Contrasting coarse and fine scale genetic structure among isolated relic populations of Kmeria septentrionalis

• Published in: Genetica 2010-10, Vol.138 (9-10), p.939-944
• Main Authors: Zhao, Jian-Li, He, Tianhua, Li, Qiao-Ming
• Format: Article
• Language: English
• Subjects: AFLP; Amplified Fragment Length Polymorphism Analysis; Animal Genetics and Genomics; Biomedical and Life Sciences; China; Conservation; Conservation of Natural Resources; Economic importance; Economics; Evolutionary Biology; Gene Flow; Genetic diversity; Genetic structure; Genetic Variation; Genetics, Population; Genome, Plant; Human Genetics; isolation; Kmeria septentrionalis; Life Sciences; Magnoliaceae - genetics; Microbial Genetics and Genomics; Natural populations; Original Research; Plant Genetics and Genomics; Pollen; Sample Size; Seed Dispersal; Spatial autocorrelation analysis
• ISSN: 0016-6707; 1573-6857
• DOI: 10.1007/s10709-010-9475-7

Trees of the Magnoliaceae family are of scientific, cultural and socio-economic importance. Kmeria septentrionalis Dandy (Magnoliaceae) is a dioecious tree, found in small, isolated, relic populations in Southern China, and is subject to extensive protection due to its rarity and high economic values. To improve conservation outcomes and in particular, germplasm collection guidelines, information on spatial genetic structure of the species is required. In this study, we investigated the spatial genetic structure and genetic diversity of 161 individuals of K. septentrionalis collected from five natural populations using AFLP molecular markers. Within-population genetic variation was measured, with percentage of polymorphic bands (PPB) ranged from 63% to 87%, while H S (genetic diversity within population) varied from 0.185 to 0.244 with a mean of 0.215 ± 0.025. Significant genetic differentiations were revealed between pairwise populations, indicating each population existing as an independent evolutionarily significant unit. Mantel test results showed no pattern of isolation-by-distance among populations separated by large distance. Fine scale spatial patterns of genetic variation suggested significant effects of isolation-by-distance within population at distances of 22 m. The results of contrasting genetic structure at coarse and fine scale in K. septentrionalis may indicate restricted pollen flow and seed dispersal at fine scales, and separated evolution in isolated populations over long period of time at coarser scales. Finally, we make several suggestions for improved management practices that may assist in the conservation of this species.