STUDIES OF GLOMERELLA FROM DIFFERENT HOSTS. 51 



RIBES OXYACANTHOIDES (GOOSEBERRY) . 



Glomerella cingulata (Stonem.) S. and v. S. 

 Gloeosporium ribicolum Ell. and Ev. 



On July 5 decaying gooseberries were found at Arlington Farm, 

 Va. Some of these berries showed acervuli of Gloeosporium ribicolum 

 Ell. and Ev. and others developed acervuli when placed in a moist 

 chamber. 



Test tube cultures were made by transferring conidia from these 

 berries. The growth in the tubes was of the usual appearance of 

 Glomerella cultures. On July 14 acervuli were present in three of 

 the four tubes. They were few in number and located about the 

 point of inoculation. The development of the mycelium was rather 

 more scanty than usual and showed little indication of the dark color 

 which frequently develops in old cultures. These cultures never 

 developed more acervuli, but small groups of perithecia appeared 

 which were either sterile or immature. Transfers were made from 

 each of these tubes to four others. These cultures developed very 

 few acervuli and conidia. Two of these cultures developed distinct 

 stromatic masses of perithecia, all fertile and producing typical 

 ascospores. The massing of the perithecia in these two cultures was 

 very conspicuous, as the perithecia of Glomerella are most frequently 

 either scattered or but slightly aggregated. 



Apples were inoculated with ascospores from these cultures, as 

 described later, and the cultures made from the tissues of these 

 decayed apples produced large quantities of perithecia but very few 

 and minute acervuli. The conidia developed were mostly scattered. 

 Plates poured from the cultures from the inoculated apple had a very 

 characteristic appearance. The perithecia developed in great 

 numbers and were quite evenly distributed throughout the medium 

 instead of being aggregated in masses. Acervuli developed on the 

 surface of the medium at certain points, but they were very small and 

 inconspicuous. The perithecia appeared to be rather larger and 

 thicker walled than usual in Glomerella, but the asci and spores 

 as well as conidia agreed in all respects with those from other hosts. 

 The passing of one generation of the fungus through the apple had 

 apparently increased its vitality in some way, as it grew much more 

 luxuriantly in the cultures made from the apple and developed 

 perithecia and conidia much more abundantly. 



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