[OGD] Are orchids parasites?
I have a question. I have always understood from reading books about orchids that they are not considered parasitic. However, I came across a newspaper article from Malaysia that states just the opposite. I would be interested in comments from those more knowledgeable about orchids than me (that would be just about everyone). Thanks http://thestar.com.my/lifestyle/story.asp?file=/2004/9/7/features/petalspurs ec=features Here's an excerpt: ...For all their diversity, orchids share one common trait: they rely solely on other organisms, particularly fungi, to survive b a characteristic which Jutta says is quite distinctive and serves as a source of confusion to scientists.B Fungi play a crucial role in the biology of many plants because they convert oxygen to compounds that plants can use to grow, but orchids depend on fungi well into maturity. Beneath their good looks, orchids are parasites, says Jutta. This conclusion was established only at the beginning of the last century, and after much debate, it has finally been accepted and scientifically proven.B Orchids use fungi as a means of nutrient transport. The plant even produces sugary matter for the fungi, which feed on carbohydrates, to attract them.B Once the fungus penetrates a certain point within the plant's cells, says Jutta, the cells will secrete an enzyme that breaks down the fungal tissues, keeping the fungus in check and preventing it from invading the plant further.B The dissolved fungal tissue is then broken down into vitamins, fatty acids and carbohydrates which the plant uses for its own growth.B This cycle is repeated over and over, and each cell is re-colonised several times. This process, she adds, begins as soon as an orchid seed germinates.B When a seed's outer shell is broken, it is 'invaded' by a fungus, but the seed contains the enzyme that keeps it in check, not allowing the fungus to destroy it.B Once this happens, the fungus is not killedbut it simply becomes a vessel through which the orchid derives nutrients for its own development, says Jutta.B -- www.pollenatrix.com Botanical discipline, daily. ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
Re: [OGD] Are orchids parasites?
Hello Sandy, From various sources (online and in books) I have come to understand the following: 1) Most orchids need fungus to germinate. This is a fight of life and death. If the fungus is too strong, it can kill the seed. If the seed can keep the fungus in check, it survives and grows. 2) From germination, an orchid seed relies on the fungus for nutrition. This period can be long or short, depending on genera and species. Phals quickly put out leaves and can flower in about 4 years. Some slipper orchids could take many years before putting up a leaf, and many more before flowering. Also, there exist orchids who are not able to make chlorophyl at all, and rely 100% on fungus to feed them. Upon maturity, some orchids tend to eliminate fungii from their roots. Others tend to keep a colony handy. 3) Even orchids who have green leaves and produce food by photosynthesis can revert to their earlier phase of fungal dependency should conditions force them into prolonged dormancy underground. If the orchid had eliminated all fungii from its roots, it can always invite a new colonization. So, in bad conditions, some orchids will simply go underground and live off of fungus until it feels conditions have ameliorated above, and will put out new leaves and flowers. This is especially true of terestrial species with tubers. Epiphytes might function somewhat differently. (I got most of my information out of books on European native orchids. Some websites are cited in the following links on symbiosis between fungus and orchids). Sincerely, Marianne To see some disscussions and links: http://ukorchidforum.proboards24.com/index.cgi?board=orchidchataction=displaynum=1090921407 http://ukorchidforum.proboards24.com/index.cgi?board=orchidchataction=displaynum=1093603565 ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] Re: Sterilizing
In a message dated 9/7/04 6:23:55 AM, Bob Scully writes: I respectfully take exception to the apparently dominant opinion on the efficacy of bleach as a reliable virus sterilant for orchid pots and cutting instruments. Thanks. Let's hear it for the self-cleaning oven, periodic sample testing, disposable blades, and bleach for non-suspect plastic pots labels. (If a plant in a plastic pot tests positive, I throw the whole thing away, pot all.) Iris If we see light at the end of the tunnel, It's the light of the oncoming train. Robert Lowell (1917-1977) ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
Re: [OGD] Are orchids parasites?
