Heteromorphic sex chromosomes are rarely found
in angiosperms but have been reported in a number of
plant species including Rumex, Cannabis, Humulus,
and Silene (Parker 1990, Charles et al. 1997). In dioecious
Silene, males are the heterogametic sex (XY)
and females are homogametic (XX) (Westergaard
1948). As is the case in mammals, Silene has an active-
Y system of sex determination, with dominant
male factors and female suppressing factors mapping
to the Y chromosome. The X chromosome appears to
be essentia1 in both males and females because only
monoploid females can be obtained by in vitro techniques
(Ye et al. 1991). Application of hormones, including
GA, auxins, and cytokinins, does not result in
sex conversion.

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Environmental sex determination is known to occur in a variety of species.[73] Many researchers have suggested that sex in Cannabis is determined or strongly influenced by environmental factors.[62] Ainsworth reviews that treatment with auxin and ethylene have feminizing effects, and that treatment with cytokinins and gibberellins have masculinizing effects.[56] It has been reported that sex can be reversed in Cannabis using chemical treatment.[74] A PCR-based method for the detection of female-associated DNA polymorphisms by genotyping has been developed.[75]

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coconaut said:

To the peeps arguing for environmental factors; how would you explain feminized seeds?

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Zealious said:

as a matter of fact I can gurantee the main reason u had this happen is that u are using a yellow light instead of a blue spectrum light.. use 6500k daylight flourescents.. I get 70% fems

You can get as high as 90%

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kopite said:

reversed or selfed "true" females hence they are still genetically female but grow balls (stamens) hence the resulting seed is female... XX x XX instead of XY x XX

Kopite

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coconaut said:

Not quite what I meant.
Some people in this thread are arguing that environmental factors determine the sex of the plant.
I was pointing out that if the resulting seed (XX x XX) could still be influenced by environmental factors then feminized seeds would be total BS, which they are not.
Environmental factors determining sex of cannabis plants is the real BS.

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kopite said:

you have had a man with a degree in genetics tell you what is what in chimera and you ignore it!!

Kopite

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kopite said:

Utter shite plain and simple, things have moved on from K. Hirata... all you are doing is masquerading the sex ie its transient you havn't change it... just like when you reverse a plant etc.. bad info is bad info please do not spread it.

Kopite

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Zealious said:

That article ur referencing is not specifically about cannabis. they are talking about sex chromosomes in plants yet they have not been found in cannabis.

the article starts with the first paragraph entitled.

ABSTRACT

as in one mans theory. it is not scientific fact.

there is no way that these plants are exhibiting the normal dioecious sexing like mamals....

its not as simple as X and Y . there is more to it then science can explain.. Unless u show me a documented study with scientific evidence that proves environment does not effect the sex of this particular plant... or evidence that cannibis has a x and y chrom and sex is pre determined.. then sir u are the one full of shite.

Or maybe its just ur opinion

We are entitled to our opinions.. no need to start bashing or handing out neg rep.

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That article ur referencing is not specifically about cannabis. they are talking about sex chromosomes in plants yet they have not been found in cannabis.

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Male-associated DNA sequences were analyzed in a dioecious plant, Cannabis sativa L. (family: Moraceae), which is known to have sex chromosomes.

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Zealious said:

wow lets give neg rep for posting my opinion and point of view.. I was just stating my opinion here.. and what i posted was direct from wikipedia.. sounds like a lot of scientist agree that eviroment is a huge factor...

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so when u take a XX x XX true female.. make it grow. balls.. why is it that u can get a chance of getting a Male seed. female seed and hermie seed

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