A 'prematurely greened' embryo in culture

Now 15 days into jar-culture.

The other 18 embryos which were cultured in the same jar as this one in the picture now have at least one true leaf, some have two true leaves. They are all behaving as any other normally-germinated rose seedlings would, in their seed raising mix.

However this ‘prematurely greened’ embryo is still clinging to dear life in the jar, and is having a very hard time deciding what to do! Its growth is still incredibly retarded.

Can anyone here explain to me how this embryo showed green cotyledons at the time it was removed from its inner seed coat?

In a normal embryo, greening of the pearly white cotyledons takes a few days of light exposure.

Could this green be some type of non-chlorophyl pigment causing defective energy production?

Below are pictures of three trays, each with 6 seedlings that were embryo-cultured in the same jar as the ‘abnormal green embryo’ that is causing me trouble.

I had 10 in the jar containing the ‘abnormal green embryo’ originally, but later added more to the jar, so in fact some of these are even younger than this weird green embryo!




Can anyone here explain to me how this embryo showed green cotyledons at the time it was removed from its inner seed coat?

You may expect to encounter some spontaneously germinating embryos as you process your seeds.

Don, I am asking how did the embryo develop green cotyledons inside an intact inner seed coat and intact achene shell. Can light photons penetrate these barriers?

Can light photons penetrate these barriers?

Sure. In fact, if the sutures are sealed and and the pericarps are intact then the presence of chlorophyll in the embryo is prima facie evidence that light got to it.

Keep in mind that the creation of chlorophyl is a different thing than using chlorophyll to conduct photosynthesis.

Chlorophyll is the end product of a great many biochemical steps. One of the very last steps requires light, but it only takes one photon to produce one molecule of chlorophyll, so a little light goes a long way.

I probably should have mentioned this in the manual. Since it’s a digital download I think I’ll go ahead and amend it. Good question, George.

Hmmm… nature is so incredible!

Not to mention that the hips containing these achenes were fresh and hard in their consistency, and there were no adventitious seeds to catch the bright light directly (they were the usual iceberg OP hips, smallish and with few achenes inside).

I really am astonished that light photons are able to penetrate and strike an embryo buried so deep inside an intact hip…so many layers!!

‘adventitious seed’ written above, was meant to read ‘exogenous seed’

Well, just to complete my little ‘chat’ about the prematurely greened embryo shown above… it died yesterday.

Maybe it had unsustainable high ploidy?

Have a nice day all.