"conidial" terminology

RIDLEYG at fri.cri.nz RIDLEYG at fri.cri.nz
Wed Feb 19 15:56:03 EST 1997


     When I was an undergraduate in the last years of the 70s and beginning 
     of the 80s I was taught mycology by what I would describe now as a 
     very conservative plant pathologist. It was typical of what much of 
     undergraduate teaching, simply the rote learning of names and facts. 
     It was not until I was a postgraduate that I discovered that the 
     sciences, including mycology, were in ferment. My time of entry into 
     mycology saw the publishing of the 'Whole Fungus', a new addition of 
     the 'Dictionary of Fungi' and Eriksson's revisions of the bitunicate 
     Ascomycetes. New ideas that never saw the light of day in our 
     undergraduate course. In my own way I took most of this on board and 
     over one small word I made a personal stand. The word was conidium and 
     I rejected it. My reasoning was that the propagule was a spore 
     therefore it should be called a spore, just as occurred in the 
     basidiomycetes with basidiospore, and the ascomycetes with ascospores, 
     I felt that in the Fungi Imperfecti/Deuteromycetes that these 
     propagules should be called conidiospores for consistency. I know do 
     not remember if I came to this conclusion independently or took my 
     lead from my undergraduate text 'Introduction to Fungi' by John 
     Webster (2nd ed, 1980, p.89) where he says "Conidiospores, commonly 
     known as conidia, are asexual reproductive structures." So since then 
     I have simply substituted conidiospore for conidium.
     
     Recently I have prepared a couple of description of newly recorded 
     fungi for New Zealand and used the term conidiospore and these have 
     gone through referring and have been published. However, the latest in 
     the series has been returned by a referee with conidiospore crossed 
     out and conidium substituted and with the comment that conidiospore is 
     a "neologism" not recognised in "Ainsworth and Bisby's Dictionary of 
     Fungi" and that it was superfluous because it replaced the well 
     established mycological term conidium. This sent me scurrying to the 
     "Dictionary" and sure enough in the 8th edition (1995) there was no 
     sign of conidiospore, nor for that matter in the 7th (1983). However 
     it was in the 6th (1971) and in the 2nd (1945). It was also in Snell 
     and Dick's "A Glossary of Mycology" both the 1st (1957) and in the 
     revised ed (1971). So it would appear that with the publication of the 
     7th edition in 1983 conidiospore was expunged from the language. 
     
     But my difficulty with conidium still exists. We can for instance 
     describe an asexual spore ontogenetically as a thallospore and 
     morphologically as a amerospore - we just do not call it a spore.
     
     With the general acceptance of conidium a series of back formed words 
     have been brought into existence. Thus a conidium is produced by a 
     conidiogenous cell which may be supported on a conidiophore or housed 
     in a conidioma. The next logical step would seem, to me at least, to 
     replace the term Fungi Imperfecti or Deuteromycete with Conidiomycete 
     or Conidial Fungi. But again the Dictionary appears to be setting the 
     lead by grouping these anamorphic fungi in the "Mitosporic Fungi". 
     Thus a conidium is a mitospore which is correct just that mitospore is 
     a very old word.
     
     So my options are:
     
     1. Accept the status quo, ie conidium/ conidiogenous cell/ 
     conidiophore / conidioma/ Mitosporic Fungi
     
     2. Simple continue to substitute conidiospore for conidium on the 
     bases that it is an existing word.
     
     3. Use conidiospore but try and bring the other terms into line eg a 
     conidiospore must be produced on a conidiosporous cell which may be 
     supported by a conidiosporophore or housed in a condiosporoma.
     
     4. Accept the cytologically correct name of mitospore and substitute 
     it for conidium thus mitospore/ conidiogenous cell/ conidiophore / 
     conidioma/ Mitosporic Fungi.
     
     5. Accept mitospore but dump all the conidio prefixes in favour of 
     older more neutral term eg mitospore/ sporogenous cell/ sporophore/ 
     fruitbody or fructification/ Mitosporic Fungi.
     
     6. Accept mitospore and Mitosporic Fungi but bring all the terms into 
     line with the prefix mito, thus mitospore/ mitosporogenous cell/ 
     mitosporophore/ mitoma/ Mitosporic fungi. This would also bring it in 
     to line with the ascomycetes and basidiomycetes
     ie ascospore/ ascus/ ascogenous cell/ ascoma/ Ascomycota
     and basidiospore/ basidium/ basidioma/ Basidiomycota
     
     I would like to hear discussion on this. I do not claim to be an 
     expert here but I often feel that when it comes to language we chuck 
     scientific logic out of the window for supposed historical usage and 
     stability. This results in terminology that has to be rote learned as 
     opposed to being derived eg conidium only means dust but mitospore 
     means a spore produced by mitosis. Thus the language becomes a 
     password by which you enter the secret scientific world rather than as 
     keys to knowledge.
     
     -----------------------------------------------------------
     Dr Geoff Ridley                                   
     Mycologist/ Forest Pathologist
     
     New Zealand Forest Research Institute          
     Private Bag 3020                                  
     Rotorua, New Zealand
     
     e-mail: ridleyg at fri.cri.nz
     Phone:  +64 7 347 5899
     Fax:    +64 7 374 5333
      
     
     
     
     



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