Abstract
Concerns over the reductionist nature of the domestication of forest-tree species focus on the possibility of potential genetic erosion during this process. To address these concerns, genetic diversity assessments in a breeding zone the Province of British Columbia “interior” spruce (Picea glauca × engelmanni) program was conducted using allozyme markers. Genetic-variation comparisons were made between natural and production (seed orchard) populations as well as seed and seedling crops produced from the same breeding zone’s seed orchard. The natural population sample consisted of a total of 360 trees representing three stands within each of three watersheds present in the Shuswap-Adams low-elevation zone of interior British Columbia. Small amounts of genetic differentiation were observed among the nine natural populations (4%) and this was attributable to extensive gene flow (Nm = 7). Consequently, the sum of these nine populations was considered as a baseline for the genetic variation present in the breeding zone. The comparisons between the seed orchard and the breeding zone produced a similar percentage of polymorphic loci (%P = 64.7%) while the expected hetrozygosity (He) (0.207 vs 0.210) and the average number of alleles per locus (2.7 vs 2.4) were slightly lower in the seed orchard. A total of seven natural populations’ rare alleles (P < 0.007) were not present in the orchard population, while one allele was unique to the orchard. The %P increased to 70.6% in the seedlot, but dropped to the natural populations level (64.7%) in the plantation. The observed increase in %P was a result of pollen contamination in the orchard. It is suspected that the reduction in the plantation was caused by an unintentional selection in the nursery. Simulated roguing in the orchard did not drastically reduce He even if up to 50% of the orchard’s clones were rogued. However, roguing was associated with a reduction in the average number of alleles per locus (i.e., sampling effect).
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Alden J, Loopstra C (1987) Genetic diversity and population structure of Picea glauca on an altitudinal gradient in interior Alaska. Can J for Res 17:1519–1526
Anonymous (1976) Twentieth anual report on cooperative tree improvement and hardwood research program. North Carolina State University. Raleigh, North Carolina
Bergmann F, Ruetz W (1991) Isozyme genetic variation and heterozygosity in random tree samples and selected orchard clones from the same Norway spruce populations. For Ecol Manag 46:39–47
Chaisurisri K, El-Kassaby YA (1994) Genetic diversity in a seed production population vs natural populations of Sitka spruce. Biodiv Consver 3:512–523
Cheliak WM, Pitel JA (1984) Genetic control of allozyme variants in mature tissues of white spruce trees. J Hered 75:34–40
Cheliak WM, Pitel JA, Murray G (1985) Population structure and mating system of white spruce. Can J For Res 15:301–308
Cheliak WM, Murray G, Pitel JA (1988) Genetic effects of phenotypic selection in white spruce. For Ecol Manag 24:139–149
Denti D, Schoen DJ (1988) Self-fertilization rates in white spruce: effects of pollen and seed production. J Hered 79:284–288
El-Kassaby YA (1989) Genetics of seed orchards: expectations and realities. In: Proc 20th South For Tree Improv Conf, Charleston, South Carolina
El-Kassaby YA (1991) Genetic variation within among conifer populations: review and evaluation of methods. In: Hattemer HH, Fineschi S, Cannata F, Malvoti ME (eds) Biochemical markers in population genetics of forest trees. SPB Academic Publishing bv, The Hague, pp 59–74
El-Kassaby YA (1992) Domestication and genetic diversity-should we be concerned?. For Chron 68:687–700
El-Kassaby YA (1995) Evaluation of the tree-improvement delivery system: factors affecting genetic potential. Tree Physiol 15: 545–550
El-Kassaby YA, Askew GR (1991) The relation between reproductive phenology and output in determining the gametic pool profile in a Douglas-fir seed orchard. For Sci 37:827–835
El-Kassaby YA, Namkoong G (1995) Genetic deversity of forest tree plantations: consequences of domestication, In: Consequences of changes in biodiversity. IUFRO World Congress, Tampere, Finland, Vol 2, pp 218–228
El-Kassaby YA, Ritland K (1996) Impact of selection and breeding on the genetic diversity in Douglas-fir. Biodiv Consver 5:795–813
El-Kassaby YA Thomson AJ (1996) Parental rank changes associated with seed biology and nursery practices in Douglas-fir. For Sci 42:228–235
El-Kassaby YA, Davidson R, Webber JW (1986) Genetics of seed orchards: a Douglas-fir case study. In: Hatcher AV, Weir RJ (eds) Proc IUFRO Work Parties, Williamsburg, Virginia, USA, pp 440–450
