UBC Theses and Dissertations
Early results of the Douglas-fir cooperative progency test Bartram, Victor Cameron
In 1969, a cooperative progeny test of Douglas-fir, Pseudotsuqa menzies-ii (Mirb.) Franco, was initiated to evaluate the growth performance of progeny from selected plus trees. Using height data measured in 19 75, it is shown that the mean height of plus tree progeny is significantly greater than the mean height of the control progeny. Much of this gain may, however, be due to the heterotic effect of crossing parents from allopatric populations. The breeding value of individual plus trees showed a wide range of variation. This range was markedly reduced when the few extreme plus tree parents were excluded. An investigation of possible geographic trends showed that in only one instance did the progeny of parents of similar origin perform comparably. It is therefore concluded that, over the range of plus tree selection, geographic origin is; of little, importance in determining breeding value. Initial juvenile-mature data demonstrated that nursery height in 1969 and 1970 was significantly correlated with plantation height in 1975. As expected, 1973 and 1974 plantation heights were highly correlated with 1975 height. An attempt to predict genotype x environment interactions from the latitudinal and longitudinal displacement of the progeny from their plus tree parents proved unsuccessful. Other variables must therefore be considered before: progeny performance at a specific location can be successfully predicted.
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