Useful information needed to understand the world of orchids..thanks Pankaj ji
On Thu, Oct 3, 2013 at 7:13 PM, Gurcharan Singh <[email protected]> wrote: > Thanks Pankaj ji for this very useful information. > > Dr. Gurcharan Singh > Retired Associate Professor > SGTB Khalsa College, University of Delhi, Delhi-110007 > Res: 932 Anand Kunj, Vikas Puri, New Delhi-110018. > Phone: 011-25518297 Mob: 9810359089 > http://www.gurcharanfamily.com/ > http://people.du.ac.in/~singhg45/ > > > On Thu, Oct 3, 2013 at 6:45 PM, Pankaj Kumar <[email protected]>wrote: > >> Orchids have lightest seed among the angiosperms and one of the reason >> for that is the lack of endosperm, that is the, reserved food >> material. So orchid seeds need external support to germinate. Here >> comes the role of mycorrhiza, a kind of fungi. >> >> Fungi in turn are always very specific as we know that there are very >> specific fungi that infects specific fruits. This compatibility >> depends on the ability of the fungi to infect another organism, the >> composition of the cell wall of both. In case of orchids, first >> infection is when fungi gets associated with the seed. Such fungi or >> mycorrhiza are of two types, one which are very generalized, i.e., >> they can infect seeds from many species; second which are very >> specific, as they can infect very specific seeds. These fungal >> filaments or mycorrhiza links seeds with another plant and kind of >> helps in transfer of food from other plant (live or dead) to the >> orchid seeds. One more fact is, there could be more than one >> mycorrhiza associated with the seeds in one time. >> >> Now where this fungi is found is also very specific, a fungi growing >> in warmer temperature will not be found in cooler areas; a fungi >> growing in very high humidity will not be found in drier areas; and >> one of the most specific thing is, a fungi that is found in the litter >> of SAL tree leaves, may not be found on the TEAK tree leaves. >> So if there is a specific fungi which can infect orchid seed and is >> found in a SAL forests, then this also implies that the orchid will be >> found exclusively in the SAL forests and nowhere else. If the orchid >> and fungi have very generalized requirement then they tend to be very >> widespread. >> >> To meet up with all this fungal requirement, one orchid fruit holds >> millions of seeds, but yes the chance of survival is very low, but >> even if it is 5 % thats enough for every year. >> >> Fungi also acts as a kind of biological control otherwise with so many >> species and so many seeds, there would have been orchids growing in >> every corner of the world!!! >> >> NOTE: I am trying to use very simple and not technical words, so as to >> make it understandible to every one. >> Please feel free to question back if you dont understand any point. :) >> Best regards >> Pankaj >> >> >> >> -- >> *********************************************************** >> Pankaj Kumar, Ph.D. >> IUCN-SSC Orchid Specialist Group Asia >> >> Office: >> Conservation Officer >> Orchid Conservation Section >> Flora Conservation Department >> Kadoorie Farm and Botanic Garden (KFBG) Corporation >> Lam Kam Road, Tai Po, New Territories, Hong Kong. >> Residence: >> 151, 1st Floor, Tai Om Tsuen >> Lam Tsuen, Tai Po, New Territories, Hong Kong. >> >> email: [email protected]; [email protected] >> Phone: +852 2483 7128 (office - 8:30am to 5:00pm); +852 9436 6251 >> (mobile). Fax: +852 2483 7194 >> >> -- >> You received this message because you are subscribed to the Google Groups >> "efloraofindia" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/indiantreepix. >> For more options, visit https://groups.google.com/groups/opt_out. >> > > -- > You received this message because you are subscribed to the Google Groups > "efloraofindia" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/indiantreepix. > For more options, visit https://groups.google.com/groups/opt_out. > -- Regards, Dr. Nidhan Singh Assistant Professor Department of Botany I.B. (PG) College Panipat-132103 Haryana Ph.: 09416371227 -- You received this message because you are subscribed to the Google Groups "efloraofindia" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/indiantreepix. For more options, visit https://groups.google.com/groups/opt_out.
