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Report, 1976

Flowering in a seed orchard of Pinus silvestris L.

Jonsson, Alena; Ekberg, Inger; Eriksson, Gösta


Flowering phenology and flowering frequencies were investigated in clones of Swedish and Finnish origin growing in a pine seed orchard at Långtora (lat 59°43´, long. 17°08`, alt. 15 m). One purpose was to estimate the gene contribution of individual clones to the progeny. The frequencies of female and male strobili were estimated in 1973-1975. The onset and duration of both female receptivity and pollen dispersal were recorded. The pollen density in the seed orchard was estimated. Great clonal variation prevailed in the seed orchard with respect to the frequency of female and male flowering as well as the onset and duration of female receptivity and pollen dispersal. A good agreement in flowering frequencies and phenological characteristics of the clones between different years was observed. The great vaiation in onset and duration of receptivity and pollen dispersal from year to year was influenced to a great extent by the prevailing temperature conditions in the spring, different years. The calculations of the genetic composition of the progeny revealed that the gene contribution of the analysed clones varied considerably. This was mainly due to differences in the frequency of flowering.


seed orchard; Pinus sylvestris L.; flowering; clones; pollen

Published in

Studia Forestalia Suecica
ISBN: 91-38-03190-6
Publisher: Skogshögskolan