MORE OBSERVATIONS /SUMMARY OF 12 MONTHS OF ROSE EMBRYO WORK:

I would like to share with all you that may be interested in embryo work, some of the most important observations I have noticed, as well as my own speculations, from my own embryo work with roses over the last 12 months.

I am definitely noticing that some embryos just fail to “activate / germinate” whatever I do with them. A lot of these are the ones that have their inner testa stuck against the embryo surface, and fail to “slip out” easily once part of the testa is cut open (so you have to scrape them out…lol). I am speculating now that these “stuck” embryos were not quite ready for germination at the point of collection of the hip, even thought the hips were well colored and “ripe”…These stuck embryos likely needed more time to ripen (perhaps embryo “ripeness” is signalled by the development of a gap between the inner testa coat and the embryo, with some lubricating substance forming between these surfaces which facilitates this slippage??).

Of course for comparison, from the same colored (ripe) hips we often get the embryos that EASILY slip out of their testa, as soon as they hit the glass of water (assuming an exit slit has been made in the testa coat). I can predict with some certainty now, that those that slipped out easily from their testa, (by whatever method of extraction) are very likely the germinators out of the colony…the performance of the other “non-slippers” is at best questionable, at least in my experience.

For example, looking back at Simon’s R.clinophylla x OP seeds whose embryos I cultured in the jar (see entries further up about this culture), I remember very well that only two or three of all the embryos actually slipped out with ease, the rest had to be teased out… I remember emailing Simon and telling him that I expected only 2 or so germinations the minute this happened…I am not surprised that these were the final germination results of that culture (3 germinations). I now speculate that the majority of my other R.clinophylla x OP embryos that were “stuck” in their testa coat, must have been late germinators, and unripe at the time of the culture (rather than “almost dead/dead” which is what I had originally assumed)…and so, as they remained in their suspended animation in the jar culture they stood NO CHANCE of ever germinating, as they were not ripe at the time their achene was removed for the culture…They very probably would have all germinated if sown directly in germinating medium…and probably would have been the late ones to germinate.

Simon’s great sowing success with the same batch of R.clinophylla x OP seed is what actually got me thinking about why all this discrepancy had occurred. If Simon had not got great success sowing the same achene I would have just passed it off as just “bad seed”, which was clearly NOT the case. I would never have thought beyond the obvious “they were dead for whatever reason” thinking…So it was fortuitous and very instructional…and in the end more knowledge has been gained out of all of these observations.

I am really starting to think/speculate that well colored ripened hips contain a percentage of unripe embryos (those that appear to be dry and stuck to their testa coat)…they are probably not simply “just very dry” even though they look that way at a first glance…they are likely “not ripe”" to germiante even though their hips were ripe. I speculate that most of these embryos all proabably die in the jar culture or plastic bag culture, or any other culture for that matter…not becasue they were “not viable” or necessarily “fungus infected” (sure, they become fungus magnets as soon as they die, and also if they are alive but with bits of testa stuck on their scraped surface which itself is dead tissue and attracts bad bugs…lol).

If there is some truth in this speculation, then the implication of course is that embryo culture risks losing the late-germinating (unripe) embryos of that colony…which if true, is really too bad. Of course, the risk of this embryo culture loss has to be weighed against the risk of losses by conventional sowing of the same achene.

I am now comparing some jar culture versus some direct planting of embryos derived from colored (ripe) hips, to see how one performs against the other, using embryos from the same hip/plants. There seems to be no great difference that would worry me any more, now that I have fine-tuned things a bit. I am personally doing away with the jar culture, and now direct planting embryos that are derived from hips which have colored well.

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The more I think over the last few years of dabbling in various embryos of fruits (other than from rose), I can definitley also say that in my experience, I have had the best percentage in embryo germinations in such fruits (olive, sour orange, lemon) from fruits that were picked right at the end of the season, compared to their early counterparts which had only just started to change color.

So, for any future embryo work I chose to do, I am definitely going to be using hips that are maximally ripened/colored, say just before wrinkling sets in. I am guessing such hips will contain the most/optimal number of “ripe” embryos.

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