Morphology of uredinia and urediniospores of the fungus Melampsora larici-epitea Kleb. a damaging pathogen of common osier (Salix viminalis L.) in Poland

Rust (Melampsora spp.) is a damaging disease of willows (Salix spp.), including common osier (S. viminalis L.). So far, the pathogens of this species found in Europe were identified as M. larici-epitea Kleb. or M. ribesii-viminalis Kleb. Moreover, a stem infecting form (SIF), deprived of a sexual stage in its life cycle was reported. The aim of this study was to find out which species of the rust fungi cause disease symptoms on common osier in Poland. The isolates from common osier were compared to the ones originating from its putative hybrids with trembling aspen (Populus tremula L.) and Simon's poplar (P. simonii Carr.). Fungal isolates were obtained in 2008-2010 from 15 different genotypes of willows, including seven varieties of common osier (4 Swedish and 3 Polish), two landraces of common osier and six putative hybrids with poplars. Fungal isolates originated from three experiment sites, including west (Wielkopolska and Lubuskie) and north-east (Warmia) regions of Poland. To ensure the genetic uniformity, the isolates were derived from single uredinia, obtained from natural infection conditions. In all collected samples the position of uredinia was always hypophyllous. The diameter of uredinia was measured by Sigma Scan Pro software, after inoculation of four standard genotypes, including two common osier and two willow hybrids. The studies proved that the main cause of common osier rust is Melampsora larici-epitea f. typica. All studied isolates, including the ones obtained on putative hybrids, were very similar according to the size of uredinia and the size and morphology of urediniospores. The average size of a uredinium was 1.1 mm diameter and slightly differed between the isolates (from 0.9 to 1.3 mm), depending on willow genotype, the quality of plant material used for artificial inoculations and infection conditions. The average size of a typical urediniospore was 12.4 x 10.5 µm, but the sizes varied from 9.8 to 13.2 µm. Urediniospores from common osier were slightly bigger and more oval (12.5 x 10.4 µm) as compared to spores from the putative hybrids Salix x Populus (12.3 x 10.6 µm), but the differences were statistically insignificant. The spores were ovoid, globoid or angular, evenly echinulated. The size of uredinia, as well as the size and morphology of urediniospores were in full agreement with literature data for M. larici-epitea f. typica

Establishment, growth and yield potential of the perennial grass Miscanthus x giganteus on degraded coal mine soils

BBS/E/W/10963A01Miscanthus x giganteus is a giant C4 grass native to Asia. Unlike most C4 species, it is relatively cold tolerant due to adaptations across a wide range of altitudes. These grasses are characterized by high productivity and low input requirements, making them excellent candidates for bioenergy feedstock production. The aim of this study was to investigate the potential for growing Miscanthus on extremely marginal soils, degraded by open lignite (brown coal) mining. Field experiments were established within three blocks situated on waste heaps originating from the lignite mine. Analyses were conducted over the first 3 years following Miscanthus cultivation, focusing on the effect of organic and mineral fertilization on crop growth, development and yield in this extreme environment. The following levels of fertilization were implemented between the blocks: the control plot with no fertilization (D0), a plot with sewage sludge (D1), a plot with an identical amount of sewage sludge plus one dose of mineral fertilizer (D2) and a plot with an identical amount of sewage sludge plus a double dose of mineral fertilizer (D3). Crop development and characteristics (plant height, tillering, and biomass yield [dry matter]) were measured throughout the study period and analyzed using Analysis of Variance (ANOVA). Significant differences were apparent between plant development and 3rd year biomass production over the course of the study (0.964 kg plant-1 for DO compared to 1.503 kg plant-1 for D1). Soil analyses conducted over the course of the experiment showed that organic carbon levels within the soil increased significantly following the cultivation of Miscanthus, and overall, pH decreased. With the exception of iron, macronutrient concentrations remained stable throughout. The promising yields and positive effects of Miscanthus on the degraded soil suggests that long term plantations on land otherwise unsuitable for agriculture may prove to be of great environmental and economic significancepublishersversionPeer reviewe

Genome biology of the paleotetraploid perennial biomass crop Miscanthus

Miscanthus is a perennial wild grass that is of global importance for paper production, roofing, horticultural plantings, and an emerging highly productive temperate biomass crop. We report a chromosome-scale assembly of the paleotetraploid M. sinensis genome, providing a resource for Miscanthus that links its chromosomes to the related diploid Sorghum and complex polyploid sugarcanes. The asymmetric distribution of transposons across the two homoeologous subgenomes proves Miscanthus paleo-allotetraploidy and identifies several balanced reciprocal homoeologous exchanges. Analysis of M. sinensis and M. sacchariflorus populations demonstrates extensive interspecific admixture and hybridization, and documents the origin of the highly productive triploid bioenergy crop M. x giganteus. Transcriptional profiling of leaves, stem, and rhizomes over growing seasons provides insight into rhizome development and nutrient recycling, processes critical for sustainable biomass accumulation in a perennial temperate grass. The Miscanthus genome expands the power of comparative genomics to understand traits of importance to Andropogoneae grasses

Genome biology of the paleotetraploid perennial biomass crop Miscanthus.

Miscanthus is a perennial wild grass that is of global importance for paper production, roofing, horticultural plantings, and an emerging highly productive temperate biomass crop. We report a chromosome-scale assembly of the paleotetraploid M. sinensis genome, providing a resource for Miscanthus that links its chromosomes to the related diploid Sorghum and complex polyploid sugarcanes. The asymmetric distribution of transposons across the two homoeologous subgenomes proves Miscanthus paleo-allotetraploidy and identifies several balanced reciprocal homoeologous exchanges. Analysis of M. sinensis and M. sacchariflorus populations demonstrates extensive interspecific admixture and hybridization, and documents the origin of the highly productive triploid bioenergy crop M. × giganteus. Transcriptional profiling of leaves, stem, and rhizomes over growing seasons provides insight into rhizome development and nutrient recycling, processes critical for sustainable biomass accumulation in a perennial temperate grass. The Miscanthus genome expands the power of comparative genomics to understand traits of importance to Andropogoneae grasses