Wood - Wikipedia
outer bark and phloem and their relationships to resistance against the emerald ash borer . pest from Asia that has killed millions of ash trees (Fraxinus spp.) . Percent carbon and nitrogen, pH and elemental composition. distribution of the inorganic constituents in trees is required to estimate the .. Relationship between bark concentration (%) and bark ash content (%) III. Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other . No definite relation exists between the annual rings of growth and the amount of . wood such as one sees so prominently in oak and ash, for example. . The chemical composition of wood varies from species to species, but is.
Larvae of EAB create serpentine galleries as they feed in the phloem and outer xylem Liu et al. Resistance of Manchurian ash is hypothesized to be the result of a shared co-evolutionary history with EAB Rebek et al. Comparisons of the constitutively expressed proteomes and phenolic complements of susceptible North American and resistant Manchurian ash phloem identified four resistance-associated proteins, as well as two phenolic compounds unique to Manchurian ash.
Principal component analyses PCA from both studies confirmed that black ash is the closest North American relative to Manchurian ash section Fraxinuswhile green and white ash separate into their own clade section Melioidesas shown in previous chemical and phylogenetic studies WallanderWhitehill et al. While defense-related traits play an important role in resistance, other important traits, such as nutritional value of the feeding substrate, must also be evaluated, since high nutritional value may allow for partial compensation of host toxicity or be sufficient in its own right to differentiate resistant and susceptible hosts Haukioja et al.
Thus, we characterized the overall nutritional quality of composite samples of outer bark and phloem tissues from stems of black, green, white and Manchurian ash. We compared water content and concentrations of total protein, free amino acids, total soluble sugars and starch, macro- and micronutrients mineral nutrients and percent carbon and nitrogen.
We then used a stepwise statistical protocol to uncover differences among ash species that may have functional significance in the interaction with the insect. The resistance phenotypes of these cultivars have been confirmed in multiple common garden experiments Smith et al.
Ash dieback disease: a lament for a lost landscape
All trees were acquired from Bailey Nursery, Inc. Black, green and Manchurian ash were grown in 7-gallon pots while white ash was grown in gallon pots in a medium containing pine bark and Com-Til 6: The trees were removed from the polyhouse on 8 July and allowed to acclimate for 2 weeks.
The potted trees were arranged in a randomized complete block design with four blocks and each species present once within a block 16 trees total. All trees were 8-year-old at sampling. Black, green, Manchurian and white ash trees had mean stem diameters of 2. The trees were watered daily by hand. The basal 75 cm of the main stem, starting at the soil surface, of each of the 16 trees was cut into thirds, placed into 5-gallon ZiplocTM bags S. Johnson and Son, Inc.
Samples of phloem and outer bark phloem tissue and outer bark were about equal in thickness were excised from the main stems, flash frozen and ground into a powder using liquid nitrogen. Water content Samples for water content measurement were not ground in liquid nitrogen. Total protein extraction and analysis Total soluble proteins were extracted using a method modified from Cipollini et al. Free amino acids Free amino acids AAs were extracted using a protocol modified from Riipi et al.
The samples were incubated at room temperature for 1 h with vortexing every 15 min, centrifuged for 10 min at g and the supernatants transferred to 50 ml centrifuge tubes.
Wood ash - Wikipedia
This process was repeated and the supernatants combined. Acetone was evaporated in a chemical fume hood until the odor of acetone could not be detected.
The freeze-dried extracts were re-suspended in 1 ml of 0. New calibration AA standards of 5, 10 and 20 nmol were derivatized and run prior to samples each day. Using diagnostic mass spectral MS ions, samples were examined individually for the presence of 60 AAs. Chromatograms of samples were also examined for significant levels of other non-AA constituents.NEON by Z2 Systems, Inc.
The least concentrated of these non-AA components averaged ca. Concentrations of non-AA compounds were estimated by comparison of peak areas to the internal standard norvaline. Total soluble sugars and starch Soluble sugars were extracted using a method adapted from Kleczewski et al.
The samples were vortexed, incubated at room temperature for 10 min, centrifuged at g for 10 min and the supernatant collected. The extraction was repeated two additional times and supernatants combined. Five milliliters of extract were combined with 3 ml of Milli-Q water.
In the Baltics, it seems to have felt very comfortable and, at first unintentionally, spread out on the not very frequent Ash. It is unlikely that a single specimen of the Manchurian Ash, planted in nearby Estonia, was planted. The Wind as a probable agent As with many species, which are concerned with such "invasion", the genetic diversity in Europe is conspicuously restricted to this harmful fungus a new combination by sexual propagation cycles still exists.
