Re: Re: HYB: Induced polyploidy in irises


Robert, I grew up in the high desert country in the intermountain west.  The mention of late frosts, for example, certainly applied to us.  The weather in SW Idaho is erratic, being in a boundary area among contrasting air masses of Pacific, Polar/Arctic, and Continental origin and even the monsoonal system which comes into Arizona and New Mexico occasional affects the area.  Changes such as Chinook conditions, and the reverse from Arctic spill-over from Montana all can occur abruptly.  I have seen sudden drops to 8 degrees in October, drops to 20 degrees during TB season in late May, and even light frosts in the middle of June.
 
I have seen wedge segments of "sporting" involving color in tall beardeds numerous times. I have also seen this in commercial apple production.  I have never observed anything that suggested unexpected polyploidy in weeds, native plants or iris, however.  Usually, amphidiploid or any other kind of tetraploid plants are enough different in character from the norm with larger stems, heavier textured tissues, thicker leaves and petals and so on that the change would be at least marginally noticeable if not conspicuous.  I was highly observant of plants and not only grew many thousands of irises from seed but roamed the desert, the exotic riverbanks, the areas of perched water tables emerging from hillsides and so on.  I also spent a lot of time in among the Miocene remnants growing in the "desert canyon" flora in microclimates found along small stream flow originating from high elevations and flowing down into the hot, long-season semi-arid steppe and near-desert conditions below them. If there were common incomplete mitoses resulting in tetraploidy occuring from abrupt, out-of-season frosts I believe I would have seen such.  The phenomenon must be exceedingly rare.
 
More likely are accidentally induced polyploids from near fatal exposures to those herbicides able to induce such.  I have not been around agricultural areas much since these have been in use, and I would find such mutations in "weed" populations rather alarming.
 
I, too, am an optimist considering the possibilities.  The controlled use in obtaining fertile hybrids across ordinarily sterile barriers in our irises is something for which I have an appetite.  I heed the caveat, however.  I realize the Treflan/Surflan etc. types are exceedingly toxic.  If they can affect plant tissues in this manner in minute concentrations, I rather expect they would play havoc with human tissues as well.  One of the state employees at a local research center and I have spent some time talking about what might be possible here.  His work is in tomatoes, but my interest in use with irises is not foreign to him at all.
 
Neil Mogensen 

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