The inheritance of chemical phenotype in Cannabis

[syk613]

Another interesting article I found on the web enjoy.(a search of a meical research journal database indicates 5000+ artice on cannabis)

 

Authors

de Meijer EP. Bagatta M. Carboni A. Crucitti P. Moliterni VM. Ranalli P. Mandolino G.

 

Institution

HortaPharm B.V., 1075 VS, Amsterdam, The Netherlands.

 

Title

The inheritance of chemical phenotype in Cannabis sativa L.

 

Source

Genetics. 163(1):335-46, 2003 Jan.

 

Abstract

Four crosses were made between inbred Cannabis sativa plants with pure cannabidiol (CBD) and pure Delta-9-tetrahydrocannabinol (THC) chemotypes. All the plants belonging to the F(1)'s were analyzed by gas chromatography for cannabinoid composition and constantly found to have a mixed CBD-THC chemotype. Ten individual F(1) plants were self-fertilized, and 10 inbred F(2) offspring were collected and analyzed. In all cases, a segregation of the three chemotypes (pure CBD, mixed CBD-THC, and pure THC) fitting a 1:2:1 proportion was observed. The CBD/THC ratio was found to be significantly progeny specific and transmitted from each F(1) to the F(2)'s derived from it. A model involving one locus, B, with two alleles, B(D) and B(T), is proposed, with the two alleles being codominant. The mixed chemotypes are interpreted as due to the genotype B(D)/B(T) at the B locus, while the pure-chemotype plants are due to homozygosity at the B locus (either B(D)/B(D) or B(T)/B(T)). It is suggested that such codominance is due to the codification by the two alleles for different isoforms of the same synthase, having different specificity for the conversion of the common precursor cannabigerol into CBD or THC, respectively. The F(2) segregating groups were used in a bulk segregant analysis of the pooled DNAs for screening RAPD primers; three chemotype-associated markers are described, one of which has been transformed in a sequence-characterized amplified region (SCAR) marker and shows tight linkage to the chemotype and codominance.

[Luke Skywalker]

So THC or CBD production is a simple dominance reaction in plants? And all phenos, regardless of race, are capable of expression of pure CBD / THC-CBD Mix/ pure THC in a 1/2/1ratio?

 

Geez, seems a little too simple to me. I would have thought the productions levels of thc and cbd were also related highly to time of harvest.... , not just genetic expression. Not to mention growing condtions generally...

 

Most interesting....

[syk613]

Geez, seems a little too simple to me. I would have thought the productions levels of thc and cbd were also related highly to time of harvest.... , not just genetic expression. Not to mention growing condtions generally...

 

 

Yeah luke this is an abstract of a paper that is readily available the whole version may even be on the net for more info on the grow conditions I am sure it would all be in the methods section or a ref outling the method used would be in the paper. And these results would probably depend on genetics and environment like all phenotyic expression of a genotype.

[Guest Babybear]

I never thought canibis could be so complecatied , simperfie this into terms some Not as knolagesable ppl could c

 

But genictcs are interesting its scaray to me the shit sientis could do with canabisif they could , weed that has certian potenceys in some areas narrow it down to just head stone an so on..

[syk613]

Ok i thought I would add a small glossary for this article.

 

Allele: one of several forms of a gene occupying a given locus on a chromosone

Locus: position on a chromosone at which the gene for a particular trait resides,locus can be occupiedby any one of the allelesfor the gene

codominant: both alleles contribute to the phenotype, neither prevails over the other in a dominant recessive manner.

phenotype:appearance or other characteristics of an organism, resulting from the interaction of genetics and environment.

linkage refers to the tendency of genes to be inherited together as a result of their position on the same chromosone

[kaliking]

I always thought light response and end of season changes would make the biggest change in THC/Cbd factor.

Makes me think that growing pot as an agricultualist is fading and growing Pot as a Sceintist is gonna be the new thing.

Maybe mixing, cross breding and inbreding strains isnt the answer, I need to pick up on the sceintific stuff so i can grow me 100% Thc Mj plant.

 

Interesting article syk613, does this result mean that all F1s are mixed thc/cbd, and all F2's have pure thc and cbd, but also mixed cbd and thc.

Makes me try to think to much.

 

KK

[syk613]

I must admit it has been a while since I have done any significant reading on genetics in relation to the global picture traits, phenotypes etc my reading is more along the lines of the molecular scale so I am better able to answer questions relating to the 2nd half of the paper I know Luke skywalker has the force on his side in these matters as is indicated in his concise description of this abstract so perhaps he may be better qualified to answer your question

I think the impt factor here is that they were all known chemotypes before they were crossed to form f1 (pure cbd/thc as outlined above) then the f1 were mixed chemo and these were self-fert (ie inbreed to itself)allowing the segregation of genes to occur by recombination and what the findings suggest is that the genes controlling CBD THC are v.close together during recombination events(ie the same locus) when cells divide (mitosis or meiosis) and in a stable inbreed strain with different chemotypes and under the right cond this means that a breeder will be able to select or produce lineages with pure or mixed chemotypes becuase of the way these traitsare inherited. , but I may very wrong any comments from ppl would always be appreciated and this really only shows why this happens as is obvious from the 1st sentence where they start the expt with pure chemotype plants. so obviously grows at HortaPharm B.V., 1075 VS, Amsterdam, The Netherlands. know howto do it already.

[pipeman]

all I want to know is, will the shit get you high?

[syk613]

does a bear shit in the woods ? What kinda high you want thc based or cbd based or both its your call now pipeman, grown to order the way of the future?

[pipeman]

I'll have three of everything please