Fusaria of Potatoes 



237 



Hab. In stems and rotten tubers of Solanum tuberosum, in Germany 

 and in the United States. 



Differs from F. clavatum mainly by indistinctly clavate conidia and by 

 presence of denser hues of red color in substratum. 



Measurements of conidia on various media are as follows: 



On slightly acidified hard potato agar, culture twenty-four days old; 



conidia from pseudopionnotes: 



Conidia: 1 -septate, rare 



3-septate, 11 per cent, 32.3 x 4.3 (27-37 x 4.1-4.9) n 

 4-septate, 14 per cent, 36 x 4.5 (32-42 x 4.3-5) fi 

 5-septate, 75 per cent, 39.2 x 4.7 (31-46 x 4.3-5.7) y 

 6-septate, few, 53x5.8/* (only one measured) 



Fig. 41. — Fusarium discolor, a, Conidia from a small plectenchymic sporodochium; b, 

 conidia from pseudopionnotes from 15-days-old culture on slightly acidified hard potato agar; 

 c, conidia from 81 -days-old culture on red raspberry cane plug; d, conidia from 86-days-old 

 culture on potato stem plug; e, conidiophores from aerial mycelium from 81-days-old culture 

 on red raspberry cane plug: F, conidiophores from minute sporodochia from M-days-old culture 

 on potato stem plug; g, conidia from mycelial growth from 41 -days-old culture on ryi iraw; 

 h, conidiophore from pseudopionnotes from 15-days-old culture on slightly acidified hard potato 

 agar; i, pseudopionnotal conidia from 9-days-old culture on hard lima-bean agar; j, intercalary 

 chlamydospore from culture on corn agar 



On red raspberry cane plug, culture seventy-two days old; conidia from 



minute sporodochia on aerial mycelium: 



Conidia: 1- and 2-septate, rare 



3-septate, 27 per cent, 30 x 4.4 (10 -49 x 3.7 -4.8) y 

 4-septate, 24 per cent, 36 x 4.6 (26-40 x 3.9-5.9) y 

 5-septate, 49 per cent, 40 x 5.2 (32-50 x 4.0-5.0) y 



