Barbara, I have been flasking for years as an amateur, but I have seen lots of the problems you are describing. Typically, I try to replate all my protocorms with in three months after they have started swelling. They are growing well at this point in time and continue to do so in the replate flask. The protocorms you described on shrinking and nearly dry media may or may not recover. The problem is that they have dehydrated as well as the media, and if they are under stress, they will slowly start to die, they may be green and appear to be alive, but they are dying. As plant tissue dehydrates the plant, it can start to produce abscisic acid, as a result of the stress and it will start shutting down the cells and they will slowly die. The best way I found to determine if protocorms or seeds were alive or any plant tissue is alive is to use Tetrazolium. It is a dye that is metabolized by living tissue and turns it pink staining the tissue with a bright pink color. Seed biologists have used it for years to test for seed viability. Biology and Botany classes have used it as a way to demonstrate cellular metabolism.
I have used a 100 mg/l solution in a pH 7.4 phosphate buffer to test for seed viability. I place what ever I am testing in a container with the Tetrazolium solution and leave it in the dark for 24 hours. I then examine it under a microscope and see it the seeds or protocorms or roots are pink. I started using it years ago to test for seed viability as I was finding lots of seeds that I was germinating were giving me poor to no germination. I found a direct relationship between the number of seeds that stained pink and the number that germinated, if I had 5% of the seed stained I got about 5% germinations, etc. If I had no seed stained pink, I got a random sporadic germination, and I might get two or three plants out of a seed pod. It helped me realize it was not my media or methods, but the seeds quality that were the cause of the poor germination. You could use Tetrazolium to test if the protocorms in flasks like the one you described were worth your time to the replate. It will save you time and your clients money, unless they are really desparate to see the progeny of the cross and want what ever they can get out of the flask. Tom /-------------------------------------------------------------------------- | Tom Hillson Orchid Grower Specializing In | [EMAIL PROTECTED] Paphs, Pleurothallids, & Epi's | http://www.orchids.iastate.edu --------------------------------------------------------------------------- |"There is always room for one more Orchid!!" On Aug 29, 2008, at 8:02 AM, Barbara wrote: > Dear OGD Readers, > > I have recently (in the last 7 months) begun to live my dream of > being a > full time orchid flasker. Having dallied in the past with home-brew > equipment, I have built my own lab and with professional grade > equipment > and am pleased with my success thus far. My best success story is > saving > a batch of besseae flavum from sure death in flasks I received from > another lab in the hopes of bringing them back for my customer who has > been waiting for flasks of this species to offer his customers for > nearly a decade. I took a chance and transferred them to some media > from > the UK. Within just 3 weeks, I could see a difference. Instead of the > yellowing and browning they were in the process of doing, they greened > up and even started to grow. Some began proliferating (a good thing in > my book) and others started producing beautiful white-tipped, fuzzy > roots. They have since been replated onto more of this magic formula > and are on their way towards becoming beautiful, healthy, individual > plants. > > I have also received mother flasks needing work that are (were) full > of > loose protocorms. The media underneath (which only the bottom layer > had > any contact with) was shrinking and nearly dry. The protocorms were > still green but have not "jumped to life" after replating as other > protocorms have done. Conversely, I have replated freshly germinated > protocorms that literally did just that, "jump to life." I later > replated protocorms from the same mother flask and have not seen the > same vigor. They are still growing, but just not as fast. I am > beginning > to wonder if there isn't a magic sweet spot in the life cycle of a > protocorm when it is perfect for replating for total optimum growth > and > that to let them go beyond that means slower growth later on. > > An analogy I suppose would be similar to the timing of orchid > repotting. > You would refrain from general repotting in the winter, opting > instead > for the accelerated growth in the spring to jumpstart the plants into > establishing themselves in new media all summer before decelerated > growth in the fall and winter. > > I know some of you who are more enlightened than I can shed some of > that > light on this subject. I would be interested in the theoretical as > well > as practical analysis of this phenomenon. > > Thank You. > > Barbara > Always Orchids Lab > [EMAIL PROTECTED] > > _______________________________________________ > the OrchidGuide Digest (OGD) > orchids@orchidguide.com > http://orchidguide.com/mailman/listinfo/orchids_orchidguide.com _______________________________________________ the OrchidGuide Digest (OGD) orchids@orchidguide.com http://orchidguide.com/mailman/listinfo/orchids_orchidguide.com
