FusARiA OF Potatoes 



245 



4-septate, 49.3x5.3 (48-50 x 4.9-5.4) At, often also 5-septate, typically, 

 when mature, of from deep lichen and montpellier green (on corn meal 

 agar) to light olive-drab (on potato agar rich in glucose) and often to 

 dark blue (on potato tuber plug);^" macroconidia usually produced in 

 abundance in small sporodochia and in pseudopionnotes; chlamydospores 

 terminal and intercalary, single, in clusters, and in short chains, mostly 

 0-septate, 9.25x8.16 (8-11.3 x 7. 5-9.3)/^; aerial mycelium typically me- 

 dium short (from 1 to 4 millimeters), loose, more or less coarsely powdered 

 with conidia, and typically, on potato agar rich in glucose, of from smoke 

 gray to sometimes Charturadrab color; the substratum on the same kind 

 of medium being mostly of from tawny olive to sepia in color. 



Fig. 44. — a-i, Fusarium Martii var. viride. a, Pseudopionnotal conidia {the stippled one 

 showing dense granulation of the protoplasm masking septation), b, conidiophores (magnification 

 250 times), from 11 -days-old culture on slightly acidified hard potato agar; c, conidia showing 

 dense granulation of the protoplasm containing from small to large oil globules from 29-days-old 

 culture on rye straw; d, chlamydospores , terminal and intercalary, e, pseudopionnotal conidia,- 

 from 71 -days-old culture on potato tuber plug; f, conidiophore from 70-days-old culture on 

 potato stem plug; g, conidia, h, conidiophore, from ^'''-days-old culture on stem plug; i, pseudo- 

 pionnotal conidia from 64-days-old culture on potato tuber plug 



J-L, Fusarium Martii var. minus. J, conidia from plectenchymic sporodochium from 71- 

 days-old culture on potato tuber plug; k, sporodochial conidia from 85-days-old culture on red 

 raspberry cane plug; Ka, microconidia from aerial mycelium; l, basal part and one branch 

 of compound conidiophore from 71 -days-old culture on potato stem plug 



M, Fusarium Martii, pseudopionnotal conidia from 11-days-old culture on slightly acidified 

 hard potato agar 



^ The culture media are mentioned here merely because the colors were oftener observed on these media 

 than on others; in fact, a green color in conidia is often produced also on potato tuber plugs and on some 

 other media, and the same is true of a blue color. The color is due to color of conidia, not to color of 

 substratum alone, as can be observed under the microscope. 



