What's new
TerraForums Venus Flytrap, Nepenthes, Drosera and more talk

Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Nepenthes attenboroughii seeds germinated!

  • #21
Flasker I think no one has mentioned the most important difference--osmolarity. If you think about the water in planting medium, it is relatively pure, maybe maxing out at 200 ppm tds. In contrast, the tc medium might have 30 g sugar, 6 g agar, and lets say 1.5 g salts. That water contains 37,500 ppm tds. So for the purposes of osmosis, these environments are very different. My own opinion is that this is the most likely explanation for differential results between soil and tc.

Mikewilder,
You may be right!!! Osmolarity is too high so seeds get less water -> germinate longer. I use 10 g sugar, 4 g agar and 1 g salts but it's still too high than ~ 0 ppm tds (distilled water). Seeds germinate well but take longer. It happened to me 3 times. I will try next time in vitro with coconut coir and distilled water only or with very diluted salts. However, some other seeds germinate very fast in normal media so it may depend on what kind of seeds. Anyway, Thanks !!! You're ingenious!!! Play with TC Mike ?
 
  • #22
It's important to understand that I'm not claiming that osmolarity is the only relevant variable. I simply claimed that it was a relevant variable no one mentioned. It is my opinion that it is very relevant in explaining differential germination in pots vs test tubes, where the sower claims all other things (except humidity) are being held the same. It is a demonstrated fact that osmolarity differences are critical in getting many haploid cells to grow in vitro, for example. In general my experience is that seeds take longer in test tubes than in pots, though like just about any phenomenon in biology, exceptions can be found.

It's not obvious to me how seed freshness or general viability explains differential results in pots versus in the test tube--please clarify David. Like 'God's will', "other factors not being considered" are always a possible explanation for any phenomenon in the universe. One of the nice features of my explanation is that it is testable.

"I'd suggest that the solute concentration can't be significantly higher than some of the standard, saturated peat-sand composts that I use." This is an empirical claim that is easily tested with a tds meter. But I'm wagering you are wrong. 2% sucrose is 20,000 ppm, 1/3 strength MS or LS will be about 1500 ppm, 4 g agar is 4,000 ppm. Pour some water through your pots and see if it measures 25,500 ppm tds. If it does I'll mail you a big Heliamphora or do it as a Nasc auction, your choice. Let's find out--

Osmolarity certainly plays some role; but what of its supposed deleterious effects? I have experienced in vitro and conventional germination within ten days of some Nepenthes, Drosera, and Darlingtonia; yet have also waited for months for some of those same plants -- which points more towards seed freshness; its general viability; or other factors not being considered. Also, considering that I average some twenty vessels per liter of prepared, diluted media (generally 1:5 to 1:3 concentrations and sucrose at about 2 percent), I'd suggest that the solute concentration can't be significantly higher than some of the standard, saturated peat-sand composts that I use.

In addition, similar "either / or" results occurred with some 2011 photo-autotrophic cultures, where solute concentrations were kept far lower (sugars were not even included in the media); and where "normal" rates of gas exchange were obtained through vented lids . . .
 
  • #23
It's not obvious to me how seed freshness or general viability explains differential results in pots versus in the test tube--please clarify David. Like 'God's will', "other factors not being considered" are always a possible explanation for any phenomenon in the universe. One of the nice features of my explanation is that it is testable.

"I'd suggest that the solute concentration can't be significantly higher than some of the standard, saturated peat-sand composts that I use." This is an empirical claim that is easily tested with a tds meter. But I'm wagering you are wrong. 2% sucrose is 20,000 ppm, 1/3 strength MS or LS will be about 1500 ppm, 4 g agar is 4,000 ppm. Pour some water through your pots and see if it measures 25,500 ppm tds. If it does I'll mail you a big Heliamphora or do it as a Nasc auction, your choice. Let's find out--

When I had mentioned "general viability," the freshness of the seed -- especially Nepenthes -- plays an obvious and significant role in the rate and speed of germination in either form of media (whether they'll even sprout in compost or TC media at all); the genera being notorious for even having a low viability in the wild. The low-land species can have seed viability measured only in terms of weeks; while I have had highland seeds sprout after two years under refrigeration. Alternatively, I have had seed that I had personally collected that germinated within a couple of weeks in vitro, yet took eight to ten weeks in compost. I have found that the age of the seed to be a primary factor with either method. "Other factors" could include varying photoperiods; distance from lights; color temperature of said lights; temperature of the grow rooms; methods of seed sterilization; whether the TC vials were vented; whether the media was properly prepared, etc.

Generally, seventy-five percent or more of my Nepenthes and Heliamphora seed germination occurred far more rapidly in vitro -- measured in terms of weeks; but there have been those occasional exceptions. The photo-autotrphic method has even been more successful.

In terms of solute concentrations, I was thinking more of the peat "teas" that I had prepared in the past, not so much a three inch pot of peat and sand; and the TDS of that stuff (or, perhaps more properly, TSS), was quite high . . .
 
Last edited:
  • #24
:) The question was why DON and Flasker observed differential germination in pots and tubes. You yourself replied that:

I have had both experiences -- where the seed germinated in vitro weeks before those in compost; and quite the opposite, even with both kept in the same environment, in terms of temperature and light.