El-Kassaby YA, Sigurgeirsson A, Szmidt AE (1988) The use of restriction analysis of chloroplast DNA in classifying hybrid spruce seedlots. In: Hallgren JE (eds) Proc Frans Kempe Symp Molecular Genetics of Forest Trees, Swedish Univ Agric Sci, Umea, Sweden Rep 8:67–88
El-Kassaby YA, Russell J, Ritland K (1994) Mixed mating in an experimental population of western red cedar, Thuja plicata. J Hered 85:227–231
Ellstrand NC (1992) Gene flow among seed plant populations. New For 6:241–256
Francis CA (1981) Development of plant genotypes for multiple cropping systems. In: Frey KJ (ed) Plant breeding II. The Iowa State University Press, Ames, pp 179–231
Hamrick JL, Godt MJW (1989) Allozyme diversity in plant species. In: Urbanska K (ed) Differentiation patterns in higher plants. Academic Press, New York, pp 53–67
Innes DJ, Ringius GG (1990) Mating system and genetic structure of two populations of white spruce (Picea glauca) in eastern Newfoundland. Can J Bot 68:1661–1666
King JN, Dancik BP (1983) Inheritence and linkage of isozymes in white spruce (Picea glauca). Can J Genet Cytol 25:430–436
King JN, Dancik BP, Dhir NK (1984) Genetic structure and mating system of white spruce (Picea glauca) in a seed production area. Can J For Res 14:639–643
Knowles P (1985) Comparison of isozyme variation among natural stands and plantations: jack pine and black spruce. Can J For Res 15:902–908
Ledig FT (1986) Heterozygosity, heterosis, and fitness in outcrossing plants. In: Soule ME (ed) Conservation biology: the science of scarcity and diversity. Sinauer Assoc, Sunderland, Massachusetts, pp 77–104
Lewis PO, Whitkus R (1989) GENESTAT for microcomputers. Am Soc Plant Taxon Newslett 2:15–16
Lindgren D, Gregorious H (1976) Inbreeding and coancestry. In: Proc IUFRO Joint Mtg Advanced Genset Breed, Bordeaux, France, pp 49–71
Nei M (1973) Analysis of gene diversity in subdivided populations. Proc Natl Acad Sci USA 70:3321–3323
Nei M, Sykudo K (1958) The estimation of outcrossing in natural populations. Jap J Genet 33:46–51
Nei M, Maruyama T, Chakraborty R (1975) The bottleneck effect and genetic variability in populations. Evolution 29:1–10
Owens JN, Molder M (1979) Sexual reproduction of white spruce (Picea glauca). Can J Bot 57:152–169
Savolainen O, Karkkainen K (1992) Effect of forest management on gene pools. New For 6:329–345
Savolainen O, Yazdani R (1992) Genetic comparison of natural and artificial populations of Pinus sylvestris. In: Müller-Starck G, Ziehe M (eds) Genetic variation in european populations of forest trees. Sauerländer’s Verlag, Frankfurt am Main, pp 228–234
Schoen DJ, Stewart SC (1986) Variation in male reproductive investment and male reproductive success in white spruce. Evolution 40:1109–1120
Schoen DJ, Stewart SC (1987) Variation in male fertilities and pairwise mating probabilities in Picea glauca. Genetics 116: 141–152
Schoen DJ, Denti D, Stewart SC (1986) Strobilus production in a clonal white spruce seed orchard: evidence for unbalanced mating. Silvae Genet 35:201–205
Shea KL (1987) Effects of population structure and cone production on outcrossing rates in Englemann spruce and subalpine fir. Evolution 41:124–136
Slatkin M, Barton NH (1989) A comparison of the three indirect methods for estimating average levels of gene flow. Evolution 43: 1349–1368
Sneath PHA, Sokal RR (1973) Numerical taxonomy. W.H. Freeman, San Fransisco, USA
Stewart SC, Schoen DJ (1986) Segregation at enzyme loci in megagametophyte of white spruce, Picea glauca Can J Genet Cytol 28: 149–153
Swofford DL, Selander RB (1981) BIOSYS-I: A FORTAN program for the comprehensive analysis of electrophoretic data in population genetics and systematics. J Hered 72:281–283
Tremblay M, Simon JP (1989) Genetic structure of mariginal populations of white spruce (Picea glauca) at its northern limit of distribution in Nouveau-Québec. Can J For Res 19:1371–1379
Williams CG, Hamrick JL, Lewis PO (1995) Multiple-population versus hierarchical conifer breeding programs: a comparison of genetic diversity levels. Theor Appl Genet 90:584–594
Wright S (1965) The interpretation of population structure by F- statistics with special regard to systems of mating. Evolution 19: 355–420
Author information
Authors and Affiliations
Additional information
Communicated by P. M. A. Tigerstedt
Rights and permissions
About this article
Cite this article
Stoehr, M.U., El-Kassaby, Y.A. Levels of genetic diversity at different stages of the domestication cycle of interior spruce in British Columbia. Theoret. Appl. Genetics 94, 83–90 (1997). https://doi.org/10.1007/s001220050385
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s001220050385