Allozyme Diversity in Natural Populations of Viola palmensis Webb & Berth. (Violaceae) from La Palma (Canary Islands): Implications for Conservation Genetics

Abstract

Genetic diversity was measured by allozyme electrophoresis in eight natural populations of the threatened Canarian endemic Viola palmensis Webb & Berth. (Violaceae). Nineteen alleles corresponding to 11 gene loci were detected. High levels of genetic diversity were found, ranging from 36.3 to 45.4 % for the percentage of polymorphic loci (P), from 1.45 to 1.60 for the average number of alleles per locus (A) and from 0.128 to 0.200 for the expected heterozygosity (H(e)). Between 85.5 and 96.6 % of genetic variability was apportioned within populations. As a whole, populations were not at Hardy-Weinberg equilibrium, with a deficit of heterozygous individuals attributable to the existence of genetic structuring in the populations analysed. The levels of interpopulation genetic differentiation were low (mean F(ST) = 0.100), while genetic identity pair-wise comparisons were high (mean I = 0.973) suggesting considerable levels of gene flow among populations. No relationship was detected between genetic differentiation and geographical distances between populations. An outcrossing insect-mediated breeding system might contribute to pollen dispersion of this species. For conservation genetics we suggest in situ preservation areas are defined that are free of disturbance and that include populations with the highest genetic diversity.

Allozyme variation and structure of the Canarian endemic palm tree Phoenix canariensis (Arecaceae): implications for conservation

“…Thus, although Eguiarte et al (1992) found a similar value to P. canariensis' in the rain forest palm Astrocaryum mexicanum (He ¼ 0.153), lower values were described in Carpentaria acuminata, (He ¼ 0.143), Ptychosperma bleeseri (He ¼ 0.006) and Pinanga tenella (He ¼ 0.133) (Shapcott, 1998a(Shapcott, , b, 1999 and in Washingtonia filifera (He ¼ 0.008) (McClenaghand and Beauchamp, 1986). This result agrees with other studies that show higher genetic diversity levels in Canarian endemic plants than in those distributed in other oceanic islands (Francisco-Ortega et al, 2000;Batista et al, 2001;Batista and Sosa, 2002;Bouza et al, 2002). On the whole, the three groups of populations exhibited higher genetic variability values than species with similar life history traits (monocotyledons, endemics and species with sexual reproduction).…”

Genetic diversity of the endangered coastal violet Viola grayi Franchet et Savatier (Violaceae) and its genetic relationship to the species in subsection Rostratae

“…This is in very clear contrast to the previously reported inbreeding coefficients on other Viola species. Batista and Sosa (2002) reported F IS = 0.375 for V. palmensis based on isozyme analysis. Culley and Wolfe (2001) reported F IS = -0.09 for V. pubescens based on isozyme analysis.…”

Population genetics of Howellia aquatilis (Campanulaceae) in disjunct locations throughout the Pacific Northwest

“…The amount of genetic variation and differentiation among populations can be influential in habitat management and species preservation, especially in the case of rare and endangered species Hamrick 1993, 2001;Batista and Sosa 2002). An AFLP study on the Federally endangered Kanab ambersnail (Oxyloma haydeni kanabensis) provided resource managers with the genetic data to establish that the two surviving populations are genetically distinct and should be protected (Miller et al 2000).…”