I think that Don is right that suberinase could be beneficial, though suberin is more lie a paint than a glue. It covers surfaces of roots, or injuries. A gule is more likely to be pectin. You can get pectinase for clarifying fermented beverages at a place that specializes in wine and beer production. Pectin is one of the main causes of haze in wine. The very best thing would probably be macerozyme, which may be the same thing as driselase and is used to digest leaves to isolate single plant cells. Henry’s evidence is that bromelain, a proteinase works ok somehow. I doubt there is much lignin in the glue holding the achene pieces together. In the walls themselves, yes, but probably not in the suture.
The very best results for germination of dogrose for rootstock production was a material sold in UK as Garotta, a compost activator. In France that name would have other connotations, perhaps intended by the designers of the stuff. Jadae is right that the local health food store sells lots of bizarros, some of which actually have something useful in them.
An alternative might be to collect tomatoes that are suffering from soft rot. The pectinases in the fungi growing on those might work. Rotten oranges or apples might work too. Their seeds tolerate the rot well enough.
Actually Don’s suture popper works really quickly without damaging the seed inside. I used it on some really tough Knock Out achenes. The embryo inside an intact testa pops right out. Then you just have to leach or metabolize the stuff in the testa by usual strategies if you don’t want to skin it and get rapid germination.
I was doing some reading on cellulses and found that these are often produced by fermenting micro-organisms in ruminants. Then your comment on tomatoes made me think of something else… I’m a chronic tomato seed collector too and the best way to collect tomato seeds for germination from your favourite store-bought tomatoes is to take the tomato pulp with the seeds in them and then ferment them in a jar (see link for more information). After a while you screen them out and sow them. The fermentation process prepares the seeds for germination and you get excellent germination rate. I wonder if fermenting rose seeds, or fermenting rose seeds with tomato pulp, would also do the trick and the anaerobic fermenting bacteria might produce a range of enzymes that could weaken the integrity of the seed as a whole… not only the suture???
Actually Don’s suture popper works really quickly without damaging the seed inside.
You made one? Way to go, Larry! Give us a picture, eh?
Dr. Kuska’s results with bromelain have me mystified. It’s a broad-specificity protease with obvious activity at sulfur bonds rather than glycosyl bonds so one wonders what’s getting chewed up in an achene that would tenderize sutures. One possibility is that the action is indirect. Maybe it digests enzymes needed to maintain the pericarps.
I’ve come to think that achenes ripen in the same way that fruit does and that the weakening of sutures is largely an intrinsic phenomenon related to that. Perhaps the necessary enzymes are made by the pericarps or even the testae. The testae are clearly very active in living seeds. My feeling is that they perform a lot of functions, all fueled by storage compounds in the embryo.
I haven’t seen any studies on the composition of the outer coat of rose achenes. I have seen studies on the composition of strawberry achenes, and strawberries are also members of the rose family (Rosaceae). The outer coat of strawberry achenes consists almost entirely of lignin with a very small amount of pectin and protein. No cellulose was detected. That means that enzymes that attack cellulose would be expected to have no effect on strawberry achenes.
Fresh rose achenes have the hard waxy look of something made of lignin. They don’t look like something made of cellulose or protein. Based on a recommendation that septic tank treatments increase rose achene germination, I tried soaking some rose achenes in an undiluted septic tank treatment that contained enzymes that break down paper (cellulose) and other organic materials. I examined them under magnification before soaking, after one week of soaking, and after four weeks of soaking, and saw no difference in the exterior of the achenes. I then planted the achenes. There was no difference in germination between treated and untreated achenes. Don’t believe everything you read on the Internet about stimulating rose achene germination.
I think that it would be well worth trying a ligninase (enzyme that degrades lignin) on rose achenes, but I haven’t found a commercial source for it.
Interestingly, the classic sources of ligninases are the white rot fungi like Phanerochaete chrysosporium. These fungi are typically found on rotting wood, and may be the same white fungi that some of us have seen on rose achenes that seems to stimulate their germination.
The key to the failure to work “may” be the use of “undiluted” septic tank treatment. Possibly the septic tank treatment needed water to activate. Did it work on a piece of paper?
I tend to agree with Jim; most of these enzyme treatments are not worth the effort. I suspect most of these treatments have no effect, and in fact I am sure one of our members once reported a significant decline in germination of seed treated with enzyme versus a control group of the same seeds.
Personally, I have no trouble getting loads of seedlings from a wide variety of seed parents, with nothing more than standard cold stratification. I think that alternative treatments should be pursued only when you have seeds from a difficult cross that you are desperate to get to germinate; seed that has shown to be unwilling to sprout under normal conditions.
It occurs to me that we might actually have a ready-made enzyme source for softening pericarps (for promoting germination) and dissolving their sutures (for embryo culture).
I have noticed that pericarps from rotting hips tend to be more porous and less hard than from freshly harvested, ripe hips. This must be due to enzyme action. It may well be that the enzymes involved are produced by the flesh of the hip (as opposed to their being intrinsic to the pericarps, which is also likely).
The experiment would be to immerse seeds in the macerated flesh of hips that are just beginning to soften or have become pasty. Of course, this is exactly what happens when you toss hips in a corner for a while but since some hips have way more flesh than others it might be a way to promote germination for seeds from thin-skinned hips. Has anybody tried this?
I tried to use a microscope to examine fresh seeds, a seed after a 2 day soak in distilled water, a seed after a 2 day soak in bromelain solution, and a seed after a 2 day soak in Rid-X Drain Care solution. (The Rid-X used was the solid powder.)
Unfortunately, the microscope used has a very limited “depth of field” so one cannot have very much of the seed in focus at the same time.
My conclusion is that the pictures are inconclusive.
Off to get some tomata pulp and rose seeds togehter