Sedley Josserand

Evolutionary history of two endemic Appalachian conifers revealed using microsatellite markers

Fraser fir (Abies fraseri [Pursh] Poir.) and intermediate fir (Abies balsamea [L.] Mill. var. phanerolepis Fern.) exist in small populations in the Appalachian highlands of the southeastern United States. We used ten nuclear microsatellite markers to quantify genetic variation within Fraser fir and intermediate fir, and to examine their evolutionary relationships with the widespread balsam fir (Abies balsamea [L.] Mill.). We found little genetic differentiation among these taxa, suggesting that Fraser fir might best be classified as a variety of balsam fir. The results further appear to reject the hypothesis that intermediate fir was of hybrid origin between two comparatively distantly related species. Low levels of genetic diversity suggest that intermediate fir and Fraser fir have undergone at least some genetic degradation since post-Pleistocene isolation. The results may prove important for in situ and ex situ gene conservation efforts for Fraser fir and intermediate fir, which are imperiled by an exotic insect and by global climate change.

Microsatellite markers for eastern hemlock (Tsuga canadensis)

We describe polymerase chain reaction primer pairs and reaction conditions for amplification of 15 microsatellite loci from eastern hemlock (Tsuga canadensis). The primers were tested on 23 individuals from a natural population in southwestern North Carolina, USA. These primers yielded an average of 5.9 alleles per locus (range of 2–14), an average observed heterozygosity of 0.45 (range 0.14–0.73), and an average polymorphic information content of 0.54 (range 0.28–0.86). In addition, eight of the primer pairs were found to amplify microsatellite loci in one or more additional species of Tsuga.

Genetic Diversity and Population Structure of Shortleaf Pine (Pinus echinata) in the Missouri Ozarks

Abstract Shortleaf pine (Pinus echinata), Missouris only native pine species, experienced intense logging during the post-Civil War Ozark lumber boom. Although recent restoration efforts have occurred primarily on federal and state land, efforts are being made to incorporate shortleaf management strategies on private land through the distribution of 1 y old bare-root seedlings grown from seeds at the George O. White nursery in Licking, Mo. In this study we examined the genetic structure of Missouris historic shortleaf pines to determine if geographic compartmentalization of seed stock was necessary. Using twelve polymorphic microsatellite loci, we genotyped historic shortleaf pine wood core samples from eight counties in the Missouri Ozarks and needles from seedlings provided by the George O. White nursery. Missouris historic shortleaf pine populations exhibited high heterozygosity and no observable pattern of genetic structure between individuals of varying geographic location, diameter at breast height (DBH), or altitude. However, private alleles found in all but one of the historic populations suggest the presence of a form of genetic diversity in Missouris shortleaf pine populations that is not present in the George O. White nursery stock. To maintain high levels of genetic diversity over the long term and prevent overrepresentation of alleles from nursery stock in reintroduced shortleaf populations, managers should consider increasing the number of individuals used as seed sources for seedling propagation.