Seed viability

[coldcoffee]

Does anyone know what the viability of Dionaea seeds is? I get different numbers: one source says 100 days before they lose viability significantly (and then rapidly thereafter), another source says 5 years. Anyone have a halflife with and without refrigeration? Gut instinct? Anything?

[Not a Number]

The only published data I've uncovered so far is in

Responses of Venus Fly Trap (Dionaea muscipula) to Factors Involved in Its Endemism
By Patricia R. Roberts and H. J. Oosting
Ecological Monographs, Vol. 28, No. 2 (Apr., 1958), pp. 193-218

They write:

Seed was set out to germinate at different time
intervals after collection, at the rate of 10 seeds per
test. Records were kept of the time of setting out
and the time of germination, i.e., when the radical
was first apparent. As the experiments progressed
it became clear that there was no apparent after ripening
effect of the plant on the seed, once the
capsule had opened.
After storage at 72F for up to 4 weeks, half of
each set of seeds was packaged in filter paper, layered
in sand, and stored in the refrigerator (36F) so
that comparison could be made between cold storage
and storage at normal temperatures.
Germination of unlayered seed averaged 87%
for the first 40 days and 56% for the next 60 days
(Table 5). After 100 days viability dropped to about
2% and after 140 days no germination occurred.

The time from setting out to the first germination
of seed in a set varied somewhat, but over the whole
time it averaged 16 days for unlayered seed and 11
days for layered. The time lag between the first
seed germinating in a set and the last, also fluctuated,
averaging 25 days for unlayered seed and 20 days
for lavered seed. As the unlayered seed aged, some
increase in the average time lapse was noticed between
setting out and germination, although this may
be more apparent than real. (Table 6). No seed germinated
when older than 126 days at the tine of
setting out, but some few seeds, which were set out
within 2 weeks of ripening, were up to 145 days in
age before they germinated. No unlayered seeds over
this age were viable and viability at this age was
extremely rare (Table 5).

After layering, the percentage of germination
remained high over the entire period of investigation.
After 9 months, seeds were still showing 86% germination,
equal to the average germination of up to 40
days for unlayered seed. The average over the whole
9 months period was 87%. Other differences have
already been mentioned.

The bolded text should tell you what you want to know. The article is available from JSTOR. Your public or university library should have a JSTOR account and be able to download a copy for you.

[coldcoffee]

Thanks, I'll have to download this when I am on campus again.

[meadowview]

Hi Cold Coffee:

We had two Governor's School students do a research project last year on the effects of nutrient fertilization and seed germination in VFT's. We're planning on submitting this paper for publication this fall.

Our students looked at germination rates of VFT stored in the refrigerator from 2004 to 2009. There was a linear drop in germination rate, with 2004 seed less than 2%.

Now, keep in mind, it probably is possible to store VFT seed indefinitely if the seed is dried to the correct moisture level and frozen. We simply air dried the seed and stored in paper envelope in refrigerator. Germination rates were still fairly good with one year old seed stored this way (42%). Fresh seed was 68% germination.

Sincerely,

Phil Sheridan, Ph.D.
Director
Meadowview Biological
Research Station

[Not a Number]

You may want to try a cross-reference check and see what other articles you can find that cite the Roberts and Oosting paper. Someone may have done follow up germination and viability studies.

[coldcoffee]

A linear drop huh? That's a bit unexpected...