Study idea to resolve the issue or distinguish Murraya paniculata and m exotica

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ushadi Micromini

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18-Oct-2011, 6:54:18 am18/10/11
to efloraofindia
Dear All:
it seems murraya paniculata and m. exotixca is a hot issue... for what reason... I am not exactly sure...
but it would be an easy test case to resolve...
since it grows every where in indian gardens and woods apprantly...
every body reconises it and has a story about it...
its easy to look after nd follow... 
in a thread that went on and on... I hhad proposed the following ... but it got buried in the rest of the arguments...
so I am posting what I said there here in an independent thread so that this proposal may get and independent airing... free of previous threads interpersonality discourse...


its a purely scientific endeavor....
lets start thinking.. at the end what may emerge will /may be totally different from what I wrote...

that's ok too...

Usha di: I quote myself from that thread:

" Dear all:

one thing I learned from studying cancer .... which is also a study of
structure, biology behaviour...

one thing I learned: is that we should try to keep an open mind...

things may turn out to be quite different and may surprise the heck
out of the learned minds, sometimes...

nothing is written in stone...
none of these floras.. or hortuses or whoever... went on the mountain
and returned with a burning bush...
these are not commandments from god... merely guidelines made by
experts from some local university groups or botanical gardens,  they
study hard and make deductions
BUT    what they say should sometimes be taken as a guideline and not
a commandment...
I am sure they never came to India and saw these murraya plants in
action...

may be it behooves someone/ one two a few ... from our group to do
that...

somewhere in this thread I had even agreed to collect specimen and
preserve and send for genetic analysis if someone was interested... or
had the grant monies and lab equipment and grad students to do the
research....

 so lets not fight ... but do something constructive...

may be we should have a  Murraya panniculata week.... once every 3
months, that will cover the entire year's worth of the plants
behaviour... leaf only, leaf and flowering stage,  fruiting stage and
dormancy in deep winter...
which would perhaps be different  in different parts of India...
where people will take pictures in Prescribed format, with
rulers ///    and collect twigs, plant material fruits... etc...
and press herbarium specimen... from all states of India....

and may be ceylon ... kamini grows there too...

LETS THINK ABOUT THIS....

USHA di " end quote.... this was in this thread:

http://groups.google.com/group/indiantreepix/browse_thread/thread/4eb0079f406077a2/df754f7be0e99bfa?lnk=raot#df754f7be0e99bfa




Thank you


Usha di
======================================

Gurcharan Singh

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18-Oct-2011, 11:03:09 am18/10/11
to ushadi Micromini, efloraofindia
Ushadi
Thanks for this new idea, I fear studying only morphological features of few photographs won't help much. As you must be aware the important decisions these days are taken on the basis of collecting data from thousands of specimens/populations regarding attributes of morphology, anatomy, embryology, palynology, and more recently DNA, RNA and proteins. This huge data is subjected to sophisticated phylogenetic analysis to generate phylogenetic trees, and the nesting of different taxa decides which two are closer and how much. supposing out of 20 taxa studied 18 are separated by at least 20 percent (or any other unit) and two by only 5 percent (or so). It would be logical to merge these two. It is only these studies which led to the merger of Apocynaceae and Asclepiadaceae, and separation of  Liliaceae into so many families. For more than 100 years or so Nerium indicum and Nerium oleander were treated as distinct species, and no one questioned it, but now that studies have shown that especially the molecular data does not support this separation, the two are merged, and no one seems to question it. The same has been true for the merger of tomato back into Solanum after nearly 250 years. 
    Yesterday I went through the revision of genus Acmella, monograph being based on phylogenetic trees and nesting of species to take his decisions, and producing a good revision. I have yesterday provided key to nearly eight species which were earlier considered as single Spilanthes acmella. It is also uploaded on our website.

Yes this can be taken as a subject of thesis where the person studies all species of Murraya. There are 38 names and only 8 recognised species.  A multi-attribute analysis mainly molecular of all these taxa can help to decide how many clusters (and consequently taxa should be recognised.

 Molecular data can some times throw interesting results. I had described a new species Tragopogon kashmirianus, and was a tetraploid, intermediate between other two species in Kashmir T. porrifolius (red florets) and T. dubius (yellow flowers), both diploids. This hybrid was the result of hybridization and subsequent duplication of chromosome number (amphiploidy). since this species shared features of both these species and was independent (setting seeds), it deserved a distinct species recognition. I published this but was always in doubt, since a tetraploid hybrid between these two species was already known in USA, under the name T. mirus. My worry was how can same two species give rise to two different species through hybridization and subsequent tetraploidy. Lucky for me a paper was published in Botanical Society of  America in 2006, in which 5 different authors (one from Kashmir) did detailed molecular analysis on different species and concluded that T. mirus and T. kashmirianus are quite distinct, and real relief came to me when they discovered that T. dubius of Kashmir is distinct from T. dubius of USA. The parents are not clear, but is clear that two species are distinct. 


  .  .     

-- 
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://people.du.ac.in/~singhg45/ 
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