Ms. Gillians, The context in which the reporter used the term parasitic is not, in my mind, a contradiction, but rather an indication that she knows little, and understands poorly, of what she writes. A parasite is a living organism that takes nutrients from another living organism and generally permits the host to survive, often through multiple generations of the parasite. The news article (which was read in its entirety) seems to refer to the orchid taking nutrients from fungal tissue killed by the host. This is not parasitism, strictly speaking. In zoology, there is a fine discrimination between so-called true parasites and parasitoids, the later killing the host as a consequence it completing its life cycle. In botany, there is even a finer line between parasites and their hosts, usually taking the form of symbioses or mutualisms; this is the relationship of some orchids with some fungi, but apparently not all nor always. To confuse matters even more, what may start, or appear to start as a parasitic relationship does not necessarily remain, but may become a symbiotic relationship, or a reversed predatory role. In recently reported research there is evidence suggesting that the question of whether a fungus or the orchid are parasites upon each other is challenged, reducing traditional thoughts to semantic arguments as the biological realities of orchids in the real world (i.e., outside of our collections!) become better known. The concept of predation of one plant upon another, or upon a fungus or another organism, is a non-traditional perspective and begets additional semantic problems. The difference between parasitism (or parasitoidism) and predation, too, is a fine distinction. Paul Paul J. Johnson, Ph.D. Professor of Entomology Insect Research Collection Box 2207A, South Dakota State University Brookings, SD 57007-0001 tel: 605.688.4438; fax: 605.688.4602 ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] ORCHID COLLECTION WANTED
K.Barrett, THE .WS INTERNATIONAL E-MAIL CODE INDICATES WEST SAMOA. Peter O'Byrne Sg CHRISTINA, YOU MAY GET A BETTER RESPONSE IF YOU STATED WHAT PART OF THE WORLD YOU LIVED IN. K BARRETT N CALIF, USA --I WOULD LIKE TO BUY SMALL AND OR MEDIUM COLLECTION OF ORCHIDS. [EMAIL PROTECTED] THANKS. CHRISTINA ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] Effectiveness of Bleach as an Antiviral Agent
I presume that Bob Scully's rebuttal of he antiviral effectiveness of a simple exposure to bleach [hypochlorite] originates from the Work Ethic concept that the greater the labor, the greater the reward. Regarding the torch vs. bleach, it ain't necessarily so. I have great respect for Bob's historical stewardship of the renowned Jones and Scully orchid stock, but my own background in Cell Biology, Biophysics and Biochemistry is more appropriate for the issue at hand. I find it challenging to draw upon my laboratory research career to compensate for the greater cultural prowess of my colleagues, I have Googled the entry hypochlorite and virus and found 615 PAGES of entries; all I had time to peruse concur with the total antiviral effectiveness of even short exposures to strong bleach. I hesitate to disagree with Dr. Zettler, cited as a distinguished, retired Floridian virologist, but I take some pride in having been the most highly cited scientist in the state of Florida for a stretch of over a decade before my own retirement. I suggest that the authorities cited by Bob have been overly cautious in recommending an unnecessarily great safety margin in their advisories. My own grasp of the stability of biological entities such as cells, membranes and viruses makes it inconceivable that they can resist the chemical action of hypochlorite, especially coupled with high pH. This view is reinforced by my observations of how effectively bleach destroys organic residues on clay pots. The suggestion that TSP could substitute for bleach as a viricide, a common misconception among orchid cultivators based on repeated assertions, is like sending soldiers to war with pea shooters instead of guns. Incidentally, it is impossible to maintain a supersaturated solution of TSP, for if it is truly supersaturated the excess TSP will crystallize out. Bert Pressman ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] where to ship your orchid collection - Samoa or Iowa
K. Barrett, Peter : Christina Mesenbrink who wrote: I WOULD LIKE TO BUY SMALL AND OR MEDIUM COLLECTION OF ORCHIDS. lives in Iowa, if I am not wrong,. Regards, Viateur ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] Greater New York Internatioan Orchid Show dates?
