Seed gene flow and fine-scale structure in a Mediterranean pine (Pinus pinaster Ait.) using nuclear microsatellite markers

• Published in: Theoretical and applied genetics Vol. 104; no. 8; pp. 1290 - 1297
• Main Authors: GONZALEZ-MARTINEZ, S. C, GERBER, S, CERVERA, M. T, MARTINEZ-ZAPATER, J. M, GIL, L, ALIA, R
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.06.2002; Berlin Springer Nature B.V; Springer Verlag
• Subjects: Biological and medical sciences; Classical genetics, quantitative genetics, hybrids; Flowers & plants; Forest & brush fires; Fundamental and applied biological sciences. Psychology; Genetic aspects; Genetics; Genetics of eukaryotes. Biological and molecular evolution; Life Sciences; Paternity; Physiological aspects; Pine; Plant genetics; Plant populations; Plant reproduction; Population genetics; Pteridophyta, spermatophyta; Seeds; Vegetals; Iberian Peninsula; Europe; France; Spain; Madrid Spain; Pinus pinaster; Gene flow; Genetic marker; Repeated sequence; Microsatellite DNA; Gymnospermae; Softwood forest tree; Genetics; Coniferales; Spermatophyta; Molecular marker; GENETIQUE; PIN MARITIME
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/s00122-002-0894-4

The Mediterranean populations of maritime pine ( Pinus pinaster Ait.) are typically small and have a scattered distribution, being threatened by human activities and forest fires. In the framework of the genetic-resources conservation program of this species, a native multi-age stand located in a Mediterranean area (central Spain) was studied using three highly polymorphic nuclear microsatellites (SSRs). Spatial autocorrelation analysis was conducted using Moran's index in order to detect fine-scale structure in both natural regeneration and mature trees. The spatial pattern of seed flow based on dispersed progeny was studied using a highly reliable subset of parent-offspring matches obtained by means of parentage analysis and simulation-based calculation of statistical confidence. Maritime pine showed a fine-scale structure at the seedling stage. In natural regeneration, the autocorrelograms indicated a patch size of approximately 10 m. The fine-scale structure seems to be produced by a restricted seed gene flow. In fact, there was an excess of parent-offspring matches in a radius of 15 m from the parent trees. Pines with a heavy seed, such as P. pinaster, are expected to have a short dispersal distance, thus producing a fine-scale structure. However, the fine-scale structure did not persist in the mature trees. Within-population genetic structure in Mediterranean pines may be affected by a number of post-dispersal events (e.g. mortality due to the severity of the Mediterranean climate and animal-mediated secondary dispersal during the summer period). Thus, great alteration in the pattern produced by the initial seed rain and differences in genetic structure between tree cohorts are expected.