ASYMMETRICA-FASCICULATA 475 



Occurrence and Significance 



Penicillium gladioli is commonly found on gladiolus corms, and under 

 some storage conditions may be responsible for substantial losses due to 

 rot. It is occasionally isolated from soil. The species appears to be 

 latently pathogenic to other plants producing fleshy root stocks or bulbs. 



For controlling the Penicillium-rot of gladiolus corms, Machacek (1927) 

 recommended the following measures: care m digging, dry storage, dust- 

 ing with copper carbonate or copper sulfate, periodic removal of diseased 

 corms, and judicious selection of corms for planting. McCulloch and 

 Thom (1928) reported the use of mercuric chloride and commercial fungi- 

 cides as means of control. Wliite (1934) obtained good results with a 

 mercury ammonium silicate dip. Dodge and Laskaris (1941) found P. 

 gladioli commonly associated with the Botrytis core-rot in gladiolus; 

 recommended control measures included stringent field and storehouse 

 sanitation, care in digging, and careful drymg of all corms, especially 

 those harvested in wet weather. 



Limber (1944) isolated Penicillium gladioli from a diseased yam {Dio- 

 scorea sp.) from Cuba. 



In one of their surveys of different fungi for the production of anti- 

 biotics, Wilkins and Harris (1943) reported Penicillium gladioli to produce 

 an antibacterial substance that inhibited Bacterium coli, Staphijlococcus 

 aureus, and Pseudomonas pyocyanea. Subsequently Brian, ei at. (1946a) 

 re-examined the species and found that a substance possessing both anti- 

 fungal and antibacterial properties was produced. The antibiotic was 

 designated "gladiolic acid". Methods for producing and concentrating 

 the active substance were briefly noted, as were also its chemical proper- 

 ties. The substance prevented the germination of Botrytis allii conidia at 

 a concentration of 2Mg./ml. 



Penicillium ochraceum Series 

 Outstanding Characters 



Colonies with conidial areas variously in yellowish olive, buffy olive, or 

 buffy brown in some strains, in others showing lighter shades near 

 sandy brown or pinkish buff, but never developing gray-green, blue- 

 green, or yellow-green shades. 



Conidiophores mostly arising independently from the substratum or from 

 a well developed aerial felt to produce a deep velvety effect, variable in 

 length up to 400 to 500/i, with walls roughened; not infrequently ag- 

 gregated into definite fascicles, particularly in older cultures on malt 

 agar. 



