Structure of pollarded oak forest in relation to aspect in Northern Zagros,Iran

We analyzed the structure of pollarded oak forest and biometric indices of pollarded oak species in relation to aspect in northern Zagros forests, western Iran. A number of 319 circular plots (0.1 ha) were established using a systematic random method over the study area. In each plot, for all trees (diameter at breast height ≥5 cm) diameter was measured and tree species was recorded. Total height, trunk height, and major and minor diameter axis of the crown of two trees in each plot (nearest tree to the center of the plot and the largest tree in term of diameter) were measured. As the dispersion of slope and altitude classes in the study area were identical, the effect of these factors was assumed to be constant. To evaluate the effect of aspect on biometric indices of oak trees a comparison was used for each oak species separately. The results indicated that the forest species composition differed statistically significant in main aspects except for easterly and westerly aspects (P < 0.01). The diameter of similar oak trees was significantly different except for Lebanon oak in northerly and southerly and Gall oak in easterly and westerly aspects (P < 0.01), but there was no significant difference between the total height and crown area of similar oak species in different aspects. Differences in diameter, height, and crown area distributions showed a significant difference in main aspects. The basal area and tree density in northerly and southerly aspects were significantly different (P < 0.05).     

Simultaneous Dynamics and Kinetics of Soil Phosphorus Under Different Fertilizer Systems During Two-Growth Seasons of Maize

This study investigated phosphorus (P) dynamics and kinetics in calcareous soil under inorganic, organic, and integrated (inorganic+organic) fertilizer systems during two growing seasons of maize in two soil depths (0–0.15 and 0.15–0.30 m). A field experiment was conducted with 150, 300, and 400 kg ha^?1 triple superphosphate (TSP), 7.5 and 15.0 ton ha^?1 (on dry matter basis) farmyard manure (FYM), and integrated systems. In order to analyze Olsen P, soil samples were collected in 30-day-intervals after planting. The results showed that at the end of the two growing seasons of maize, the lowest magnitudes of Olsen P_0–0.15 m were 6.0, 6.8, 7.4, and 7.6 mg kg^?1 for the control, 7.5 FYM, 15 FYM, and 150 TSP, respectively. The highest magnitudes of Olsen P_0–0.15 m were 12.4, 11.5, 11.4, and 11.1 mg kg^?1 for 300 TSP+15 FYM, 400 TSP+7.5 FYM, 400 TSP+15 FYM, and 300 TSP+7.5 FYM, respectively. The same trends were observed for Olsen P_{0.15–0.30 m}. Heterogeneous diffusion model demonstrated that Elovich equation could best describe the experimental data (mean; R² = 0.98, SE = 0.29). The highest P supply rates (PSR) were 4.73, 3.91, and 3.86 mg kg^?1day^?1 (days after application) for 400 TSP, 400 TSP+15 FYM, and 300 TSP, respectively. The models of P supply capacity of soil could estimate P supply of soil under different fertilizer systems (R² = 0.84–0.95). The present study improved the understanding of the capacity and rate of P supply by considering P uptake by grain maize. Fertilizer recommendations depend on the accessibility of fertilizer types suggested to help choose the best fertilizer systems.     

Detection of mistletoe infected trees using UAV high spatial resolution images

Journal of Plant Diseases and Protection - Remote detection of aerial parasitic plants in forests is imperative in precision forestry, as it can help to manage tree stands and to monitor forest...     

Development of species‐specific PCR primers on rDNA for the identification of European Armillaria species

Attempts to design species‐specific PCR primers from six European Armillaria species in the ribosomal RNA genes are reported. Primers were developed on the basis of the nucleotide sequence variability of the internal transcribed spacers (ITS) and the intergenic spacer (IGS1) of the ribosomal DNA. Four sets of primers gave specific PCR products for Armillaria tabescens, Armillaria mellea and Armillaria ostoyae. However, due to the high sequence similarities between Armillaria borealis and Armillaria ostoyae and between Armillaria cepistipes and Armillaria gallica no species specific amplification was obtained for these taxa.     

