Genetic variation among 62 populations of ponderosa pine was studied by comparing seedlings from all populations according to (1) growth and development of 4-yr-old seedlings in three disparate common gardens and (2) patterns of shoot elongation of 2-yr-old seedlings in a greenhouse. Genetic variation was detected among populations for 19 of the variables, most of which were intercowelated. Two principal components accounted for 60So of the total interpopulation variance. Multiple regression analyses were used to relate genetic variation in 19 variables and two principal components to the elevation and geographic origin of the seed. The regression models produced values of R2 as large as .78 and accounted for more than 40So of the [...]
