Heritability of Intersex Traits

[GMT]

Hi Tom,

Personally I would always want any females that showed male pollen sacks to be removed from breeding stock. How far you go in order to "make" them do that is clearly debatable but I find it hard to imagine the production of male reproductive organs on a female to be beneficial to our requirements. I understand that not all offspring from a hermie (term used for simplicity in this situation) will hermie, or that not all offspring from a particular mother who doesn't wont either, however evolution shows us that to exist, we draw upon what existed before us. To me it stands to reason that over time, using plants that don't hermie will produce offspring that doesn't hermie. And that's using natural selection the way nature does. ie. by phenotypic selection alone. A lioness doesn't select a lion because his last set of cubs were big, but rather because he is big. Selecting the average from a population or open pollination does more to preserve the genepool, but less to aid evolution of the gene pool. A certain amount of selection is always needed. I personally feel that's why its preferable to add hermies to the list of no nos.

 

[Tom Hill]

Hi GMT,

I agree, mostly. The lioness may be selecting by way of phenotypic evaluation, but ultimately genotypes are in the drivers seat. Just as the lioness may chose a male masking deleterious recessives, so might the plant breeder who goes about breeding solely by way of phenotypic evaluation. Two plants, (A) and (B). Plant (A) has the potency, flavor, yield, meets goals in every way, and has no intersexed tendencies under extensive testing. Plant (B) also meets the goals but shows intersexed tendencies under extensive testing. In the course of breeding, plant (A) proves in her progeny to have a genotype with low fitness and our desired traits are not recovered, furthermore reveals intersexed tendencies in her progeny as well though she masked them herself. Plant (B) in her progeny proves to have higher fitness, our desired traits are recovered, and also reveals no problematic intersexed tendencies under more normal environmental conditions. Plant (B) has a much higher breeding value than plant (A). So, let's be careful not to screw the pooch like the lioness did (or the guy who put all of his money on plant (A)), we are smarter than that. I think that there are many folks who are saying this or that should never be done or used etc, but they are overlooking the fact that scenarios similar to the above are extremely common, nay, expected more often than not, in the course of breeding. -Tom

 

[GMT]

So what you are saying, is that the biggest strongest fastest lions to have ever lived, may well have been the ancestors of lion families that have died out due to their offspring having been inferior to the offspring of more avergae families. That's fascinating. I don't have the experience to have made those obsevations for myself yet, and was pretty much relying on evolution's "survival of the fittest" being a little simpler than it now seems to be. It seems counter intuitive at first, but I guess it makes sense on reflection. I guess the fact that there is movement from the average increases the probability of further movements from the average in future generations too, and not always beneficial movements.
Thanks Tom

 

[GreenintheThumb]

Stupid lioness, I bet she doesn't know a single genetic marker

 

[englishrick]

Only recently have I been imposing this added selection parameter, as I said, I've observed no problematic intersexed expression in the past and saw no reason for it. All the latest selections are being subjected to this. However, I expect to see no measurable short-term improvement with this added light-stress parameter, I have the feeling that it is relatively superfluous over the short term. The reason being as stated before is that throughout the history of plant breeding (as well as my own observations) the correlation between phenotypic value and genotypic value tends to be quite low. Mass selection, where individual plants are selected or rejected based on phenotypic value, has proven to be a very slow and inefficient breeding scheme regarding short-term progress.

The percentages of plants with intersexed traits observed under stress is very much line dependent, large differences among lines. In my experience, the background genotype of the population is much more influential than the phenotype of the individual parent in regards to these types of traits. IE, just because you find a "true female" in a population of Thai genetics with a history of intersexed traits, don't expect quick progress towards ridding the population of that trait by using it as a parent.

PS- Hi Kopite. -T

hay tom

have you considered "The Colour Rendering Index" [CRI] as selection parameter?.

 

[Tom Hill]

I believe I know where you're heading with that Rick but give me a quick example. -T

 

[englishrick]

when i chat about bulbs i allwasy talk aboutt CRI,,,,"The Colour Rendering Index" its a scale that measures the clarity and quality of a light source,,,,

the sun puts out the 100 on the CRI,,,, a HPS tyipcialy dosent offer over more than 22 on the CRI,,,,,,,,,id say thats a added selection parameter,,,HPS is Missing alot of eliments IMO,,,

 

[Tom Hill]

Rick, yeah, that's what I thought you meant.

You are absolutely right, in the last 30+ years, we have added a new selection parameter - performance under indoor cultivation. This is the macro-environment in which the vast majority of selections are performed -in and for- these days.

