WTF is w/feminized genetics,

[darwinsbulldog]

Good point Darwin, the problem with info here on the forums is people have to be anonymous so it's very hard to know who to listen to.

I have ruined a lot of plants through following bogus advice over the years so now I'm very sceptical. This thread is a great example of knowing who to listen to being very problematic.

The other problem I have is knowing what questions to ask to find the answers I need. For example, I doubt googling 'sexual expression in cannabis sativa' will find me a simple, easy to understand answer!

yeah that's it mate, often if they have huge respect, i will take their advice with much less hesitation than if they don't, obviously they earned the respect by not spewing bullshit so it says something, but at the end of the day i try and double check things via google or other sources too to be sure, also it just helps reinforce my understanding if i look it up and read about it a few times initially. what has really shocked me about this forum is the accessibility to those guys at the top, breeders like tom hill, shantibaba, esben, have really helped me as of late whenever i've had questions and for that i'm really grateful, and hope they don't mind my badgering haha.

umm if you go to the breeders section on this page, and look at the sticky threads, there're some great ones that have a shit load of info about cannabis sex expression. only issue is pretty much all research has been done on hemp. though they're such closely related species i'd say it'd be exactly the same biology between the two species. i'll link you to the pages... but a lot of the links to journal articles don't work because you need to be a member of the journal to download them. being at uni i just go through their site and they let me download all the papers for free, so if you want any specific ones you can't get your hands on feel free to ask me and i'll email you them. goes for anyone else on here too, if you need anything just ask friends!

scientific reference bibliography

1.breeding/selection

- Marijuana Botany by R.C. Clarke - http://www.mellowgold.com/grow/mjbotany-removed/

- Factors influencing yeild and quality- http://www.internationalhempassociat.../jiha5107.html

2.pollen/pollenation

3.sex

- Sex linked SSR markers- https://www.icmag.com/ic/showthread.p...422#post853422

- Novel male(specific markers)- https://www.icmag.com/ic/showthread.p...468#post853468

- Molecular biology of dioecious plants- http://aob.oxfordjournals.org/cgi/reprint/86/2/211

- RAPD markers encoding retrotransposable elements are linked to males- https://www.icmag.com/ic/showthread.p...839#post860839

4.Indica

5.Sativa

6.hybrids/crosses

7.cannabinoids

- Quantitive analysis of Cannabinoids- https://www.icmag.com/ic/showthread.p...725#post853752

- DNA polymorphisms in THC- https://www.icmag.com/ic/showthread.p...722#post853722

- Chemotaxonomic analysis of Cannabinoids- http://www.amjbot.org/cgi/content/full/91/6/966

- Inheritence of chemical phenotype- http://www.genetics.org/cgi/reprint/163/1/335

8.selfing/feminizing

9.micropropagation/tissue culture

Plant growth regulator on callus induction- http://www.ib.uj.edu.pl/abc/pdf/47_2/145-151.pdf

Book Reviews: http://www.internationalhempassociat.../jiha6213.html

(thread written up by JLP)

i found about another 30 papers last night too while researching. just gonna have to chug through and read them all now in my spare time haha damn exams! anyway hope that helps guys.

ps sorry for the off topic post.

darwin

 

[englishrick]

hay Raco

good to see you chekin in on us,,,

have i been expalining things to an adequate standard?

 

[Raco]

Cannabis does not have hermaphrodite plants - King Ralph did that to me once Raco - That is an oddity on a monoecious individual from within a subdioecious population

Thx bro
I have to admitt that you´ve changed my mind...and can´t thank you enough for that
But if I was to breed I´d still use males...still old school jeje

The bract ^is from a lebanese "strain" collected in Bekaa Valley in 2005
Hermied indoors,and the tendency would stop when moved outdoors weird uh? heheh

Hola rick,
ask the experts
layman here

 

[Tom Hill]

Hermied indoors,and the tendency would stop when moved outdoors weird uh? heheh

Yeah, a bazillion generations outside then flipped-out indoors, hmm, imagine that.

 

[Raco]

They auto-flower indoors and are normal plants here @ 43ºN,finishing by the end of September ...and no hermies in my limited experience..I´ve never grown more than 3 or 4 of these plants outdoors

 

[englishrick]

hay tom,,,i agree with the "subdioecious" analagy,,,,but am i right to think canna or its ancestors were origonaly hermaphrodite?

