Re: gibberellin seed treatment
writserv@mi.net
Fri, 16 Feb 1996 18:41:17 -0400
> Demetrios asked about measuring out small amounts of gibberellin
>for use in seed treatments. May I refer him to the method described by
>Norman Deno. Deno uses moist paper towels for germination studies [of a
>vast range of plants], and 1000 ppm GA3 was one of his treatments. He
>describes using a folded 2-inch square of towel, "which holds 6 drops of
>water". He found that 1 cubic millimeter of powder, described as "the
>amount held on the tip of a round toothpick", dissolved in this much
>water gave the desired 1000 ppm. This sounds exceptionally crude, but it
>works [and Deno, by the way, is a retired chemistry prof]. I don't like
>the towelling method for tiny seeds, so I measure 12 drops from an
>eyedropper into a porcelein spotting dish [a standard micro lab
>accessory, easily obtained from biological supply houses]. I add two
>"toothpick units", add seeds and cover the cell with a microscope
>coverglass. It's necessary to observe the seeds daily with a lens. When
>the seeds swell, or a few start to germinate, I pipette the lot [with an
>eyedropper] onto appropriate seed medium.
>
> The only problem with stock solutions is that gibberellins are
>not very stable in solution. It appears that the target range of
>effective concentrations is not narrow, so an approximate technique like
>this can work.
>
> It's noteworthy that gibberellins stimulate seeds of plants from
>a wide range of ecological situations. In addition to CPs, a variety of
>forest herbs, plants from alpine screes, and even cacti erespond. Deno
>suggests that the giberellins are indicators of fungal metabolism, of
>consequence to many higher plants
>
>Loren Russell
Loren:
I toss my seeds on a bunch of wet sphagnum and pick out the ones that are
trying.
I'll have to work on this. (;-{)}
Rand