Variation in the position of resin canals in the needles of Abies species and provenances

Abstract

The position of resin canals in the needles of Abies species, hybrids and provenances were studied by sampling 21-year-old plants in a species and provenance field experiment. It was found that at an early age all species and provenances develop needles with marginal resin canals. However, in the hybrids and also in some species and provenances, 2 types of adult tree were distinguished: a) trees with marginal resin canals throughout the crown; and b), trees with marginal resin canals in the lower part of the crown followed by a transitional zone where all stages are manifested; finally the position becomes median in the needles in the rest of their crown. The frequency of the 2 types of tree varies between species and hybrids and also among provenances within species. The position of the resin canals and the variation detected is discussed with regard to its origin and its significance to the taxonomy and evolution of the genus Abies.