 

[darwinsbulldog]

here's a great paper:

Boys and Girls Come Out to Play: The Molecular Biology of Dioecious Plants

Charles Ainsworth+
Plant Molecular Biology Laboratory, Department of Biology Sciences, Imperial College at Wye, Ashford, Kent, TN25 5AH, UK

Received: 14 February 2000 ; Returned for revision: 28 March 2000 . Accepted: 25 April 2000

The majority of the world's flowering plants are hermaphrodite but many of them encourage cross pollination by means of spatial or temporal separation of eggs and pollen, or by genetically-controlled physiological incompatibility. A minority of species has taken the avoidance of self-pollination to its logical conclusion by evolving two distinct and sexually different forms (dioecy). In a very small number of plants, dioecy has been accompanied by the development of sex chromosomes. From the study of the development of male and female flowers of different species it is clear that there is no common underlying mechanism and that sex determination systems leading to dioecy have originated independently many times in evolution. This Botanical Briefing highlights new information from recent molecular approaches in the study of dioecy.Copyright 2000 Annals of Botany Company

http://aob.oxfordjournals.org/cgi/reprint/86/2/211

EDIT: haha looks like englishrick already got the diagram from the paper and posted it way ahead of me apparently mate haha

darwin

 

[darwinsbulldog]

Thx bro
The bract ^is from a lebanese "strain" collected in Bekaa Valley in 2005
Hermied indoors,and the tendency would stop when moved outdoors weird uh? heheh

would that be a result of natural vs unnatural lighting?

 

[freefields]

None of the colleges anywhere near me offer part-time courses in any form of biology. I am looking into going back to school part-time to do an A-level in plant biology, which would be a course starting in September.

I tried that CS applied to the rootzone thing on a couple of seedlings I was gonna throw out. Very quickly it's apparent that CS kills roots, so I guess I'm gonna have to stick to spraying CS onto the leaves. The idea Gerrit suggested of injecting it into the stem sounds interesting, but I don't have a hypodermic at hand.

 

[Raco]

I´d say "yes"...Fact is that the plants kept flowering under 18/6 indoors

 

[darwinsbulldog]

I´d say "yes"...Fact is that the plants kept flowering under 18/6 indoors

but outside it required 12/12 or there abouts?

 

[Raco]

The plants were all started indoors 18/6..vegged for a while and trasplanted outdoors in June..and were harvested by the end of September.behaved like normal early plants here @ 43N

GrassMan´s lebanese plants started from seed outdoors in 2003 (I think)

 

[darwinsbulldog]

nature just loves fucking with us, once you work out the "laws" by which its governed it either shows you you're wrong, or changes them haha

 

[Raco]

nature just loves fucking with us, once you work out the "laws" by which its governed it either shows you you're wrong, or changes them haha

Very true hehe!

 

[freefields]

Seems to me it's not just nature that likes fucking with us.

The last 2 pages just gave me a perfect example to illustrate what I mean.

Cannabis being hermaphrodite or not, well, reading Tom, Raco and Rick's posts on the subject on the last 2 pages just confuses me even more than I was before.

Seems to me that a lot of people who do have in-depth knowledge don't like teaching others, they'd rather 'fuck with us' by making posts that don't teach anything and just confuse the matter.

It really doesn't help those like me who are trying to learn!

 

[freefields]

Found this recent article that I thought might be of interest:

Plant Breeding Breakthrough: Offspring With Genes from Only One Parent

ScienceDaily (Mar. 25, 2010) — A reliable method for producing plants that carry genetic material from only one of their parents has been discovered by plant biologists at UC Davis. The technique, to be published March 25 in the journal Nature, could dramatically speed up the breeding of crop plants for desirable traits.

The discovery came out of a chance observation in the lab that could easily have been written off as an error.

"We were doing completely 'blue skies' research, and we discovered something that is immediately useful," said Simon Chan, assistant professor of plant biology at UC Davis and co-author on the paper.

Like most organisms that reproduce through sex, plants have paired chromosomes, with each parent contributing one chromosome to each pair. Plants and animals with paired chromosomes are called diploid. Their eggs and sperm are haploid, containing only one chromosome from each pair.
Plant breeders want to produce plants that are homozygous -- that carry the same trait on both chromosomes. When such plants are bred, they will pass the trait, such as pest resistance, fruit flavor or drought tolerance, to all of their offspring. But to achieve this, plants usually have to be inbred for several generations to make a plant that will "breed true."

