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The breakdown of host resistance to plant pathogens is of critical concern in agriculture, forestry, and the management of natural systems. Evolution of the fungal poplar rust pathogen Melampsora larici-populina has been shown to have been dramatically influenced by the deployment of resistance genes in commercial poplar (Populus spp.) plantations, with pathogen populations inundated by virulent genotypes (Xhaard et al. 2011).
Provenance tests of 49 populations of whitebark pine (Pinus albicaulis) revealed moderate genetic differentiation for growth potential (growth under conditions approaching physiological optimum). Moderate genetic differentiation was also detected for survival after more than 10 years under warm-dry climate in the field but not for unconditional expected height, which was considered the best available predictor of fitness.
During the naturalization process of white pine blister rust (WPBR, caused by Cronartium ribicola), susceptible pine genotypes will be selected against, along with any traits that are associated with those genotypes, potentially causing a shift in the suite of traits in the post-selection population compared to the native population.
The German Barcode of Life (GBOL) project is a large-scale DNA barcoding initiative to assess the biodiversity of animals, fungi, and plants of Germany. Here we introduce the subproject focusing on rust fungi (Pucciniales, Basidiomycota). This is the only group of fungi represented in the initial 3.5-year phase of the project.
Controlled inoculations of whitebark pine (Pinus albicaulis) families in British Columbia (BC), Canada, took place in 2013 and 2014 at the Kalamalka Forestry Centre in Vernon. This effort has focused on 40 families from the Kootenay region with results (identification of disease-resistant families) expected over the next 5 years. Meanwhile, demand continues for further screening of whitebark pine from other regions in Canada.
Whitebark pine (Pinus albicaulis) is very susceptible to white pine blister rust, caused by the fungal pathogen Cronartium ribicola. Operational programs to develop resistant populations of whitebark pine are underway. These programs rely on artificial inoculation of young seedlings and can evaluate hundreds of parent trees using seedling progeny in a relatively short time.
Climate-based predictions of species distributions provide information for understanding impacts of climate change. However, species distribution models do not include land management zones as input. Improving understanding of geographic shifts will require consideration of management zones where certain activities could facilitate or impede responses to climate change.
Limber pine (Pinus flexilis) and Rocky Mountain bristlecone pine (Pinus aristata) are important components of forest ecosystems in the southern Rocky Mountains, United States. Both species are susceptible to white pine blister rust caused by the fungal pathogen Cronartium ribicola. However, very little is known about the relative resistance of the two species.
Cronartium flaccidum is a serious pathogen of twoneedle pines, especially of Pinus sylvestris, in northern Fennoscandia (Samils et al. 2010). The rust spreads via a number of alternate hosts in natural forests and gardens, among which species in genera Melampyrum, Pedicularis, Vincetoxicum, and Paeonia are the most important known ones (Gäumann 1959; Kaitera et al. 1999).
The recent completion of genome sequencing for some rust fungi has contributed to suggest a link between biotrophic specialization and genome size expansion. The measurement of genome sizes for a selection of rust fungi has revealed some of the largest genomes among fungi, with nine rust species with haploid genomes between 300 and 780 Mbp. In particular, Uromyces appendiculatus, Phakopsora pachyrhizi, U.