Originally Posted by Sam_Skunkman
Well if it is intersex genetic based DNA test like male and female are it will be easy....
LoL. Nope, it won't, it isn't. So far, we have only a very few male markers. Every 'normal' plant contains at least one X chromosome which is slightly smaller than the Y. As far as the current understanding goes, due the smaller size of the X (which basically fits into the Y), a good part of its genes (called pseud-autosomal region) can be recombined with the Y. Hence the current lack of a female marker. On the other hand, the rathe small part of the Y absent on the X gave only rise to a very few (or is it even just MADC2?) male specific markers which don't 'get lost' after a few generations.
These tests only determine the presence (or absence) of a Y chromosome, not sex per se. The last hypothesis I heard of regarding sex determination in hemp was that sex might be determined by the ratio of X to autosomes, not something coded on the Y.
This lacking knowledge on what exactly determines sex in cannabis makes the development of tests so hard. Having the raw DNA sequence or even the full codon including the respective proteins won't help either. What we need is not genes or DNA, we need functions, pathways, control mechanisms, that sorta things. In the end it could be different sets/activities/expression levels of enzymes (has been found but not very accurate), hormones concentrations (has been found for example for auxins but I don't remember if monoecious varieties have been tested as well), or something entirely new or unthought of.
Such tests on the other hand will tell the phenotype. Comparing it with the genotype (XX v.s. XY) reveals if it's a 'pure' sex or a hermaphrodite.
Whether or not this is possible also in very young plants before their sex is determined, I do not know, but Montana Biotech offers such a test (allegedly). If it's going to be possible for stress induced 'hermies'... only time will tell.
If it were my research, I wouldn't start with DNA but functional receptor/pathway-based assays. One problem here is that for many stresses we still haven't found how plants perceive them. We know which stressed do what and via which pathway but too often, the initial receptor is lacking.
If it's receptor based, it's likely going to be on a continuous scale and not black and white (i.e. gene present or not). The progressive loss of hermaphrodites over several generations during selective breeding instead of complete disappearance within 1-2 generations and also the possibility to reduce 'hermies' in likely any population is highly indicative for a QTL. We still don't really understand quantitative traits (such as size or skin colour); still, mostly based on luck, there are a few tests for such traits. But they are a PITA to establish and can't, for the time being, be built upon a known DNA sequence. On the other hand, an understood QTL would allow a test result indicating the % likelihood of phenotypical hermaphroditism.
May such lab test have a material cost of roughly $5 per protein/gene. Dunno why but nearly all I calculated a few years back turned out at that price. This goes only for materials and established tests, ergo 100% commercially available chemicals and reagents. They neglect time and equipment but include running costs such as buffers. Yes, for $5 even I would profit from such tests... But reality looks different and you got to pay quickly $50 and you may need more than one gene/protein. For someone who makes money with it, this is still acceptable but as a hobby gardener not so much.
I'd rather go with a quick&dirty test. Something like this: Take a cutting, put it in 5% glucose solution, wait 3 days and if it doesn't grow more than the control, then...