thin-layer chromatography (TLC) of all extracts, and den- 

 sitometric quantification of isolated sugars followed the 

 methods described by Martin and Welch (1975) and Welch 

 and Martin (1972). 



Data from the needles were analyzed as a balanced fac- 

 torial design using standard biometric techniques. Bark 

 sugar data required the following model for an unbalanced 

 factorial analysis (Snedecor 1956): 



Y.ji, = jA + Ci + Sj + CSij + Tf, + Eiji, 



where 



Yy-j^ = dependent variables 

 pL = mean 



Ci = grouping of disease class and of bark samples (Cj 

 = diseased versus nondiseased; C2 = bark 

 samples, 1 to 4 locations) 



Sj = seasons 



CSii = interaction between seasons and disease and bark 

 Tj^ = trees. 



RESULTS 



Sugar concentrations in needles of cankered and canker- 

 free trees were indicative of the influence of seasons and 

 of physiologic age (table 1). With the exception of sucrose, 

 sugar levels, when considered collectively for all needles, 

 showed a response to season through highly significant dif- 

 ferences (p = 0.05) in the season means. Sucrose showed 

 no statistically significant differences and less than half 

 the variation found in the other sugars. Amounts of 

 sugars within the November, February, and September 

 collections decreased in the order fructose>glucose> 

 sucrose>raffinose>stachyose. However, in the June collec- 

 tions, amounts of fructose were found to be similar or 

 slightly greater than those of glucose. The seasonal pat- 

 terns of amounts of fructose, glucose, and sucrose in all 

 age classes of needles were similar, with the greatest 

 amounts available in the needles sampled in the periods of 

 slow tree growth (fall and winter) and the least amounts 

 at the end of the accelerated growth period (June). 



Table 1 — Average concentrations of sugars in needles of blister rust-diseased and rust-free 

 western white pines at four times during a growing season 



Sugar (mg/g dry tissue)^ 

 Tree Needle 



status 



age 



Fructose 



Glucose 



Sucrose 



Raff! nose 



Stachy( 









November 









Diseased 



Current 



17.4 



16.2 



11.6 



7.0 



0.0 



trees 



1 year 



16.8 



14.8 



13.6 



8.1 



0.0 





2 years 



16.8 



14.5 



11.7 



7.1 



0.0 



Rust-free 



Current 



16.2 



15.0 



13.3 



7.5 



0.0 



trees 



1 year 



15.3 



14.4 



' 13.2 



7.5 



0.0 





2 years 



15.5 



13.5 

 February 



13.8 



6.6 



0.0 



Diseased 



Current 



13.4 



11.7 



12.5 



11.3 



3.2 



trees 



1 year 



14.7 



12.1 



9.9 



10.6 



2.9 





2 years 



16.0 



14.5 



9.5 



9.9 



3.0 



Rust-free 



Current 



14.7 



13.4 



12.4 



10.9 



3.2 



trees 



1 year 



16.0 



13.9 



8.8 



9.8 



2.7 





2 years 



15.6 



13.8 

 June 



10.9 



7.8 



2.7 



Diseased 



Current 



12.2 



13.0 



11.0 



Trace^ 



0.0 



trees 



1 year 



10.6 



11.9 



12.1 



Trace 



0.0 





2 years 



11.1 



11.1 



9.9 



Trace 



0.0 



Rust-free 



Current 



13.4 



13.2 



8.2 



Trace 



0.0 



trees . 



1 year 



11.8 



12.0 



11.6 



Trace 



0.0 





2 years 



10.2 



10.3 

 September 



13.3 



Trace 



0.0 



Diseased 



Current 



17.4 



16.6 



10.6 



3.8 



0.0 



trees 



1 year 



17.8 



16.5 



10.1 



Trace 



0.0 





2 years 



18.2 



16.3 



10.3 



Trace 



0.0 



Rust-free 



Current 



16.9 



18.1 



10.3 



Trace 



0.0 



trees 



1 year 



19.8 



17.2 . 



9.6 



Trace 



0.0 





2 years 



19.5 



17.0 



10.9 



Trace. 



0.0 



■•Average of four trees, each tree quantified by eight replicate TLC analyses of each sample (Welch and 

 Martin 1972). 



2The minimum threshold for accurate measurement was found to be approximately 3 mg. 



2 