The spreading probably took place successively with the wind; The spores are thus likely to have traveled the distance to England in 20 years even against prevailing wind directions in Europe. In there were some first time reports of this pathogen from the Czech Republic.
Denmark and Northern Germany were affected relatively early. Since there are many nurseries spread across Europe, it is thought whether plant transports such as in Austria have accelerated the spread of the disease Heinze et al.
The northern Mediterranean region has been largely spared of this attack, as are continental regions of the Pannonian Basin with no reports of this pathogenic invasion. But in the last few years, however, a further advancement of the disease was observed, as in Tuscany.
Although the dry, hot climate generally not suitable for the growth of this fungus, the Ash is still bound to fresh and humid soils, and this local climate, for example in large floodplains on the lowland rivers, has a beneficial effect on the pathogen.
Also the narrow-leafed ash Fraxinus angustifolia is affected by Ash-dieback. Thomas Cech, Figure 1. From the main spreading area of the Ash, in the lowlands and in the edge of the Alps, the disease spread rapidly and reached the inner alpine valleys after only a few years for example, East-Tirol no later than At the beginning of the monitoring, the course of the disease did not progress very rapidly, year by year; Rather dry-continental sites were less affected.
Sporulation and spore germination is favored by moist conditions. The progress of the disease, however, was greater, especially in more precipitous summers. Interestingly, the years and show above-average summer rainfall for, for example, St. Hot, dry summers do not like the fungus growth is over 30 degrees Celsius ; In such years the trees can recover somewhat but do not completely overcome the disease. Nevertheless, a further intensification of the disease has been observed especially in recent years since about Where observations on certain trees were repeated more frequently as in seed plants or in some forestry companies, Heinze et al.
In the off-shore area, trunk necroses occurred, and trees had to be cut in order to prevent pathways in cases of sick trees, care should be taken, since dead branches can fall.
It has been observed across Europe, that younger trees are more severely affected than the older ones. Studies on the infection of younger shoots are being done by a research group at BFW under the supervision of Dr. But it is still to be clarified whether the infection pressure is greater on the ground, and on smaller heights than in the tree-crowns of trees.
Alley and park trees and solitary trees The removal of autumn leaves in which the fruit bodies and spores of the fungus develop until the following summer has a very positive effect.
The fate of the Ash could then be similar to the Ginkgo which only survives in "human custody".
Ash dieback disease: a lament for a lost landscape - Telegraph
In this context, Heinze et al. Also, experiments tried to track the course of the disease by changing the pollen volume and by the data on the market for seeds and plants. It turned out that the issue is more complex than a simple "before-after" scenario.
In the east of Austria, Ash trees showed about two to three years of higher pollen quantities. Male blossoms produce pollen year in and year out in fluctuating intensity. Heinze, BFW A declining trend in the pollen levels has been visible since the outbreak of the disease in the eastern part of Austria, but this is probably superimposed by the effects mentioned Heinze et al.
In the Northern Alps high flowering years occur less frequently; Since was a particularly high one, the trend has generally fallen since then.
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Whereas a rearwardly shifted curve is shown in the south, The later onset of the disease, the lower density of the Ash and local effects around the pollen stations could be reasons for this Heinze et al When Seed cultivation of Ash trees practically came to a standstill The year was a particularly good one for seed production.
Almost 20 review studies were carried out and documented. Until now about 11 - 16 or on an average scarcely eight studies were made. However, now seed cultivation for Ash has practically come to a standstill Heinze et al. Plant production also shows the same trend and after a peak in 1. This also means that the few plant material that is still available for plantation is genetically not very strong. As mentioned, the close economic linkage of plant production in Europe is also relevant in this context, production centers in northern Germany, for example, might have unintentionally "cooperated" with the spread of the disease.
A book with many of these contributions with respect to the participating countries is currently being compiled. The scientific contributions will be published in a special edition of the journal "Baltic Forestry". Some of such examples are given below: In a meeting at the Braunschweig University of Technology in springthe research on "virulence" and "avirulence factors" was a major topic.
It tried to find out whether the fungus reacts negatively to some plant constituents, or whether it can be inhibited by other substances. Although many samples are being investigated, there is still no clear picture of such relationships in the metabolism of host plant and fungus. But an interesting detail was the discovery of mushroom material in seeds and roots of Ash.
A meeting in Dublin Ireland, May was focused specifically on the genetics of this pathogen in particular.