BLISTER RUST RESISTANCE OF EASTERN' WHITE PINE IN" EUROPE 243 



Table 1. Performance of seedlings from 9 Pinus strobus sources 

 when exposed to white pine blister rust in 2 experimental plots 

 at Wageningen, The Netherlands 





Seed source 



Percentage of seedlings killed 

 by C. vi-bicola 



Our 



Collector 's 



source 



1953 plot 1954 plot 



identi- 

 fying 



r.urr.ber 



No . No . 



repli- 1957 1959 repli- 1958 1959 , 



cates insp. insp. cates insp. insp. 



52-02 Coll. 1950, Pointe 



Platon, Quebec planta- 

 tion, C. Heimburger 



"strain 26" 12 25 87 12 20 30 



52-14 Coll. 1948 and 1949 



from Dutch plantation 



at Groesbeek 12 31 83 28 21 28 



52-34 Austrian selection- 

 stand plantation by 

 W. von Wettstein 12 40 79 12 28 29 



52-36 Coll. 1951 from con- 

 trolled cross of Univ. 

 Wise, phenotypically 

 resistant selections 

 6x9 3 73 96 2 20 25 



52-37 



Ditto, 



36 x 38 



2 



No data 90 







__ 



_. 



52-38 



Ditto, 



191° x 7 



2 



No data 93 







_- 



-_ 



52-39 



Ditto, 



192 x 5 



3 



43 93 



3 



20 



23 



52-40 



Ditto, 



312 C x 38 



3 



70 100 



2 



60 



65 



52-41 



Ditto, 



314 x 18 



3 



50 87 



1 



30 



40 



Each row-plot replicate contained at least 10 seedlings 



b 



In the 1959 inspection, seedlings on the 1954 plot had been exposed 

 to rust 1 year less than those on the 1953 plot; lower levels of rust kill 

 may also be associated with relatively poor conditions for rust infection 

 in 1954. 



c 

 University of Wisconsin selection nos. 191 and 312 in Wisconsin have 



been found to be slightly above average in transmitting resistance to their 



progenies; i.e., 8 to 10% disease-free plants vs. to 7% disease-free 



plants in progenies from other trees (personal communication from Dr. R. F. 



Patton, June 20, 1969). 



