Population variation in North American Menziesia (Ericaceae)

• Main Author: Wells, Thomas Cameron
• Format: Others
• Language: English
• Published: 2008
• Online Access: http://hdl.handle.net/2429/3012

Menziesip, a widespread genus of shrubs, occurs in temperate montane regions of North Zmerica (2 species) and Japan (8 species). Although this disjunct distribution is shared by numerous vascular plant genera, few have been examined biosystematically within and among the floristic regions. In western North rnerica, N. ferrupinea is a highly variable species and apparently is related closely to Appalachian N. pilosa, based on flavonoid analyses. In this study, univariate and multivariate analyses of 22 morphological descriptors revealed discontinuous and clinal variation along west-east and north-south gradients in N. ferrupinea, allowing recognition of two phases. Using the same procedures, N. pilosa proved to be comparatively uniform. Variation was partitioned largely within rather than among populations, with morphological patterns spatially correlated on a regional scale. Past and present migrational events and, to a lesser degree, ecological variables have contributed to clinal development. Analyses also were made using starch gel electrophoresis with 13 enzyme systems coding for 19 loci. Isozyme variation resided predominantly within rather than among populations, with lower than expected total genetic diversity. Levels of allozyme variation within populations were comparable to other xenogamous, entomophilous species.[more abstract] === Science, Faculty of === Botany, Department of === Graduate