Genetic variation in resistance to Dreyfusia nordmannianae Eckst. infestations in Abies nordmanniana (Stev.) Spach

• Published in: Forest ecology and management Vol. 165; no. 1; pp. 271 - 283
• Main Authors: Nielsen, Ulrik Bräuner, Kirkeby-Thomsen, Arne, Roulund, Hans
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.07.2002; Elsevier
• Subjects: Adelgid; Agronomy. Soil science and plant productions; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Genetic variation; Genetics and breeding of economic plants; Heritability; Pest animals; Pest resistance; Resistance; Varietal selection. Specialized plant breeding, plant breeding aims; Denmark; Scandinavia; Europe; Resistance; Heritability; Adelgid; Genetic variation; Genetic selection; Aphidoidea; Genetic variability; Insecta; Genetic diversity; Forest tree provenance; Abies nordmanniana; Genetic determinism; Adelgidae; Pest; Homoptera; Artificial forest stand; Arthropoda; Insect resistance; Softwood forest tree; Gymnospermae; Pest resistance; Coniferales; Spermatophyta; Intraspecific comparison; Inheritance(genetics); Invertebrata; Infestation
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/S0378-1127(01)00659-4

Nordmann fir ( Abies nordmanniana (Stev.) Spach.) is the main tree species for Christmas tree production in Denmark and adelgid attack is a severe problem. Genetic differences between Nordmann fir provenances, families within provenances and their suitability as host plants for the silver fir woolly adelgid ( Dreyfusia nordmannianae Eckst.) were investigated based on artificial infestations of 63 families originating from three provenances and four provenance samples a total of 2100 seedlings planted in a single field trial. Counts of adelgids, curling of needles due to adelgid attack together with flushing and several growth traits were measured in each tree for 2 consecutive years. The artificial infestation was very efficient, with 97% of the trees infested. Family mean infestation levels ranged from 69.5 to 100% for sistentes in the first year. Very pronounced and significant family differences were seen after the year 2 assessments. Estimated heritabilities, and genetic variation among families showed a much lower level for the adelgid counts than for flushing and growth traits. Strong differences in needle curling were seen for the same infestation levels of adelgids, indicating differences in tolerance among families. Traditional backwards selection based on family means and seed orchard establishment with moderate selection intensities can reduce the future damage level but not eliminate the adelgid problem.