We need to have an idea of the target environment when developing varieties because values will change in different environments. IE, The narrow-leaf tropical will outperform (in the tropics) the broad-leafed Hash plant from the north and vice versa.

So here's the target environment - red-orange light, unnatural photoperiods, light leaks, big swings in nutrient availability, novice gardeners etc. If this sounds ridiculous it is meant to, but it is also the reality.

In the course of breeding lines for this macro-environment, we might find ourselves tossing 10-20% of candidates that would be outstanding in other environments. I can't see how it would not lead to an added deficit of heterozygous plants, removing some of the buffer when re-introducing said lines to new environments.

It all concerns me enough to stop and think before I go along my merry way, and make sure that I am storing seed that has not been subjected to these types of selections. When all is said and done and these draconian laws are a thing of the past, I'd like our grandchildren to be able to grow some cannabis in the backyard -from Havana to Alaska- and not have it be all played out and driven to the ground via indoor selections. -Tom

 

[englishrick]

Rick, yeah, that's what I thought you meant.

You are absolutely right, in the last 30+ years, we have added a new selection parameter - performance under indoor cultivation. This is the macro-environment in which the vast majority of selections are performed -in and for- these days.

hay tom,,,

yeh man,,,HPS is a 20 year old system,,,i personaly use high preasure MH bulbs now an all sorts of suplermental light whenever possible; but i can understand WHY our selection parameters have gone crazy,,,,,,,its not allways possible to grow in perfect conditions,,,,,imo some seeds should be for Novice growers and some for Expert`s Only!, this gives a sence of difficulty and even stress tollerence,,,,,,,and as you explain below "Target Enviroments" are extreemly important

We need to have an idea of the target environment when developing varieties because values will change in different environments. IE, The narrow-leaf tropical will outperform (in the tropics) the broad-leafed Hash plant from the north and vice versa.

yeh,,"The Target Enviroment"......peeps will grow ,,any way any how,,,,,,

i can only speke for myself ,,i want the Expert Range....il remove any odd phenos through my own selection,,,,i aint gona bitch if some plants express
intersexed traits in MY enviroment,,,,,an from what i gather a propper AfghanLine classicly shows intersexed traits from time to time,,no?,,,,makin seeds for stability is 1 thing but makin seeds for "ALLROUND ENVIROMENTS" is intence,,,,

Indoor,Outdoor,Easy,Medium,Hard,,,,,,,,sounds like Deep Chunck is gona be bullet proff

So here's the target environment - red-orange light, unnatural photoperiods, light leaks, big swings in nutrient availability, novice gardeners etc. If this sounds ridiculous it is meant to, but it is also the reality.

In the course of breeding lines for this macro-environment, we might find ourselves tossing 10-20% of candidates that would be outstanding in other environments. I can't see how it would not lead to an added deficit of heterozygous plants, removing some of the buffer when re-introducing said lines to new environments.

i can emagine some growers rely are THAT BAD?,,,,,a Novice is something no1 wants to be,,,,,an its not long beffore most of us improve....not all growers need bullet profe seeds,,,,,,,,,,,please give us a choice to grow something that aint designed for S&M growers..

It all concerns me enough to stop and think before I go along my merry way, and make sure that I am storing seed that has not been subjected to these types of selections. When all is said and done and these draconian laws are a thing of the past, I'd like our grandchildren to be able to grow some cannabis in the backyard -from Havana to Alaska- and not have it be all played out and driven to the ground via indoor selections. -Tom

i bet your grand kids get a wickid lil box ,,,with about 1000000 seeds inside,, an a note sayin,,,,,,,, "dear childern,,i intrust the future to you,,, lesson 1 Darwin, lesson 2 Allard",,,,,,

 

[Jones]

.

 

[elmanito]

hay tom,,,

yeh man,,,HPS is a 20 year old system,,,i personaly use high preasure MH bulbs now an all sorts of suplermental light whenever possible; but i can understand WHY our selection parameters have gone crazy,,,,,,,its not allways possible to grow in perfect conditions,,,,,imo some seeds should be for Novice growers and some for Expert`s Only!, this gives a sence of difficulty and even stress tollerence,,,,,,,and as you explain below "Target Enviroments" are extreemly important

A new light system is tested at this moment to see if it is a replacement for HPS, MH
This light contains also UV A,B,C.Its good for the highland varieties

http://www.youtube.com/watch?v=DE6yLuI1NPM

Namaste

 

[englishrick]

http://www.hydrofarm.com/pb_detail.php?itemid=9100

hehehe,,,,,your gona love this

 

[elmanito]

I know this kind of lamp, but does it contain UV???
NASA is also testing the plasma light.An agricultural university in NL has done a test with plasma with very good results on cucumber.
What i see at this moment with MH plasma light is much better than with other light in terms of quality and would be a good artificial light for breeding.

