old seeds and 'blind' seedlings - any correlation?

[Ruth_10]

it would have to be an abberation of the same gene, or a similar gene that causes a blind seedling

It could be several genes are necessary for the process, start to finish, of divesting the seed coat, and loss of functionality of one or more would lead to varying degrees of blindness. It could be signaling factors that act up- or downstream from gene induction itself, as well.

Not sure if the seed coat gets harder with seed age - I always assumed that it is the embryo that gets weaker (as it slowly consumes nutrients that are stored in the seed over time), and that's why it gets harder for the seedling to shake off the coat.

Loss of vitality of the embryo sounds right to me. A seed that is kept frozen for many years (metabolic processes slowed to almost nothing) is both old and has a dry seed coat, yet is able to germinate and shake off its seed coat. A seed that is kept at room temperature (metabolic processes continuing at a good pace) for many years is old and its seed coat is at ambient moisture; success here will be variable.

Dice, would be interested in the reference on triploids, or even a rough time frame for when it was published.

[carolyn137]

Dice, would be interested in the reference on triploids, or even a rough time frame for when it was published

****

Ruth, I'm really pressed for time right now to look in my faves for the excellent article I have about polyploidy in tomatoes, if it's still active, but if you go to Google and enter tomato polyploidy you might make a hit.

There are some varieties that are just naturally triploid as I recall. And stable.

[dice]

Dice, would be interested in the reference on triploids,

This may have been it. I seem to recall a little more detail
in the chromosomal illustrations, but these are probably
close enough, and this paper covers a lot of the same
ground:

http://www.genetics.org/cgi/reprint/13/1/1.pdf

A paragraph from
http://www.cartage.org.lb/en/themes/...andSomatic.htm

sums up the sterility problem (aneuploidy):

Triploids. During the meiosis of triploids, trivalents are
formed. In the following anaphaseI, the chromosomes are
distributed onto both daughter cells. Only in rare cases, one
gets exactly the double amount (2n) of the simple set (1n).
Generally, both of them are equipped with incomplete sets
(aneuploidy, see next section). This results nearly always in an
imbalance of the chromosome composition leading to lethality.

[clkingtx]

Ok, I am kind of learning as I go. I have started Tiny Tim, Ace 55, big red cherry, and a unknown type from saved grape tomato seeds. It appears that every single one of them is blind... I can't see a growing tip on any of my plants...I had noticed earlier on that one variety looked really odd, but seemed to grow out of it, kind of. Can you all share your experiences with blind seedlings, and why you think it happened in your case, if you can, and the outcome of the plant. 2 of my varieties were about 5-7 years old, 1 was 2 years old, and the cherry tomatoes could have been new, or could have been a couple of years old, not sure(I mixed the new seeds in with the old, by mistake). I reused the potting mix from my flower planter boxes for all my starts. I will post pics here when I get a chance. How likely is this to happen?

Thanks,
Carrie

[efisakov]

Carrie, I am not a specialist on that, I just had one cotyledon leaf plant once. It grew bigger and bigger without developing any true leaves, just that one cotyledon leaf. I had to kill it. It was 14 inches tall with thick healthy looking stem. It was green zebra.

[clkingtx]

Thanks for replying, efisakov, I'm sorry that you had to kill your green zebra plant. I hope mine won't be that way.
I went and looked at some commercial grown tomato plants, and I am not sure that mine are all blind. They are very leggy, and pretty sparse in growth, but maybe not blind. It has been so long since I grew plants, I don't remember what stuff is supposed to look like. I need to do some more research and find more pictures of young tomato plants. Each of my plants have several true leaves, so even if they are blind now, maybe they will grow out of it? That's what I am hoping for. This is a fascinating subject though....

[Gavriil]

Have no Idea but I've been playing growing tomato's and peppers indoors without all the fancy lights and stuff, first sets planted seem to grow natural but died from over watering second third and fourth plantings are getting more blind seedlings, thinner growth and pods not coming off may have something to do with the potting soil/dirt I reuse mine and add some dirt mixture as I go. Like I said I just play to see the effects as they grow and occasionally get something to transplant in the garden.

[efisakov]

Originally Posted by Gavriil

Have no Idea but I've been playing growing tomato's and peppers indoors without all the fancy lights and stuff, first sets planted seem to grow natural but died from over watering second third and fourth plantings are getting more blind seedlings, thinner growth and pods not coming off may have something to do with the potting soil/dirt I reuse mine and add some dirt mixture as I go. Like I said I just play to see the effects as they grow and occasionally get something to transplant in the garden.

Hello, Gavriil,
wet the pods with a drip of water few times a day and they will come off.
To keep my seedlings healthy, I use 1 part Hydrogen Peroxide (3% sold at any store) with 3 parts water. I water my seedlings with that once a week. If they dry out, I will use just plain water. It keeps fungus and gnats away. And yes tomatoes do not like been overwatered.
wish you luck

[Tormato]

Saliva, after a drop of water, keeps the pod from drying out.

Hmm... I think it's time to check on the Ace 55 (1965) seed. It's been out of the deep freeze for about 5 years, so I don't know if any will germinate.

Gary

[dice]

On the occasional blind seedling that I get, after the cotyledons,
it develops a (usually oddly shaped) true leaf, and that is it. There
is no growing tip with a stem lengthening under it. I have no idea
what causes it (I assume some genetic defect).

I have also had seedlings that initially had a growing tip above
the cotyledons, but then it was bitten off by a pill bug (also
called sow bug, or roly poly). Examining it with a magnifying
glass, I could see scar tissue. Pill bugs normally eat decaying
organic matter, but if they come indoors with compost or
something, they will chew on tender new growth at the tips
of seedlings as an alternative food source.

(I found a few in the pots after seedlings that seemed to be
growing just fine suddenly stopped.)

[nctomatoman]

So after growing thousands (4000 per year of up to 100 varieties of all different ages, some going back to 15 years or more), the incidence of blind seedlings as well as stuck seed coats does correlate with really old seeds - this year I went back to lots of varieties in the 12-16 year old stage, and there are significant more issues with them. I planted sufficient seed to get what I needed for grow outs, but it is easily observed as a phenomenon.

[dustdevil]

Besides old seed with dried seed coats that should be presoaked...

I would surmise that a genetic defect in the seed coat would lead to the hathead trait being passed down the line too. This could be tracked in the growout of future generations to see if it applies.

Some of the hatheads I've removed never had any leaves form inside the shell.

[tomatoguy]

I have been starting from seed for about 15 years, now. I haven't noticed any correlation.

mater

[loeb]

Originally Posted by dice

On the occasional blind seedling that I get, after the cotyledons,
it develops a (usually oddly shaped) true leaf, and that is it. There
is no growing tip with a stem lengthening under it. I have no idea
what causes it (I assume some genetic defect).

I have this case this year and I would really prefer the plant to grow normally as it is supposed to be one of the parents to the cross... If any normal growth will show is that plant still valuable to breed with?

[Tormato]

Originally Posted by loeb

I have this case this year and I would really prefer the plant to grow normally as it is supposed to be one of the parents to the cross... If any normal growth will show is that plant still valuable to breed with?

loeb,



I'm glad you revived this thread, as I was just about to start a new one on the subject. I too have a case of blind seedlings this year (from 10 year old seed).


But, what I have on one plant, and have never seen before, is leaf growth BELOW where the cots were supposed to be. This seed took 6+ weeks to germinate, so the plant is still too small to tell if this growth will turn into a header.