Infection and colonization of strawberry by <Emphasis Type="Italic">Gnomonia fragariae</Emphasis> strain expressing green fluorescent protein

Gnomonia fragariae is a poorly studied ascomycete, which was recently demonstrated to be a cause of severe root rot and petiole blight of strawberry. The pathogen was genetically transformed with the GFP as a vital marker and hygromycin resistance gene. Several stable transformants were obtained, which did not differ in their phenotype from the wild type isolate. Using one of the GFP-tagged isolates the infection process and colonization of roots and petioles of host plant by the pathogen were studied. Fluorescence microscopy examinations of the inoculated plants at different time points showed that plant infection occurs 24 h after inoculation and intensively continues during first 3 days. The specific penetration sites on epidermal cells and preferences in colonization for certain root and petiole tissues were observed. The pathogen intensively colonized and destroyed cortex of roots and petioles and spread rapidly longitudinally within intercellular spaces. The petioles were colonized by the hyphae, which grew mostly in the intracellular spaces of the cortical cells while in the roots the intracellular growth of hyphae occurred only in the later stages of infection. The fungus was also capable to infect the vascular tissues of petioles although these were not the primary tissues colonized by the pathogen. The mature ascomata were formed on the infected petiole bases several weeks after the inoculation. This study presents a genetic transformation method for Gnomonia fragariae and it demonstrates details on infection process and colonization of root, crown and petiole tissues of strawberry by the pathogen.     

Oocyte maturation,embryo development and gene expression following two different methods of bovine cumulus-oocyte complexes vitrification

Objective

To examine the maturational competence, embryo development and expression of genes involved in oocyte maturation and cumulus expansion (GDF9, BMP15, HAS2, TNFAIP6, FGF17 and FSHr) following two standard methods of bovine COCs vitrification.

Methods

Bovine cumulus-oocyte complexes (COCs) were aspirated from slaughtered ovaries and then distributed into three groups: non-vitrified COCs (control), vitrification 1 group (V1); vitrification was performed by 15% ethylene glycol (EG) and 15% DMSO in holding media (TCM-199 with 20% FCS); and vitrification 2 group (V2); vitrification was performed by 40% EG in holding media. After vitrification, COCs were warmed in two steps and cultured and then evaluated for nuclear maturation, embryo development and gene expressions.

Results

The mean (±SD) percentages of nuclear maturation and blastocyst/cleaved were higher in control group (79.5 ± 8.0 and 31.0 ± 5.1%) than the V1 (34.8 ± 9.1 and 4.4 ± 5.1%) and V2 (47.8 ± 11.7 and 7.1 ± 5.8%) groups (P < 0.05), respectively. Further, COCs in V2 group showed higher mean (±SD) percentages of cleavage compared to V1 group (31.8 ± 1.0 vs 21.7 ± 2.8%; P < 0.05). GDF9 and BMP15 expression levels were higher in COCs in the control than of the vitrification groups (P < 0.05). In addition, expression level of GDF9 and BMP15 was higher in V2 group than in V1group (P < 0.05). The expression of HAS2 and FGF17 in V1 group was lower (P < 0.05) than that of the V2 groups.

Conclusions

Expression of oocyte maturation genes was affected by vitrification procedure and conditions. Using EG alone for vitrification of bovine immature COCs, resulted in higher expression of GDF9, BMP15 and production of more in vitro matured and cleaved oocytes.

     

A new plant pathogenic sterile white basidiomycete from Australia

A sterile white fungus was isolated from the healthy looking roots of buffalo grass (Stenotaphrum secundatum) grown on cleared bush land in Perth, Western Australia. The fungal strain was pathogenic on 12 plant species screened under the greenhouse conditions. The clamp connections and dolipore septa indicated that the isolate was a Basidiomycete. Mycelial features, growth rate at different temperatures, as well as pathogenicity patterns of this sterile white basidiomycete (SWB) were distinctly different from those of a strain with a similar morphology, ATCC 28344, previously described as a pathogen in Florida and Georgia (USA). All attempts to induce sporulation failed. The isolates were also compared using the nucleotide sequence analysis of the ribosomal DNA array. Approximately 1 kbp of the 5 end of the large subunit ribosomal RNA gene, complete sequences of the small subunit ribosomal RNA gene and the entire ITS region (including ITS1, ITS2 and 5.8S gene) were sequenced for the purpose. The obtained sequences were compared with the homologous regions of other genera of Agaricales available in GenBank. Relatively low sequence similarities between the American and Australian strains, as well as the phylogenetic analysis of the studied regions has suggested that these two fungi belong to different genera. Interesting results were achieved in the case of the large subunit ribosomal DNA since this region has been widely studied for taxonomy of Basidiomycetes. The Australian strain 3034 appeared to be closely related to the genus Campanella and the American SWB was identified as belonging to the genus Marasmius, possibly to M. graminum. Our data suggest that the Australian strain is a novel pathogen, and is different from the American SWB isolates described to date.     

