I'm working with some orchid species, and i encounter a specific issue. Some of those species deposits upon their seed coat a wax layer. This layer makes seeds behave in a very hydrophobic way. You cannot dispense them in a pour water.

That behavior has many impacts. One of the most significant is that it does not let water come in touch with the actual seed and then with embryo to make it sprout.

So i tried many ways to remove that layer but nothing actually seemed to work out.

I treated seeds with the following chemicals:

a) 1% NaOCl with some dish soap water solution for 10min. After throwing seeds into this solution you could see that they can be evenly dispensed in it and come in touch with the solution. But if you wash them up with pure water for example 3 times they are getting back their hydrophobic behavior.

b) 1% H2SO4 water solution for 10min. I thought that with this treatment waxes will be removed from the seeds but nothing like that happened. Maybe they had been better dispensed in the pure water comparing to the previous treatment but nothing significantly changed.

c) 93% ethanol solution for 1, 2, 3, ... 30min. results here were also very disappointed. While the seeds are immersed into ethanol, they were very well dispensed into the liquid without any hydrophobic behavior. After three washes with pure water, hydrophobic properties came back.

Treatment time seems not to play any significant role on the results.

My conclusion is that there is no destruction of the waxes with the above chemicals. The only thing that happened probably, is the creation of a Micelle around the seed, which make it for a while (the time that it was in the solutions with soap and ethanol) non hydrophobic.

Finally my question is, if there is any way to destruct chemically, to some grade the waxes. So even when you put the seeds in a pour water not be so much hydrophobic.

Thank you.

  • $\begingroup$ Solvents like hexane/pentane/heptane/toluene are excellent for getting rid of wax/grease in a chemical sense (like dissolves like), however I'd be cautious about using them with biological material like seed samples as theres the potential for the solvents to penetrate and kill the while thing. $\endgroup$ – NotEvans. Feb 7 '16 at 14:36
  • $\begingroup$ Yes, i also thought of such organic solvents but i believe that they are gonna harm the living cells. Or maybe in a very small concentration do not harm them. $\endgroup$ – F.N Feb 7 '16 at 14:55
  • $\begingroup$ You might be better posting in Biology.SE, I'm sure there will be a common procedure for doing this that a plant biologist would know, rather than us chemists speculating about what chemicals would remove it without killing/dissolving the rest of the seed :) $\endgroup$ – NotEvans. Feb 7 '16 at 15:04
  • $\begingroup$ Maybe you are right :). I will post it there too. $\endgroup$ – F.N Feb 7 '16 at 15:14
  • $\begingroup$ I'd wonder if you're going in the wrong direction. A drop of dish washer soap shouldn't cause any harm to the seeds and would likely be enough to disperse the seeds in the water. $\endgroup$ – MaxW Feb 7 '16 at 20:00

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