Is there a conclusive case of polyploids in cannabis? Everyone calls fasciation or whorled phyllotaxy polyploids, but that’s incorrect. Plus, in the vast majority of plant species, polyploids cannot be bred with, so that point is moot.
Chemically induced for sure, or at least it's some old wives bro science lore of old. I think I read it in Mel Frank's book, Marijuana Growers Guide, some 25 years ago, about how colchicine could induce tetraploidy in Cannabis.
Copied and pasted this from wikipedia
Botanical use
Since
chromosome segregation is driven by microtubules, colchicine is also used for inducing
polyploidy in plant cells during
cellular division by inhibiting
chromosome segregation during
meiosis; half the resulting
gametes, therefore, contain no chromosomes, while the other half contains double the usual number of chromosomes (i.e.,
diploidinstead of
haploid, as gametes usually are), and lead to embryos with double the usual number of chromosomes (i.e.,
tetraploid instead of diploid). While this would be fatal in most higher animal cells, in plant cells it is not only usually well tolerated, but also frequently results in larger, hardier, faster-growing, and in general more desirable plants than the normally diploid parents; for this reason, this type of genetic manipulation is frequently used in breeding plants commercially.
When such a tetraploid plant is crossed with a diploid plant, the
triploid offspring are usually
sterile (unable to produce
fertile seeds or
spores), although many triploids can be
propagated vegetatively. Growers of
annual triploid plants not readily propagated must buy fresh seed from a supplier each year. Many sterile triploid plants, including some
tree and
shrubs, are becoming increasingly valued in
horticulture and
landscaping because they do not become
invasive species. In certain species, colchicine-induced triploidy has been used to create "seedless" fruit, such as seedless
watermelons (
Citrullus lanatus). Since most triploids do not produce pollen themselves, such plants usually require
cross-pollination with a diploid parent to induce fruit production.
Colchicine's ability to induce polyploidy can be also exploited to render infertile hybrids fertile, for example in breeding
triticale (× Triticosecale) from
wheat (Triticum spp.) and
rye (Secale cereale). Wheat is typically tetraploid and rye diploid, with their triploid hybrid infertile; treatment of triploid triticale with colchicine gives fertile
hexaploid triticale.
When used to induce
polyploidy in plants, colchicine cream is usually applied to a growth point of the plant, such as an apical tip, shoot, or sucker. Also, seeds can be presoaked in a colchicine solution before planting. Another way to induce polyploidy is to chop off the tops of plants and carefully examine the regenerating lateral shoots and suckers to see if any look different.
[40] If no visual difference is evident,
flow cytometry can be used for analysis.
Doubling of plant chromosome numbers also occurs spontaneously in nature, with many familiar plants being fertile
polyploids.
[41] Natural hybridization between fertile parental plants of different levels of polyploidy can produce new plants at an intermediate level, such as a triploid produced by crossing between a diploid and a tetraploid, or a hexaploid produced by crossing between a tetraploid and an
octoploid.
Not taking sides, but have you noticed? There are never any 'likes' under either of you cats' posts when you get into the extremely tired and played out flame fests.
Please take this for what it means, and concentrate on other topics, where you both produce worthwhile posts. Muchos grassyass.
Its fitting with Gu's Wild West Series, that there be a good saloon fight.
I do like a good western.
Cheers 
