Lecture III — 45 — Fungal Endophytes 



for the mycorrhizae. Auret (1930) found a Phoma sp. in Lunularia 

 in South Africa; Ridler (1922) in Pellia and (1923) in Lunularia 

 in England, but was not certain in the latter case that Phoma was 

 the true endophyte. 



Mycelium Radicis : — The older names of Fusarium and Rhizoc- 

 tonia were supplanted in 1909 by Burgeff's new name of Orcheomy- 

 ces which he applied to fifteen orchid fungi. The name of "Orcheomy- 

 ces" is attractive : it is short and expressive, but apparently only 

 Nobecourt (1923) adopted it; and in 1911 Burgeff had abandoned 

 the name and adopted Mycelium radicis in its stead. This name 

 is of more general application but it is awkward, even though abbrevi- 

 ated to M. r., and it violates the Linnaean principal of binomialism. 

 Melin adopted the designation for his isolates, M. r. abietis from 

 spruce and M. r. silvestris from pine. Most of these fungi are basidio- 

 mycetes but M. r. atrovirens is a phycomycete and a parasite that 

 forms pseudomycorrhizae (Melin, 1921). Associated with this 

 fungus may be another distinguished by a mycelium of coarse, lus- 

 trous, jet-black hyphae that radiate from the mantle of a mycorrhiza, 

 a fungus which was named M. r. nigrostrigosum by Hatch (1934). 

 This fungus was apparently figured by Gibelli (1898) and is de- 

 scribed by Mangin (1899). Bjorkman (1941) found both these 

 fungi in Sweden, under stands of spruce, pine and birch. 



As the designation Mycelium radicis usually (but not always) 

 refers to Basidiomycetes, so the recently prominent Rhizophagus 

 refers to Phycomycetes. Butler's (1939) paper on this genus had 

 already been referred to in an earher paragraph.* 



Conclusion: — In conclusion, we may say that there seems to be 

 an unnecessary emphasis laid on the fungal endophyte. If it were 

 shown that one fungus is more capable of proteolysis than another 

 and therefore better able to invade tissues of a plant ; or if another 

 fungus had a greater supply of diastasic enzyme and was conse- 

 quently better fitted to be an orchid symbiont ; or if yet another fungus 

 had rich provision of N cation or phosphorus-complex and was 

 therefore a richer "booty" for the "mycorrhiza to capture", there 

 would seem to be some point in the emphasis laid on fungal identifica- 

 tion. But in all cases it is simply a case of : A occurs on B, or C 

 occurs with D ; when, as a matter of fact, we know that A and C — 

 and E and G, for that matter — can all occur in the mycorrhiza of B 

 at the same time. 



*LiHNELL finds that M.r. nigrostrigosum is the same as Cenoccoccum 

 graniforme (Symbol.bot.UpsaUens. 5(2), 1942). 