Influence of Metallic Elements Exuded from Wood Based Fly Ash on Treatment of TMP Effluent北大核心CSCD

In the process of thermomechanical pulping(TMP) effluent treatment using wood based fly ash (FA) as reactant, inorganic metallic ions can exude into the effluent from FA complex. In order to determine the metallic elements in FA would flocculate and remove the organics in the effluent under the alkaline condition, the removal behaviors of organic material were investigated by means of simulation with different kind of metallic ions addition at various dosage levels and adjusting pH value of TMP effluent, respectively. It concluded that the metallic ions combined with organics precipitate simultaneously under the alkaline condition by charge neutralization and H-bond to form large particles. The removal rates increased with the increment dosage of Mg2+ and Fe3+, while the Ca2+ and Al3+ would not be affected by their dosage under the alkaline condition. When the pH values were 10 and 12, respectively, the removal capability of Ca2+ and Mg2+ was maximum at pH value 12, while Al3+ achieved peak removal rate at pH 10. The removal efficiency from Fe3+ kept constant between pH value 10 and 12. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

Application of robust procedures for estimation of breeding values in multiple-trait random regression test-day model

Robust procedures for estimation of breeding values were applied to multiple‐trait random regression test‐day (TD) model to reduce the influence of outliers on inferences. Robust estimation methods consisted of correcting selected observations (defined as outliers) in the process of solving mixed‐model equations in such a way that ‘new’ observations gave residuals (actual observation minus predicted) within k residual standard deviations for a given day in milk in 305‐day lactation. Data were 980 503 TD records on 63 346 Canadian Jersey cows. Milk, fat, protein and somatic cell score in the first three lactations were analysed jointly in the model that included fixed herd‐TD effect and regressions within region–age–season of calving, and regressions with random coefficients for animal genetic and permanent environmental effects. All regressions were orthogonal polynomials of order 4. Robust procedures for k = 1.5, 2.0, 2.5, 2.75 and 3.0 were contrasted with the regular best linear unbiased prediction (BLUP) method in terms of numbers and distributions of outliers, and estimated breeding values (EBV) of animals. Distributions of outliers were similar across traits and lactations. Early days in milk (from 5 to 15) were associated with larger frequency of outliers compared with the remaining part of lactation. Several, computationally simple, robust methods (for k > 2.0) reduced the influence of outlier observations in the model and improved the overall model performance. Differences in rankings of animals from robust evaluations were small compared with the regular BLUP method. No clear associations between changes in EBV (rankings) of top animals from different methods and the occurrence of outliers were detected.     

Gnomonia fragariae, a Cause of Strawberry Root Rot and Petiole Blight

Gnomonia fragariae has been occasionally listed among the fungi associated with diseased strawberry plants. However its pathogenicity has not been established. During the investigation on strawberry decline in Latvia and Sweden, a fungus was repeatedly recovered from discoloured root and crown tissues of severely stunted plants. Attempts to induce sporulation of the isolates grown on several agar media resulted in the formation of mature ascomata only on potato carrot agar and oatmeal agar. On morphological grounds and comparisons with reference herbarium specimens these isolates were identified as Gnomonia fragariae. The pathogenicity of the fungus was evaluated initially in the detached leaf assay and subsequently in three bioassays on strawberry plants. All the bioassays showed that G. fragariae was pathogenic on strawberry and capable of causing severe root rot and petiole blight. The symptoms that developed in the greenhouse experiments closely resembled those observed in the fields. The fungus did not cause rapid plant death but growth and development of inoculated strawberry plants was severely affected. To our knowledge this is the first time when pathogenicity of G. fragariae as a root rot pathogen has been clearly established. Our study shows that G. fragariae is one of the serious pathogens involved in the root rot complex of strawberry in Latvia and Sweden.