Microsatellite Markers of Willow Species and Characterization of 11 Polymorphic Microsatellites for Salix eriocephala (Salicaceae), a Potential Native Species for Biomass Production in Canada

Biomass produced from dedicated plantations constitutes a source of renewable energy and is expected to play an important role in several countries in the coming decades. The cultivation of woody crops such as willows therefore raises several environmental issues. In North America, several native willows are potentially interesting for biomass producers. Willow trees are diverse but few species used for environmental applications have been the object of molecular genetic studies. Based on the sequenced poplar genome, 24 microsatellite markers were assayed on five native North American willow species: Salix amygdaloides, S. discolor, S. eriocephala, S. interior and S. nigra. Polymorphic microsatellite markers were used to characterize the allele data on the shrub Salix eriocephala, a North American species with economic potential. Eleven markers amplified and confirmed the potential of this species. Analysis of samples from six populations in eastern Canada showed that all markers were variable as well as polymorphic in at least one population. The number of alleles per locus ranged from 1 to 9 (mean 2.95) and showed that these microsatellite markers can be used to assess genetic diversity of North American willow species

Microsatellite Markers of Willow Species and Characterization of 11 Polymorphic Microsatellites for Salix eriocephala (Salicaceae), a Potential Native Species for Biomass Production in Canada

Biomass produced from dedicated plantations constitutes a source of renewable energy and is expected to play an important role in several countries in the coming decades. The cultivation of woody crops such as willows therefore raises several environmental issues. In North America, several native willows are potentially interesting for biomass producers. Willow trees are diverse but few species used for environmental applications have been the object of molecular genetic studies. Based on the sequenced poplar genome, 24 microsatellite markers were assayed on five native North American willow species: Salix amygdaloides, S. discolor, S. eriocephala, S. interior and S. nigra. Polymorphic microsatellite markers were used to characterize the allele data on the shrub Salix eriocephala, a North American species with economic potential. Eleven markers amplified and confirmed the potential of this species. Analysis of samples from six populations in eastern Canada showed that all markers were variable as well as polymorphic in at least one population. The number of alleles per locus ranged from 1 to 9 (mean 2.95) and showed that these microsatellite markers can be used to assess genetic diversity of North American willow species

Treatment of Landfill Leachate by Short-Rotation Willow Coppice Plantations in a Large-Scale Experiment in Eastern Canada

The treatment of leachate by vegetative filters composed of short-rotation willow coppice (SRWC) has been shown to be a cost-effective alternative to conventional and costly methods. However, few studies have considered the treatment capability of willow filters at a scale large enough to meet the industrial requirements of private landfill owners in North America. We report here on a field trial (0.5 ha) in which a willow plantation was irrigated with groundwater (D0) or aged leachate at two different loadings (D1 and D2, which was twice that of D1). Additionally, half of the D2-irrigated plots were amended with phosphorus (D2P). The system, which operated for 131 days, was highly efficient, causing the chemical oxygen demand concentration to drop significantly with the total removal of ammonia (seasonal average removal by a concentration of 99–100%). D2P efficacy was higher than that of D2, indicating that P increased the performance of the system. It also increased the willow biomass 2.5-fold compared to water irrigation. Leaf tissue analysis revealed significant differences in the concentrations of total nitrogen, boron, and zinc, according to the treatment applied, suggesting that the absorption capacity of willows was modified with leachate irrigation. These results indicate that the willow plantation can be effective for the treatment of landfill leachate in respect of environmental requirements

Correction: Phylogenetic Relationships of American Willows (<i>Salix</i> L., Salicaceae)

<p>Correction: Phylogenetic Relationships of American Willows (<i>Salix</i> L., Salicaceae)</p

Phylogenetic Relationships of American Willows (<i>Salix</i> L., Salicaceae)

<div><p><i>Salix</i> L. is the largest genus in the family Salicaceae (450 species). Several classifications have been published, but taxonomic subdivision has been under continuous revision. Our goal is to establish the phylogenetic structure of the genus using molecular data on all American willows, using three DNA markers. This complete phylogeny of American willows allows us to propose a biogeographic framework for the evolution of the genus. Material was obtained for the 122 native and introduced willow species of America. Sequences were obtained from the ITS (ribosomal nuclear DNA) and two plastid regions, <i>matK</i> and <i>rbcL</i>. Phylogenetic analyses (parsimony, maximum likelihood, Bayesian inference) were performed on the data. Geographic distribution was mapped onto the tree. The species tree provides strong support for a division of the genus into two subgenera, <i>Salix</i> and <i>Vetrix</i>. Subgenus <i>Salix</i> comprises temperate species from the Americas and Asia, and their disjunction may result from Tertiary events. Subgenus <i>Vetrix</i> is composed of boreo-arctic species of the Northern Hemisphere and their radiation may coincide with the Quaternary glaciations. Sixteen species have ambiguous positions; genetic diversity is lower in subg. <i>Vetrix</i>. A molecular phylogeny of all species of American willows has been inferred. It needs to be tested and further resolved using other molecular data. Nonetheless, the genus clearly has two clades that have distinct biogeographic patterns.</p></div

BEAST gene tree of <i>matK</i> and <i>rbcL</i>.

<p>Branch support is Bayesian posterior probabilities and ML bootstrap values; subgenera are identified using colors; <i>Idesia</i> and <i>Populus</i> are outgroups.</p

BEAST gene tree of <i>ITS</i>.

<p>Branch support is Bayesian posterior probabilities and ML bootstrap values; subgenera are identified using colors; <i>Idesia</i> and <i>Populus</i> are outgroups.</p

BEAST species tree generated with <i>ITS</i>, <i>matK</i> and <i>rbcL</i>.

<p>Branch support is Bayesian posterior probabilities and ML bootstrap values; subgenera are identified using colors; native areas (Argus 2007) are indicated by colored circles; <i>Idesia</i> and <i>Populus</i> are outgroups.</p