Ping seed germination and germination inhibitors

From: Loyd Wix (Loyd.Wix@unilever.com)
Date: Wed Jul 30 1997 - 04:46:12 PDT


Date: 30 Jul 1997 12:46:12 +0100
From: Loyd Wix <Loyd.Wix@unilever.com>
To: cp@opus.hpl.hp.com
Message-Id: <aabcdefg2865$foo@default>
Subject: Ping seed germination and germination inhibitors


          Dear all,
          =

          following on from Marcels request recently I though I would =

          share some experience I have had this year on germinating =

          European Pinguicula seed without a stratification period.
          =

          Conventional Adrian Slack wisdom instructs you sow your =

          seeds then expose them to frost durring the winter to =

          stratify the seeds. Great! But what happens if you receive =

          seeds in the spring or summer with no frosty nights? Hold =

          onto the seed until Winter and perhaps loose viability - or =

          you could place the pots/trays into the deep freeze though I =

          have not found this to be successful. Well here follows a =

          tale of germinating Euro Pinguicula without Stratification : =

          =

                =

          I have recently made a break through in the germination of =

          P.alpina seed. I have been trying to germinate this species =

          since 1990 with no success. I have tried seeds from many =

          sources and localities including seeds freshly harvested by =

          friends. This had been most frustrating as I have germinated =

          many Euro - Pinguicula from seed and could not understand =

          why P.alpina should be so difficult.
          =

          This year I tried a different approach for a variety of =

          reasons. I was sent some seed by a pal in central Europe =

          which included 3 different locations/forms of P.alpina and =

          some P.vulgaris. It was too late in the year for any frost =

          to stratify the seed and I didn't want to put the seed into =

          my deep freezer. I remember reading an article by Miloslav =

          Studnicka on a method he uses to store Euro - Pinguicula =

          seed for prolonged periods of time. His method involves =

          soaking the seed in water to remove the abscisic acid (ABA) =

          and in the dark to avoid germination - such treated seed =

          would maintain good viability for several years. I decided =

          to use this method to remove the ABA so the seed would not =

          need to be stratified, and placed the seed in plastic =

          containers with approx 200ml of cooled boiled water. I =

          exposed the containers to light to deliberately promote =

          germination. After 5 to 6 weeks germination had occurred =

          with all seeds, with some germination occurring with the =

          P.alpina seed collected in 1995 thus the seed would appear =

          to maintain viability for longer periods than we have been =

          lead to believe. Once germination had occured it was simply =

          a matter of transfering the small seedlings onto compost =

          using a small pipette. I am sure this method could be used =

          for other species of European Pinguicula other than P.alpina =

          and P.vulgaris.
          =

          This method may be of use to germinate other difficult to =

          germinate seed or seed requiring stratification. Earlier =

          this year Eric Green mentioned Allen Lowries method he uses =

          to germinate difficult Northern Australian Utrics and South =

          American Genlisea. He has written to me on the same subject =

          and think he wrote an article in the Aussie CP journal. =

          Basically he maintains high temperatures (25=B0C plus) and =

          water the pots from above 3 times a day. I suspect this =

          overhead watering may disperse germination inhibiting =

          chemicals such as ABA from the seeds. When pots are treated =

          normally i.e. watered from beneath using the tray system, I =

          suspect that the surface film of water on the compost =

          contains many dissolved organic chemicals from the peat and =

          also inorganic salts. This solution is probably not very =

          effective in dispersing germination inhibiting substances. =

          Thus to get some species of CPs which have constant water =

          movement in their natural environments germination maybe =

          enhanced by suspension in water or through frequent over =

          head watering.
          =

          This brings me back to Adrian Arnolds recent posting on =

          avoiding green slime, and whether the germination he has =

          achieved is through avoiding the slime or whether the =

          overhead watering has dispersed inhibiting substances. =

          Certainly Adrians technique to avoid slime is similar to =

          Lowries germination method.
          =

          Looking forward to comments.
          =

          Regards
          =

          Loyd



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