The idea of making a haploid plant with chromosomes from only one parent has been around for decades, Chan said. Haploid plants are immediately homozygous, because they contain only one version of every gene. This produces true-breeding lines instantly, cutting out generations of inbreeding.

Existing techniques to make haploid plants are complicated, require expensive tissue culture and finicky growing conditions for different varieties, and only work with some crop species or varieties. The new method discovered by Chan and postdoctoral scholar Ravi Maruthachalam should work in any plant and does not require tissue culture.

Ravi and Chan were studying a protein called CENH3 in the laboratory plant Arabidopsis thaliana. CENH3 belongs to a group of proteins called histones, which package DNA into chromosomes. Among the histones, CENH3 is found only in the centromere, the part of the chromosome that controls how it is passed to the next generation.

When cells divide, microscopic fibers spread from each end of the cell and attach at the centromeres, then pull the chromosomes apart into new cells. That makes CENH3 essential for life.

Ravi had prepared a modified version of CENH3 tagged with a fluorescent protein, and was trying to breed the genetically modified plants with regular Arabidopsis. According to theory, the cross should have produced offspring containing one mutant gene (from the mother) and one normal gene (from the father). Instead, he got only plants with the normal gene.
"At first we threw them away," Chan said. Then it happened again.
Ravi, who has a master's degree in plant breeding, looked at the plants again and realized that the offspring had only five chromosomes instead of 10, and all from the same parent.

The plants appear to have gone through a process called genome elimination, Chan said. When plants from two different but related species are bred, chromosomes from one of the parents are sometimes eliminated.
Genome elimination is already used to make haploid plants in a few species such as maize and barley. But the new method should be much more widely applicable, Ravi said, because unlike the process for maize and barley, its molecular basis is firmly understood.

"We should be able to create haploid-inducing lines in any crop plant," Ravi said. Once the haploid-inducing lines are created, the technique is easy to use and requires no tissue culture -- breeders could start with seeds. The method would also be useful for scientists trying to study genes in plants, by making it faster to breed genetically pure lines.
After eliminating half the chromosomes, Chan and Ravi had to stimulate the plants to double their remaining chromosomes so that they would have the correct diploid number. Plants with the haploid number of chromosomes are sterile.

The research also casts some interesting light on how species form in plants. CENH3 plays the same crucial role in cell division in all plants and animals. Usually, such important genes are highly conserved -- their DNA is very similar from yeast to whales. But instead, CENH3 is among the fastest-evolving sequences in the genome.

"It may be that centromere differences create barriers to breeding between species," Chan said. Ravi and Chan plan to test this idea by crossing closely-related species.

The work was supported by a grant from the Hellman Family Foundation.

 

[Tom Hill]

I am sorry Freefields,

What I meant was that the term "hermaphrodite" is not the correct one, though it is often (mis)used to describe intersexed (monoecious) cannabis plants. A hermaphrodite plant has individual flowers that contain both male and female parts, but this is not the case with cannabis. Monoecious is the correct term to describe a plant that has both male and female (separate) reproductive parts on the same plant.-T

 

[freefields]

Another article on the same topic:

Haploid Plants through Seeds

Tech ID: 19877 / UC Case 2010-030-0

Abstract

Researchers at the University of California Davis have developed a novel method to produce haploid plants through seeds. This method induces genome elimination (from one parent in a cross) with a precise mutation, rather than by culturing haploid cells or by crossing distantly related plants.

Full Description

Plant breeding relies on screening numerous plants to identify novel, desirable characteristics. Very large numbers of progeny from crosses often must be grown and evaluated over several years in order to select one or a few plants with a desired combination of traits.

Standard breeding of diploid plants often requires screening and back-crossing of a large number of plants to achieve the desired genotype. One solution to the problem of screening large numbers of progeny has been to produce haploid plants, the chromosomes of which can be doubled using colchicine or other means to achieve instantly homozygous, doubled-haploid plants.

With doubled haploid production systems, homozygosity is achieved in one generation. Thus, the breeder can eliminate the numerous cycles of inbreeding necessary to achieve practical levels of homzygosity using conventional methods. Indeed, true homozygosity for all traits is not achievable by conventional breeding methods.

