without directing things to homzygote genepairs,,, this can happen
__A_ a
A AA Aa
a Aa aa
never seen aa beffore now
__A_ a
A AA Aa
a Aa aa
never seen aa beffore now
hutch said:Homozygous
In a living organism, having two identical alleles for a given trait...eg Aa,,, Individuals homozygous for a trait always breed true; that is, they produce offspring that resemble them in appearance when bred with a genetically similar individual; inbred varieties or species are homozygous for almost all traits. Recessive alleles are only expressed in the homozygous condition. Heterozygous organisms have two different alleles for a given trait.
by hutch said:Homozygous
In a living organism, having two identical alleles for a given trait...eg AA is Homozygote....Aa is Heterozygote ,,, Individuals homozygous for a trait always breed true; that is, they produce offspring that resemble them in appearance when bred with a genetically similar individual; inbred varieties or species are homozygous for almost all traits. Recessive alleles are only expressed in the homozygous condition. Heterozygous organisms have two different alleles for a given trait.
by hutch said:Homozygous
In a living organism, having two identical alleles for a given trait...eg AA is Homozygote....Aa is Heterozygote ,,, Individuals homozygous for a trait always breed true; that is, they produce offspring that resemble them in appearance when bred with a genetically similar individual; inbred varieties or species are homozygous for almost all traits. Recessive alleles are only expressed in the homozygous condition. Heterozygous organisms have two different alleles for a given trait.
The DEA is probably laughing at how poorly we have been handling the gene pool; All the inbreeding and erosion, the small populations, the ignorance/stoner logic, the greed and the carelessness...theyre probably ALLOWING worldwide seed sales to continue because they know its more harmful to drug cannabis than stopping it.
Quote:
Quote:
Originally Posted by Jones View Post
Open pollination favours early maturing plants. A seedline maintained by OP without selection drifts quite a bit. Genes of late maturing plants are lost or at least become uncommon.
This guy nailed it on the head! OP favours the early flowering males.
it would only favour early maturing flowers if all the females had the same flowering period,which in a true outdoor OP I doubt. it would also depend on many enviromental factors, which you see with landraces they have usually evolved/adapted to their enviroment via natural selection.
So for genetic diversity natural selection is still above breeder supplemented. and the reverse true for pure lines.
As stated previously the only way to attain 99% diversity is via 2000 plants etc.
Look up population genetics.
it helps if you use all of what I stated and not just a bit to suit, that said in the rye example where does it give the numbers used? it does prove regeneration is needed, as to the 2000 for dioecious to attain diversity, this number is used because of this:Quote:
Originally Posted by URUK View Post
As stated previously the only way to attain 99% diversity is via 2000 plants etc.
Look up population genetics.
You mean like this?
Molecular studies on genetic integrity of open-pollinating species...
http://www.springerlink.com/content/nw2149xuxydjmcv6/
Quote:
The genetic integrity of six accessions represented by 14 sub-populations of the open-pollinating species rye (Secale cereale L.) was investigated. Seeds available from a herbarium collection (first regeneration) and from the cold store (most recent regeneration) were multiplied two to fourteen times and fingerprinted using microsatellite markers. Four accessions had significantly different allele frequencies. These were multiplied seven to thirteen times. Nearly 50% of the alleles discovered in the original samples were not found in the material present in the cold store. However alleles were detected in the most recently propagated sub-populations, that were not observed in the investigated plants of the original one. The change in allele frequencies is a continuous process. Reasons for the occurrence of genetic changes and consequences for managing open pollinating species maintained in ex situ genebanks are discussed.
See, this is what happens if people follow blindly statements like:
Quote:
...the only way to attain 99% diversity is via 2000 plants etc.
While obviously even plant numbers encountered in rye fields don't suffice to do that.
http://hempworld.com/Hemp-CyberFarm_com/htms/research_orgzs/iha/ihagenetic.htmlThe primary goal of the germplasm preservation project is the conservation of the entire gene pool of each accession. It is very important that the population size is large enough to ensure that as many of the genes as possible within the accession's gene pool are reproduced in the resultant seed. We set a minimum limit of 1,000 plants for monoecious varieties, and 2,000 plants for dioecious ones. This assures that 99% of the gene pool will be reproduced with each reproduction (Crossa et al. 1993). Unfortunately the seed reserves of many of the accessions consisted of less than 1,000 viable seeds making our goal impossible to achieve. The secondary goal is to reproduce the accessions in sufficient quantities to maintain a reserve for future reproductions and distribute seed to researchers worldwide. We have set a minimum limit of 300 grams of seed for long term storage and later reproductions. Seeds can be released to the research community only if more than this amount is held by the VIR. Three hundred grams is approximately 15,000 seeds and will allow the following three storage regimes:
1.) 5,000 seeds stored at an ambient temperature of 15 degrees Celsius and moisture content of about 10%, in an active collection for reproduction,
2.) 5,000 seeds kept at 4-6 degrees Celsius and 7% moisture content in refrigerated medium-term storage, and
3.) 5,000 seeds archived in a reserve collection at -20 degrees Celsius and 6% moisture in frozen long-term storage.
About 40 percent of the seed accessions are now stored in refrigerated or frozen storage.
I think Clarke has proved what is achievable with 2000 plants
A.Börner's email and fax number can be found in the linked article.....in the rye example where does it give the numbers used?
Really, when and how did he do that?
By quoting some theoretical statistical model?
Or did he do what the rye guys did and actually looked at the genetic integrity on the molecular level?
edit:
A.Börner's email and fax number can be found in the linked article.
Just ask him if you assume those genebank guys are also speed closet hacks and only grew a handful of plants somewhere in a backyard and don't know about the statistical models involved.