Hi everyone, I am planning to attend the 2005 Greater New York International Orchid show and really need to get the dates nailed down so I can start getting plane tickets. There are no dates on the GNYOS website. I found a vendor who has the dates listed as March 30 through April 3 2005 - can anyone with a connection to the GNYOS confirm those? Thanks a lot! -Eric in SF www.orchidphotos.org ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] Re orchid mycorrhizae
For all their diversity, orchids share one common trait: they rely solely on other organisms, particularly fungi, to survive b a characteristic which Jutta says is quite distinctive and serves as a source of confusion to scientists.B I am not even close to being an orchid mycorrhizae authority, I am merely a hobbyist and my comments must be seen as such. I stand to be corrected by the mycologists, scientists, among us. It is my understanding that Mycorrhizae( root fungi, )do supply orchids with energy. It is however wrong to say that all orchids solely rely on fungi, only those incapable of photosynthesis do. Dr. H.N Rasmussen believes that orchids may use mycotrophic or phototrophic nutrition; they may use them alternately, or simultaneously where one supplements the other.. Fungi play a crucial role in the biology of many plants because they convert oxygen to compounds that plants can use to grow, but orchids depend on fungi well into maturity. Beneath their good looks, orchids are parasites, says Jutta. This conclusion was established only at the beginning of the last century, and after much debate, it has finally been accepted and scientifically proven.B As I understand it, Orchid Mycorrhizae obtain nutrients by breaking down (using enzymes) and absorbing chemical substances from their environment; then carry the nutrients into the roots of the orchid where they are being consumed. These include substances that the root itself could not extract nutrients from. One may consider the orchid parasitic on the fungus, yet at the same time it maintains a symbiotic relationship with the fungus, keeping part of it alive. This is not the same kind of parasitism people talked about before orchid mycorrhizae was seriously studied. Many believed then that orchids were parasitic on their hosts. Once the fungus penetrates a certain point within the plant's cells, says Jutta, the cells will secrete an enzyme that breaks down the fungal tissues, keeping the fungus in check and preventing it from invading the plant further.B When a symbiotic relationship exists between fungus and orchid, the plant produces phytoalexins, an induced chemical resistance to fungal infection, which may be explained as a static fungicide that keeps other non symbiotic and aggressive fungi from entering the roots, and the symbiotic one from becoming too aggressive and parasitic on the orchid. When the symbiotic fungus becomes more vigorous, the production of phytoalexins increases; like a feedback control system, keeping a balance and thus preventing the fungus from becoming parasitic on the orchid.. This cycle is repeated over and over, and each cell is re-colonised several times. This process, she adds, begins as soon as an orchid seed germinates.B Only certain cells within the roots are infected by the symbiotic fungus. The hypha go around and around within the cell wall and fuse together into a dense ball called a peloton. As the peloton is being formed, certain hypha penetrate the cell walls and infect adjacent cells to form more pelotons.Soon after the peloton is fully formed it is being consumed by the orchid and its size diminishes.i.e. fungal hypha collapse and being they are made of a hard substance called Chitin, they take longer to be consumed and can thus be seen in the cells as yellowish blobs that slowly get smaller. These blobs allows us to see how often the same root cell has become infected by the symbiotic fungus. In my hobby experience, I have never seen a cell with more than three such blobs, indicating it was infected at least three times. Not seeing more blobs, may be due to some pelotons having been totally consumed or due to the roots at some age becoming inactive. Once this happens, the fungus is not killed but it simply becomes a vessel through which the orchid derives nutrients for its own development,...snip This is true for the fungal hypha that go in and out the roots, most often through the root hairs However, the fungal hypha in the fully formed pelotons are dead , either when consumption starts, or soon after. Unable to obtain fungal cultures from them, one obtains live fungal hypha from pelotons in the making; not yet fully formed. ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] Phal. micholitzii
Hi Charles, I have Phal. micholitzii in my collection and I grow it on the warm side, that is winter night temps at 18/21: C. In summer the nights are usually around 18: C and the days at 28/34: C range. I have the plant now for 6 months and it grew 2 new leaves. It has 11 leaves and 5 inflorescenses and produced 3 flowers so far. It had a keiki when I received it and I removed it and it is also growing well. Seems mother and kid like the conditions. Regards Peter from Bloubergstrand ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] TSP
