DIFFERENCES AMONG APPRAISERS IN THE NEW YORK TYPE APPRAISAL PROGRAM

The purpose of the New York type appraisal program is to attempt to rate type traits objectively. Approximately 34 traits are included, of which 25 are rated by the appraiser and 9 by the herd manager. This paper reports differences among 18 appraisers, including S professional judges, 7 New York Artificial Breeders\u27 Cooperative fieldmen, and 3 other sire selection personnel all of whom rated 38 cows in a single herd. There were statistically significant differences (P ≤ .05) among appraisers for all traits. Average scores of the professionals were different from those of the fieldmen for all except six traits. Differences among the professionals were also large, as were the differences among the fieldmen. The results suggest that the fieldmen as a group appraised with as much consistency as the group of professional judges

DIFFERENCES AMONG APPRAISERS IN THE NEW YORK TYPE APPRAISAL PROGRAM

The purpose of the New York type appraisal program is to attempt to rate type traits objectively. Approximately 34 traits are included, of which 25 are rated by the appraiser and 9 by the herd manager. This paper reports differences among 18 appraisers, including S professional judges, 7 New York Artificial Breeders\u27 Cooperative fieldmen, and 3 other sire selection personnel all of whom rated 38 cows in a single herd. There were statistically significant differences (P ≤ .05) among appraisers for all traits. Average scores of the professionals were different from those of the fieldmen for all except six traits. Differences among the professionals were also large, as were the differences among the fieldmen. The results suggest that the fieldmen as a group appraised with as much consistency as the group of professional judges

Cell wall acetylation in hybrid aspen affects field performance, foliar phenolic composition and resistance to biological stress factors in a construct-dependent fashion

The production of biofuels and “green” chemicals from the lignocellulose of fast-growing hardwood species is hampered by extensive acetylation of xylan. Different strategies have been implemented to reduce xylan acetylation, resulting in transgenic plants that show good growth in the greenhouse, improved saccharification and fermentation, but the field performance of such plants has not yet been reported. The aim of this study was to evaluate the impact of reduced acetylation on field productivity and identify the best strategies for decreasing acetylation. Growth and biological stress data were evaluated for 18 hybrid aspen lines with 10–20% reductions in the cell wall acetyl content from a five year field experiment in Southern Sweden. The reduction in acetyl content was achieved either by suppressing the process of acetylation in the Golgi by reducing expression of REDUCED WALL ACETYLATION(RWA) genes, or by post-syntheticacetyl removal by fungal acetyl xylan esterases (AXEs) from two different families, CE1and CE5, targeting them to cell walls. Transgene expression was regulated by either a constitutive promoter (35S)or a wood-specific promoter (WP). For the majority of transgenic lines, growth was either similar to that in WT and transgenic control (WP:GUS)plants, or slightly reduced. The slight reduction was observed in the AXE-expressing lines regulated by the 35S promoter, not those with the WPpromoter which limits expression to cells developing secondary walls. Expressing AXEs regulated by the 35S promoter resulted in increased foliar arthropod chewing, and altered condensed tannins and salicinoid phenolic glucosides (SPGs) profiles. Greater growth inhibition was observed in the case of CE5 than with CE1 AXE, and it was associated with increased foliar necrosis and distinct SPG profiles, suggesting that CE5 AXE could be recognized by the pathogen-associated molecular pattern system. For each of three different constructs, there was a line with dwarfism and growth abnormalities, suggesting random genetic/epigenetic changes. This high frequency of dwarfism (17%)is suggestive of a link between acetyl metabolism and chromatin function. These data represent the first evaluation of acetyl-reduced plants from the field, indicating some possible pitfalls, and identifying the best strategies, when developing highly productive acetyl-reduced feedstocks

UHPLC-ESI/TOFMS Determination of Salicylate-like Phenolic Gycosides in Populus tremula Leaves

Associations of salicylate-like phenolic glycosides (PGs) with biological activity have been reported in Salix and Populus trees, but only for a few compounds, and in relation to a limited number of herbivores. By considering the full diversity of PGs, we may improve our ability to recognize genotypes or chemotype groups and enhance our understanding of their ecological function. Here, we present a fast and efficient general method for salicylate determination in leaves of Eurasian aspen that uses ultra-high performance liquid chromatography-electrospray ionization/time-of-flight mass spectrometry (UHPLC-ESI/TOFMS). The time required for the liquid chromatography separations was 13.5 min per sample, compared to around 60 min per sample for most HPLC protocols. In leaf samples from identical P. tremula genotypes with diverse propagation and treatment histories, we identified nine PGs. We found the compound-specific mass chromatograms to be more informative than the UV-visible chromatograms for compound identification and when quantitating samples with large variability in PG content. Signature compounds previously reported for P. tremoloides (tremulacin, tremuloidin, salicin, and salicortin) always were present, and five PGs (2'-O-cinnamoyl-salicortin, 2'-O-acetyl-salicortin, 2'-O-acetyl-salicin, acetyl-tremulacin, and salicyloyl-salicin) were detected for the first time in P. tremula. By using information about the formic acid adduct that appeared for PGs in the LTQ-Orbitrap MS environment, novel compounds like acetyl-tremulacin could be tentatively identified without the use of standards. The novel PGs were consistently either present in genotypes regardless of propagation and damage treatment or were not detectable. In some genotypes, concentrations of 2'-O-acetyl-salicortin and 2'-O-cinnamoyl-salicortin were similar to levels of biologically active PGs in other Salicaceous trees. Our study suggests that we may expect a wide variation in PG content in aspen populations which is of interest both for studies of interactions with herbivores and for mapping population structure

