Growth characteristics and needle structure in some interspecific hybrids of Abies cephalonica Loud

Abstract

The height growth dynamics of three interspecific crosses with Greek fir (Abies cephalonica Loud.) acting as mother and a control variant from self-pollination were followed throughout a period of 30 years. The hybrid combination A. cephalonica × A. nordmanniana exhibited enhanced growth relative to the selfed control at stage of 4-year old seedlings already, whereas the hybrid A. cephalonica × A. alba only at stage of 9-year old saplings. At age of 30, the heterotic growth persisted only in the latter, the hybrid A. cephalonica × A.nordmanniana was comparable in height growth parameters with a selfed control. The interspecific cross A. cephalonica × A. numidica was remarkable by its accelerated growth during early stages of the development. At age of 4 years it has surpassed in height growth both A. cephalonica × A. alba and control but has declined profoundly during subsequent stages of its development. A conspicuous feature of the hybrid needle anatomy were abundant resin canals and reduced size of some anatomical traits of its needles. In spite of variable growth potentials, all the three interspecific hybrids are recommended for planting in Slovakia, especially at densely polluted areas where domestic silver fir cannot withstand emission pressure.