CULTURES OF HETEROECIOUS RUSTS, 



1920-21 



W. P. Fraser 



A few culture experiments made in 1920 and 1921 seem worth 

 recording, as they extend the aecial host range of Puccinia sub- 

 nitens Diet., the well-known pluriverous rust. They also clear up 

 the confusion that has prevailed in regard to the connections of the 

 aecia on Glaux maritima L. 



Telial inoculations were made by suspending germinating telia 

 above the potted host plants which had been sprayed with water by 

 an atomizer. The plants were placed in an infection box for about 

 48 hours and then removed to the greenhouse. In every experi- 

 ment several checks were kept which remained free from infection. 



Puccinia Distichlidis Ellis & Ev. 



Aecia were found to be locally abundant on Glaux maritima L. 

 near Saskatoon in the spring of 1920. Field observations left 

 little doubt that they were connected with Puccinia Distichlidis on 

 Spartina pectinata Bosc. Telial material on this host was collected 

 and gave excellent germination. Inoculations were made in the 

 greenhouse on two pots of Glaux maritima. Pycnia developed on 

 both, followed by abundant aecia. The experiments were repeated 

 in 192 1, on May 27, on two pots of Glaux maritima. Pycnia and 

 aecia followed in abundance. Inoculations of a third pot on June 2 

 were also successful. Dr. Arthur studied the material from the 

 field collections and cultures of 1920, and as a result has listed 

 Glaux maritima as an aecial host of P. Distichlidis. (See N. A. F. 

 7: Part 4, 317.) 



Arthur (Mycol. 8: 136. 1916; 9: 299. 1917) has shown that 

 Puccinia Distichlidis on Spartina Michauxiana Hitchc. has aecia 

 also on Stieronema ciliatum (L.) Raf. Field observations made 

 at Brandon, Man., indicate that this is also true in western Canada. 

 This culture adds another host species to that established by Arthur. 



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