A global view of aspen : Conservation science for widespread keystone systems

Across the northern hemisphere, six species of aspen (Populus spp.) play a disproportionately important role in promoting biodiversity, sequestering carbon, limiting forest disturbances, and providing other ecosystem services. These species are illustrative of efforts to move beyond single-species conservation because they facilitate hundreds of plants and animals worldwide. This review is intended to place aspen in a global conservation context by focusing on the many scientific advances taking place in such biologically diverse systems. In this manner, aspen may serve as a model for other widespread keystone systems where science-based practice may have world implications for biodiversity conservation. In many regions, aspen can maintain canopy dominance for decades to centuries as the sole major broadleaf trees in forested landscapes otherwise dominated by conifers. Aspen ecosystems are valued for many reasons, but here we highlight their potential as key contributors to regional and global biodiversity. We present global trends in research priorities, strengths, and weaknesses based on, 1) a qualitative survey, 2) a systematic literature analysis, and 3) regional syntheses of leading research topics. These regional syntheses explore important aspen uses, threats, and research priorities with the ultimate intent of research sharing focused on sound conservation practice. In all regions, we found that aspen enhance biodiversity, facilitate rapid (re)colonization in natural and damaged settings (e.g., abandoned mines), and provide adaptability in changing environments. Common threats to aspen ecosystems in many, but not all, regions include effects of herbivory, land clearing, logging practices favoring conifer species, and projected climate warming. We also highlight regional research gaps that emerged from the three survey approaches above. We believe multi-scale research is needed that examines disturbance processes in the context of dynamic climates where ecological, physiological, and genetic variability will ultimately determine widespread aspen sustainability. Based on this global review of aspen research, we argue for the advancement of the “mega-conservation” strategy, centered on the idea of sustaining a set of common keystone communities (aspen) that support wide arrays of obligate species. This approach contrasts with conventional preservation which focuses limited resources on individual species residing in narrow niches.Peer reviewe

Impact of xylan on field productivity and wood saccharification properties in aspen

Xylan that comprises roughly 25% of hardwood biomass is undesirable in biorefinery applications involving saccharification and fermentation. Efforts to reduce xylan levels have therefore been made in many species, usually resulting in improved saccharification. However, such modified plants have not yet been tested under field conditions. Here we evaluate the field performance of transgenic hybrid aspen lines with reduced xylan levels and assess their usefulness as short-rotation feedstocks for biorefineries. Three types of transgenic lines were tested in four-year field tests with RNAi constructs targeting either Populus GT43 clades B and C (GT43BC) corresponding to Arabidopsis clades IRX9 and IRX14, respectively, involved in xylan backbone biosynthesis, GATL1.1 corresponding to AtGALT1 involved in xylan reducing end sequence biosynthesis, or ASPR1 encoding an atypical aspartate protease. Their productivity, wood quality traits, and saccharification efficiency were analyzed. The only lines differing significantly from the wild type with respect to growth and biotic stress resistance were the ASPR1 lines, whose stems were roughly 10% shorter and narrower and leaves showed increased arthropod damage. GT43BC lines exhibited no growth advantage in the field despite their superior growth in greenhouse experiments. Wood from the ASPR1 and GT43BC lines had slightly reduced density due to thinner cell walls and, in the case of ASPR1, larger cell diameters. The xylan was less extractable by alkali but more hydrolysable by acid, had increased glucuronosylation, and its content was reduced in all three types of transgenic lines. The hemicellulose size distribution in the GALT1.1 and ASPR1 lines was skewed towards higher molecular mass compared to the wild type. These results provide experimental evidence that GATL1.1 functions in xylan biosynthesis and suggest that ASPR1 may regulate this process. In saccharification without pretreatment, lines of all three constructs provided 8-11% higher average glucose yields than wild-type plants. In saccharification with acid pretreatment, the GT43BC construct provided a 10% yield increase on average. The best transgenic lines of each construct are thus predicted to modestly outperform the wild type in terms of glucose yields per hectare. The field evaluation of transgenic xylan-reduced aspen represents an important step towards more productive feedstocks for biorefineries

Cadophora margaritata sp. nov. and other fungi associated with the longhorn beetles Anoplophora glabripennis and Saperda carcharias in Finland

Symbiosis with microbes is crucial for survival and development of wood-inhabiting longhorn beetles (Coleoptera: Cerambycidae). Thus, knowledge of the endemic fungal associates of insects would facilitate risk assessment in cases where a new invasive pest occupies the same ecological niche. However, the diversity of fungi associated with insects remains poorly understood. The aim of this study was to investigate fungi associated with the native large poplar longhorn beetle (Saperda carcharias) and the recently introduced Asian longhorn beetle (Anoplophora glabripennis) infesting hardwood trees in Finland. We studied the cultivable fungal associates obtained from Populus tremula colonised by S. carcharias, and Betula pendula and Salix caprea infested by A. glabripennis, and compared these to the samples collected from intact wood material. This study detected a number of plant pathogenic and saprotrophic fungi, and species with known potential for enzymatic degradation of wood components. Phylogenetic analyses of the most commonly encountered fungi isolated from the longhorn beetles revealed an association with fungi residing in the Cadophora-Mollisia species complex. A commonly encountered fungus was Cadophora spadicis, a recently described fungus associated with wood-decay. In addition, a novel species of Cadophora, for which the name Cadophora margaritata sp. nov. is provided, was isolated from the colonised wood.Peer reviewe