Abstract: "Abstract: Rose breeders need reliable and efficient germination protocols to exploit all viable embryos in their breeding programs. In this
study, different treatment combinations were assessed to overcome the mechanical resistance of the pericarp and enhance germination
of rose seeds obtained from hybridization among hybrids roses. In the 3 treatments, 30 days of a warm temperature followed by 60 days
of cold stratification and 30% sulphuric acid treatment for 10 min proved more effective in getting higher seed germination (18.54%)
and seed vigour index (261.18) of the progenies. This led to lower germination (18.20 days) and imbibition (23.64) periods with respect
to the other 3 treatments including the control. This treatment also helped increase the total length of progeny (14.1 cm) and number
of leaves per progeny (6.44), whereas the response of other growth parameters of progeny was variable to this treatment. Correlation
(r) between pericarp thickness and seed germination percentage, germination period, and imbibition period proved highly significant
(r = 0.347, P < 0.05)."
See full paper at:
Any thoughts as to whether the sulfuric acid soak could be done prior to stratification?
I could actually test this pretty easily, I think. I have 93% sulfuric acid on hand. Gotta remember not to add acid to water, though, when I dilute to 30%.
Joe, how would you dilute it if I may ask.
If you have 93 % sulfuric it is close enough to add 1 part of that to two parts of water. There are some issues with the actual density when it comes to measuring the sulfuric compared to water. Most people do do the sulfuric acid scarification first. it is very effective with hard-seeded legumes when treating large masses of material. But for a few seeds of something like Kentucky coffee tree usually it is easier to just file a notch through the seed coat to get the same effect. With roses you are probably having quite a few achenes, but they may be precious enough that you don’t really want to risk the damage that too much sulfuric will do. There are a number of papers reporting that it did not work effectively- see my review for details. My own prejudice is that nitrate works more reliably and safer. Have yet to find a CV for which the nitrate treated was poorer than the control and for most they are a whole lot better.
I’m curious if these treatments, either the sulfuric acid or the nitrate, might help germinate Prairie Peace seed, which is supposedly viable but doesn’t germinate due to a hard seed coat. If you’re interested, Larry, in running a test on OP Prairie Peace seed I’ll send you some this fall. I’d love to hear the results even if you throw them away. I could test a sulfuric acid presoak while you test with the nitrate.
If you’ve got the seed, I’ve got the time. Also the sulfuric acid. I couldn’t guess why you’d have it at a nursery. Muriatic- HCl- is all over the place but sulfuric? Mighty powerful oxidant.
Even with nitrate, some seeds are pretty much recalcitrant, but for species it has done some wonders. Take a look in the last newsletter for a couple, for instance glutinosa. Also the Knock Outs.
I’ve use sulfuric on a lot of species of hard-seeded legumes and prefer notching if I only need a dozen or so seeds at a time.
BTW, I have another massive test series going to compare nitrate on other CV not previously tested. And to compare it to karrikins, which stimulate germination of plants in places dominated by fire. So far that’s pretty disappointing, but I will have a ton of data. Roughly 300 packets of seed, 2/3 in these tests, monthly counts. No plans for next year at all except my own crosses. so a few for comparison to sulfuric would be fine.
Larry have you compared nitrate to enzymes?
No, I have assorted enzymes, but they’re not readily available to most folks so I decided to stick with simpler things. I know that Garotta ( bacterial mix for composting) really worked well. And I know that you have tried a few things. I figure that the seed probably has what it needs, just perhaps not enough. The idea with nitrate is that it is a specific inducer of what the seed needs to release to open the achene. Generally they just fall open at the suture. Sort of like how GA will induce malting effects in barley I think that the NO produced from NO3 is a signal. What is next in the pathway I have no idea.
I tried to pick readily available enzymes. Enzymes are involved in nature - seed germination when birds and small animals eat the hips.
Henry and Larry, would it be possible to collect chicken poo and soak the seeds in it at some dilution rate. The other idea was to get a chook to eat some seeds in a controlled environment and then harvest the seeds from the poo. Only ideas at present.
I would wonder if the digestive acids\enzymes would have more of an effect that the actual poo.
See this thread. One of our members (Enrique) used his pet dove to process his seeds a few years ago.
Thanks for that Mark, good reading material. On reading the part about pineapple, it reminded me that a lot of chefs are using ‘kiwi fruit’ to tenderize squid/octopus and other things, might have a go at it plus some of the others that have been mentioned.
Those same enzymes in kiwi and pineapple are what cause them to dissolve gelatin. Decades ago, my best friend’s mother made her “signature” fruit gelatin for a church function, though she mistakenly included kiwi. By the time she arrived at the event with her dish, it had completely dissolved into goup from the kiwi. Pineapple has to be cooked prior to including in gelatin for the same reason.
In addition to a comparison of a drain cleaner enzyme product versus a nitrate, a drain cleaner first, then a nitrate second procedure may be interesting.