Namaste

 

[bonecarver_OG]

an other awesome set of post

educational and entertaining

 

[BENJI]

Great thread and discussion what i did notice was all this talk about true females which got me thinking is what about males does the same principal apply with testing males for intersex traits do some people notice with different strains a different percentage of intersex traits amongst males/females i was talking to a very well respected aussie breeder and he said he noticed a higher than normal intersexed ratio among the males from a particular strain but nearly none show up in the female progency,,, i guess what im trying to say is the "INTERSEX" gene the same weather its in a female or male or is this gene different or more profound in a certain strains opposite sex's and which side did the intersex trait come from male or female......?

 

[englishrick]

I know this kind of lamp, but does it contain UV???

no....i wish it did......

hay elmanito......how do you feel about UVB tubes?,,,,,ive never used them,,,,,,

 

[GMT]

Benji, as far as I can see there is nothing to force Muller's Ratchet theory to act equally on both genes. Therefore to my mind, it seems logical to assume hermie traits would differ in the male line to the female line. But that's just theory.

 

[englishrick]

hay benj.........id say yor right!,,,,,,males seem to show a higher % of intersexed inderviduals,,,,,,,,im guessing its because of the Y chronosone de-grading

hay GMT,,,,,,is it possible for the sex chromozones to become inactive and for the Autosome to controle sex expreshion.....

imo ,,,,,,,,epigenic effects are makin our plants express themselves ,,,our current selection parameters are exagerating stress tollerence issues,,,,,,

the "Target Enviroment" needs to be defined,,,,,,,,,imo

 

[GMT]

Hi Rick.
hermaphrodites are present as an earlier stage of evolution. Therefore to say that it is caused by the "degeneration" of Y, is actually getting it backwards. The process by which Y "degenerates" is the very process which eliminates the hermaphrodite tendencies. This "degeneration" rather than being what it sounds like, is actually a beneficial process for what we are looking for (which is a subjective value judgement, which I know some people, for instance Tom, would disagree with me on). In practice both sides of the arguement are correct for different desires of the grower. You may have seen a couple of us talk about the ratchet theory. This theory attempts to explain why and how the Y chromosome becomes the Y chromosome which is "missing" one leg of the X. This lost info is what causes the plant to lose its intersex traits as it is the instructions to make female pistils etc that is "lost" from its set of instructions. What happens is as the dna is rearranging itself at the point of creating the haploid cells to be passed on, some of the info is moved from one chromosome to the one next to it, leaving less info in the first and shortening its relative length. There are other theories, however to me, this is the easiest to immagine happening. So as Y becomes shorter and contains less info (is that really degeneration or is that evolution?) the plants become more stable in their relative sexual assignments. Now some of the info may be lost altogether and some simply moved. This is where Tom and I differ in our opinions. To guys like Tom who are looking to preserve the plant in its truest state, its like turning wolves into yorkshire terriers. However to guys like me, it prevents your crop from being ruined. Tom may say its ruined before you plant the seeds I dont know, it isn't right for me to talk for Tom really. Thereagain, I am an indoor pollen chucker with very limited space and far less experience, and Tom has all the experience and space he needs. So really its a case of different horses for different courses and levels of horsemanship.
The point is that the degeneration of Y is not so much a degeneration as an alteration which changes its purpose of existence. And it is a natural evolution which our own species has almost completed (very few hermaphroditic people being born these days though it does still happen). Some of us want to speed this process up, some are concerned that doing that may cause us to lose out on important dna sequences. I figure so long as both camps are safe and secure and working away, everyone gets the best of both worlds and can choose what they grow depending on their circumstances.
Epigenetics is an important factor to bring into this discussion though you are right. As it may well be that a plant which doesn't show its intersex traits, may well contain them, but have them (rather than removed from the Y (or Y's info moved from the X)) those genes may well be silinced by rna, which is the epigenetic effects of its own experiences while forming as a seed and while being grown by the grower. So we not only have to consider the dna but also the evolution of rna. If a plant is exposed to a light leek, its isnt so much a case of "does the genes contain hermie genes?" but rather "will the rna under these circumstances, switch the intersex genes on?".
I agree entirely that it all depends on your target environment.

 

[englishrick]

wow,,,,i just dribbled on the laptop...better wipe that sh1t up,,,,

amazing post GMT,,,,,

i pray 1 day il soak up 10% of what you have.....

im gona read that again,,,,,,excuse me