So you seem to agree that differential germination in the "genera" [sic] Nepenthes is typical or at least common, even where the environment is the "same" in terms of "temperature and light". But agreeing that it happens doesn't explain it.

You proposed that since differential germination happens, but in unpredictable ways (sometimes tubes first, other times pots first), it's probably to be explained by seed freshness, viability, or anything other than osmolarity.

I asked how freshness or viability could explain differential germination in pots and tubes. After all, whatever the age is, that's the age of all the seeds. If it's so important, you'd expect the same results in pots and tubes, because the age of the seeds is the same. Whether general viability is randomly or uniformly distributed in a seed packet, you wouldn't expect differential germination in pots and tubes, at least with reasonably large samples.

So I'm sticking with what I said before--it's not obvious how these factors can explain the observed differential germination that we're trying to explain. Nobody was wondering whether age or viability determines whether a seed will sprout. That just goes without saying, doesn't it?
 
  • #25
something to keep in mind, a "TDS meter" does not measure Total Dissolved Solids, it measures conductance and translates an approximate TDS based on calibration with a salt solution. If a solution has a high concentration of compounds with weak dissociation or ionic strength (low conductivity) it will read a much lower approximate TDS, a false result. These solutions will still have an osmotic pressure corresponding to their concentration.
 
  • #26
:) The question was why
I asked how freshness or viability could explain differential germination in pots and tubes. After all, whatever the age is, that's the age of all the seeds. If it's so important, you'd expect the same results in pots and tubes, because the age of the seeds is the same. Whether general viability is randomly or uniformly distributed in a seed packet, you wouldn't expect differential germination in pots and tubes, at least with reasonably large samples.

Seventy-five percent of the time, seed of known age in vitro preceded those in composts, in terms of weeks; and I wouldn't expect the "same" results in both environments. It is generally weighted toward the TC media, three to one -- especially those kept in obscurity for ten days after sowing -- by about two weeks, in my experience.

I would also attribute a good portion of human error to media preparation (as a possible explanation for delays in germination versus compost), since it is as rampant in industry as among hobbyists -- everything from the improper choice of salts (there are innumerable Muroshige Skoog mixes now available, with and without vitamins, etc.); their concentration (since MS is high in ammonium compounds - anathema to Nepenthes); the type of plant growth regulator used; improper calibration of pH meters; improper pH; improper carbon source for the genus; not taking into account the post-autoclave drop of pH, which can be significant. Was a PGR even used during germination, since many choose "plain" media for that purpose?

Then there is the method of sterilization of the all-important seed. Were they bleached all-to-hell before placed into TC media (as an aside, I generally don't treat seed going into conventional compost)? Did the 70% ethanol dip affect them? Was PPM used for sterilization; and if so, what was the concentration and duration; and the concentration of the MS salts used in the solution? There's also some talk that PPM delays or inhibits TC germination by some growers; though that jury seems out for the time being . . .
 
  • #27
Ummm... My attenboroughiii seeds are germinating! I'm up to 13 seedlings. YAY!!! :-))

Admittedly, I may have made a mistake in putting together the media. I was in a rush to go on vacation but wanted to plate the seeds before I left. The seeds look like they are sitting on very firm jello so I must have miscalculated the amount of agar. If I mismeasured the agar, who knows what I did with the BAP and PPM. I just might make a batch of fresh media and replate. I have new seeds coming anyway.

I'm still learning this TC stuff and having fun with it. Thanks BigBella for all the advice you've given me so far.
 
  • #28
Congratulations!

Those I have in media are still a few weeks behind you. I hope to see something by Christmas . . .
 
  • #29
@David, what temps are your seeds experiencing?
 
  • #30
@David, what temps are your seeds experiencing?

I am giving them intermediate to highland Tbs -- days in the seventies; nights in the low sixties or upper fifties. That has generally worked for me in the past . . .
 
  • #31
Im doing the same temp range for them and still no germination, perhaps attenboroughii germinates much quicker in lowland temperatures.
 
  • #32
My first seed germinated this afternoon. It seemed to happen pretty quickly because when i checked in the morning there was nothing. I actually got inermis germination this morning too.
 
  • #33
Congrats, Heli! You should see more pop up very soon. I'm up to 26 sprouts since I first observed germination on 12/1.

How are everyone else's seeds doing?
 
  • #34
Congratulations guys. Glad to hear that the species has been introduced well into public hands. I wish i had some too. But well...in time...hopefully.
 
  • #35
Mine haven't done anything yet. They should start germinating next week.
 
  • #36
Nothing from mine, but they've only been in the media for 7 days now. It's interesting how squat they look compared to the regular 'stringy' Nepenthes seed.
 
  • #37
Here is my lame excuse of a photo :lol:
Its hard to see but look at the center of the photo and you can see it
8C4CC908-8AA7-400A-BE50-5E445D921970-718-00000039B92C1824.jpg
 
  • #38
It's interesting how squat they look compared to the regular 'stringy' Nepenthes seed.

N. attenboroughii seeds in TC:
image_zpsa6f5a98d.jpg


N. lowii Mt. Trus Madi seeds in TC:
image_zps97068375.jpg


Very different structure.
 
  • #39
heli i have the best vision that is possibe to get and i cant see it
oh you ment there well now i can see it
 
  • #40
8C4CC908-8AA7-400A-BE50-5E445D921970-718-00000039B92C1824-1.jpg
 
Back
Top