????Natural Feminization process????

[zamalito]

Someone else also asked me a similar question about if a male that produces a few female flowers is ok to breed with. I'm sure many of you read the djshort article that mentions how self seeding males can be useful for breeding and protect against hermaphroditism in future generation. Now I have no definite explanation on exactly why some male dominant hermaphrodites can self seed and most cannot. I'd believe it also has something to do with the occurance of a yy chromosome set. When an xy male has the same gene as forfor female hermaphroditism it expresses a few female flowers. However when it does this a natural mechanism to prevent the ocurrance of a yy offspring the female flowers show sterility. If a male can produce fertile seeds then it could also produce a yy chromosomed offspring and that would be damaging to the survival of the line.

I have used seed bearing males before in breeding and while they do tend to produce male dominant hermaphrodites (85% and higher male flowers) there is also much less occurance in future generations of female dominant hermaphrodites or sex reversal. Lines bred from seed bearing males chromosomally speaking (hehe) become feminized in that they are only posessing x chromosomes. Over a one or two more generations you select males that display no female flowers and you have a line that has a high m/f ratio and shows very little intersexed traits since a mostly male xx is recessive to a mostly female and some male xx the appearance of a mostly male trait means the male has only genes for being xx and the herm locus is homozygous (the same gene on both pairs) for the male dominant to completely male trait. This also allows for very high female ratios since a situation is created where a female expression is actually dominant to male expression.

 

[Guest]

FIRST If you look at the shape of a X it is sort of the shape of an Y with something elece. so its not feminist propaganda, is just not true

Ok so if a male that turns hermi is used to breed with then you will get a higher female to male ratio.

this makes cents to me.

so if a female that turns hermi is used you should get a higer male to female ratio allso.

Well i got nine plants to see what happens with them.


some male dominant hermaphrodites can self seed and most cannot this is called Gametophytic or self-incompatibility in plants is a widespread mechanism preventing self-fertilization and the ensuing inbreeding depression. The evolution of inbreeding depression allows for a partial purging of nearly recessive lethal mutations by selfing, and accounting for pollen limitation etc. Individual variation in selfing rates may lead to individual variation in genetic load, such that lineages that practice more self-fertilization may have lower genetic load then those that primarily outcross from the exposure to deleterious recessives to selection. If there are genetic loci that modify the selfing rate (for example, loci that influence the separation or timing of female and male reproductive fertility), then loci determining rates of self-fertilization may become associated with loci influencing genetic load.(wikipedia)


Hey i grew out 9 packs of purple#1 with 3 females in the do maby there were breed with hermi moms

 

[Guest]

So in theory

1- male dominant hermaphrodites means that the female chromosome is more prevalent and there would be a higher female/male ratio.

2- female dominant hermaphrodites means that the male chromosome is more Prevalent and there would be a higher male/female ratio.


I would rather have 100 males go hermi than one of my females any day.

 

[Guest]

 

[zamalito]

Hey bajan,

That's nuts that you only got 3 females out of 90 seeds. It could however be explained by the scenario I'd previously mentioned. Since like I said at the hermaphrodite locus the gene for non intersexed expression tends to be dominant the mother could have been heterozygous and had a recessive gene for male dominant expression along with the dominant gene for purely female expression. Meanwhile like the female the male would've been xx on the sex chromosome but at the hermaphrodite locus is double gened for male dominant expression. This would've produced 75% of the offspring with mostly male expression.
I have doubts that the mechanism preventing male on male self fertilization is there to prevent inbreeding depression. I've grown out male dominant intersexed plants that would not produce seed despite having multiple males releasing pollen grouped fairly close together. The plants weren't just sterile to their own pollen but other males also. Personally I've never seen any evidence that any females I've grown were only sterile to their own own pollen. I don't want to say just because I haven't seen it doesn't mean it doesn't happen, nothing could be more wrong. Though I really haven't seen anything to make me think a trait to cause sterility to only self seeding is what causes the majority of male dominant hermis to have sterility in their female flowers. (Sorry that last sentence was pretty unclear). I could see the possibility of maybe some ovum not growing into a full seed if the ovum inherited a y chromosome from both the ovum and pollen since yy organisms almost always die very soon after fertilization. Thus after fertilization that ovum would be sterile. The problem with this theory is that a yy combination only occurs 25% of the time in an xy to xy fertilization so that could only explain 25% of the flowers being sterile. This is pretty far from 100% of the female flowers being sterile among 95% of males dominant plants.

I don't know why you think I'm incorrect about saying y chromosomes have an incomplete genetic makeup. This is from what I always understood to be a proven fact. YY organisms always die almost immediately after fertilization. Doubly y chomosome fertilizations accidentally occurs in both plants and animals and from what I understand they always die.

 

[Evolution]

by outsourcing the pollen from the female pollen donor to a straight female, you are ensuring the seedbearing female is herm-free resulting in feminized seeds of all female chromosomes, but recessive herm trait... if a herm pollinates itself then you have herm trait everywhere and herm herm herm.

dalat being an old landrace sativa has a recessive herm trait already, and that is how that seed was made and fell to the ground, and sprouted and grew and hermed like its parent, and so the seeds will be 99% herm at this point, NOT 99% female. comprende?

'by outsourcing the pollen from the female pollen donor to a straight female'--how can this be done, i.e the clone of the mother is the same genetically...it sounds as those you are suggesting they are different, perhaps a temporal or environmentally triggered gene expression? am i understanding correctly?


thanks in advance for any elucidating replies...