Existing methods of generating haploid plants have numerous disadvantages. Culturing of haploid cells is expensive and laborious, and some species have proven recalcitrant to this technique. Crossing to a distantly related species (wide crosses) causes genome elimination in only a small number of species, and almost always requires embryo rescue in vitro to generate viable plants. Haploid-inducing lines in maize are genetically complex and yield haploids at low efficiency. All current methods may be extremely dependent on genotype. UC Davis researchers have developed a method of inducing haploids in a cross between plants of the same genotype which is based on exploitation of a universal feature of eukaryote chromosomes and which yields haploid plants from seeds.



Applications

This novel technology has multiple applications, including:

* Doubled haploid plants can rapidly create homozygous F2s from a hybrid F1.
* Haploid plants are very useful for genomics because they contain only one version of each gene.
* The method can transfer paternal chromosomes into maternal cytoplasm. Thus, it can create cytoplasmic male sterile lines with a desired genotype in a single step. Currently, generating a cytoplasmic male sterile line with a desirable genotype requires many generations of backcrossing.

Advantages

Using this innovative method:

* Genome elimination can be engineered with a precise molecular change that is not dependent on parental genotype. The gene that is manipulated is found in all eukaryotes and serves a universal function. Thus, haploid plants can be made in species where conventional methods, such as tissue culture of haploid cells and wide crosses, are typically unsuccessful.
* No tissue culture is required. Haploids are produced through seed by simple genetic crosses. This will greatly reduce the cost and labor required for haploid plant production, and make the process accessible to breeders lacking specialized expertise in culturing haploid cells.
* Plants from exactly the same cultivar can be crossed to eliminate one parental genome using a precise genetic change. This greatly simplifies synchronizing flowering time and readiness to cross (relative to the wide cross method of haploid production).
* This method yields haploid plants much more efficiently than current wide crossing protocols, or existing haploid inducers in maize.
* Apart from haploid-inducing lines in maize, this is the only known method of producing haploid plants in which paternal chromosomes are transferred into maternal cytoplasm, generating cytoplasmic male sterile lines with a desired genotype in a single step.

Related Materials

* Ravi M, Chan SW. 2010. Haploid plants produced by centromere-mediated genome elimination. Nature. 464(7288):615-8. - 03/25/2010

PATENT STATUS

* Patent Pending

INVENTORS

* Chan, Simon R.
* Maruthachalam, Ravi

Other Information
Categorized As

* Agriculture & Animal Science
o Plant Traits
o Transgenics
* Biotechnology
o Food
o Industrial/ Energy
* Research Tools
o Other

Related cases

2010-030-0
Keywords

haploid, plant, cultivar, breeding, transgenic
Contact

Randi L. Jenkins/ rljenkins@ucdavis.edu / tel: 530-754-7650 begin_of_the_skype_highlighting 530-754-7650 end_of_the_skype_highlighting. Please reference Tech ID #19877.

Request Additional Information

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Link: http://techtransfer.universityofcali...NCD/19877.html

 

[freefields]

I am sorry Freefields,

What I meant was that the term "hermaphrodite" is not the correct one, though it is often (mis)used to describe intersexed cannabis plants. A hermaphrodite plant has individual flowers that contain both male and female parts, but this is not the case with cannabis.

Oh, don't be sorry Tom, I see what you were getting at now!

'Tis I who should apologise, I thought you were being deliberately obtuse!

I have seen male parts inside a female flower, that pic raco showed of one stamen sticking out of a calyx is something I've seen a few times, mostly in Mexican plants.

I take it when this occurs it is a random mutation and doesn't indicate hermaphrodism?

Thanks for just teaching me something Tom, I always thought hermaphrodite meant equal production of male and female flowers throughout the plant, but I stand corrected.

 

[Tom Hill]

I have seen it before too. But, I think we can all agree that this is not the typical situation in an intersex cannabis plant. I do not recall for example ever even seeing one of those (perfect) flowers that were viable and produced seed, it may have happened somewhere, but no, this is not the usual and therefore I don't think hermaphrodite is the correct term. I don't think we should get hung-up about it, but monoecious or simply intersex are much more correct terms for what we typically refer to as hermies.-T