Bob; Please use spell check before posting. I assume you mean 'are' not 'a' in the end of your note. Perhaps I can enroll you in Dr. Motes English class. All is well love to Sue. Julie Warren Kelly ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] RE: WS INTERNATIONAL
The WS INTERNATIONAL is actually used for Wales. My consulting group has its e-mail here mine is [EMAIL PROTECTED] Orchids are not paying enough. Wayne THE .WS INTERNATIONAL E-MAIL CODE INDICATES WEST SAMOA. Peter O'Byrne ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] Dates for the 25th New York International Orchid Show
Eric, The dates for the 25th New York International Orchid Show will be: Tuesday April 12, 2005 - Sunday, April 17, 2005 Organized by the Greater New York Orchid Society, it will once again be at Rockefeller Center in midtown Manhattan. When the show was held at the Wintergarden of the World Financial Center the dates for the show revolved around a schedule with the show ending on Palm Sunday every year to work with their schedule. However, for numerous reasons, not the least of which making it easier for other events here in the city and elsewhere to plan, starting this year and going forward the shows will end on the third weekend (Sunday) in April. Also, for those of you who have regularly been coming to the shows, note that we have added a day to the show and will open on TUESDAY this next year instead of Wednesday. I haven't spoken with Jim Watson since the latest weather event down there, but there should be a brief report on this year's show in the October issue of Orchids Magazine. Hopefully soon we will have info up on the website. Any inquiries may be directed to me at: [EMAIL PROTECTED] In the interim, Eric, please let the individuals at the commercial site you visited know of the correct dates. Since it is our 25th we hope to do something really special. Dave Horak Show Chairman -Original Message- Date: Tue, 7 Sep 2004 08:55:34 -0700 From: Eric Hunt [EMAIL PROTECTED] To: OrchidGuide Digest [EMAIL PROTECTED] Subject: [OGD] Greater New York Internatioan Orchid Show dates? Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=iso-8859-1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: list Reply-To: the OrchidGuide Digest \(OGD\) [EMAIL PROTECTED] Message: 8 Hi everyone, I am planning to attend the 2005 Greater New York International Orchid show and really need to get the dates nailed down so I can start getting plane tickets. There are no dates on the GNYOS website. I found a vendor who has the dates listed as March 30 through April 3 2005 - can anyone with a connection to the GNYOS confirm those? Thanks a lot! -Eric in SF www.orchidphotos.org -- ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] Are Orchidz Paracites ? ? ?
Dear Orchid Addicts... The answer HAS to be an unequivocal YES! Paul J Johnson states that...A parasite is a living organism that takes nutrients from another living organism and generally permits the host to survive, often through multiple generations of the parasite. Well look what they (the seductive, enigmatic, mysterious, mesmerizing Orchids) have accomplished. They have convinced homo sapiens to rescue them from their plight of near-extinction, feed them, care for them, and even propagate them. By Paul's definition, they are. They take nutrients from us, their hosts, and, yes, they allow us to survive, allbeitly, much the poorer after we acquire them and design, build and maintain their artificial habitats. And due to our industriousness, we manage to see several generations of our youngsters by the time our fascination wears thin. Known as one of the most complex of the plant kingdom, I'd say, parasites or not, they have done pretty well for themselves. Barbara ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] IOSPE Brazil Trip
Dear OGDS I am pleased to announce that my orchid safari to Brail is now online at http://www.orchidspecies.com/brazil.htm Many orchid plants in flower and many habitat shots of rupicolus Brazilian orchids from Minas Gerais and hot to cool growing epiphytes from Sao Paulo state. The trip was made with the Brazilian orchid experts, Marcos Campacci.,. Dalton Baptista and Americo Neto in may of this year. Check it out and let me know what you think. ENJOY! Jay Pfahl http://www.orchidspecies.com 4785 species in 527 genera ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
Re: [OGD] IOSPE Brazil Trip
Thanks, Jay, for one hell of an armchair trip. I returned tired but curiously rested. I like to see how orchids are growing in their natural surroundings, and found your pages fulfilling in that respect. Thanks for sharing your journeys with us, and I'm sure others on OGD would appreciate this as well. Regards Dave - I am pleased to announce that my orchid safari to Brail is now online at http://www.orchidspecies.com/brazil.htm An honest politician is one who, when he is bought, will stay bought - Simon Cameron ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
