淡紫拟青霉菌料防治大豆胞囊线虫的后效研究

淡紫拟青霉不同菌株的培养菌料，施２２５ｋｇ／ｈｍ２，对大豆胞囊线虫不但当年有４５％～６９％的较好防效，而且第２年和第３年仍然有２２．５％～３７．７％和７．３％～２２．９％的后效，即空胞囊和被寄生的胞囊数量增加。     

Significance of ABC transporters in fungicide sensitivity and resistance

ATP-binding cassette (ABC) transporters are members of a protein superfamily which can be responsible for efflux of drugs from cells of target organisms. In this way, the transporters may provide a mechanism of protection against cytotoxic drugs. In laboratory-generated mutants of fungi, overproduction of ABC transporters can cause multi-drug resistance to azoles and other non-related toxicants. The impact of this mechanism of resistance in field populations with decreased sensitivity to azoles remains to be established. Inhibitors of ABC transporter activity may synergize activity of azoles to populations of both sensitive and azole-resistant pathogens. The natural function of ABC transporters in plant pathogenic fungi may relate to transport of plant-defence compounds or fungal pathogenicity factors. Therefore, inhibitors of ABC transporter activity may act as disease control agents with an indirect mode of action. ©1997 SCI     

Differential expression of molecular rust resistance components have distinctive profiles in <Emphasis Type="Italic">Coffea arabica</Emphasis> - <Emphasis Type="Italic">Hemileia vastatrix</Emphasis> interactions

Countering the economic hurdle caused by coffee leaf rust disease is most appealing at this time as it has posed a major threat to coffee production around the world. Establishing differential expression profiles at different times following pathogen invasion in both innate and acquired immunities unlocks the molecular components of resistance and susceptibility. Suppression subtractive hybridization (SSH) was used to identify genes differentially over-expressed and repressed during incompatible and compatible interactions between Coffea arabica and Hemileia vastatrix. From 433 clones of expressed sequence tags (ESTs) sequenced, 352 were annotated and categorized of which the proportion of genes expressed during compatible interaction were relatively smaller. The result showed upregulation and downregulation of various genes at 12 and 24 h after pathogen inoculation in both interactions. The use of four different databases in searching for gene homology resulted in different number of similar sequences. BLASTx against EMBL-EBI (European Molecular Biology Laboratory-European Bioinformatics Institute) database being with the maximum (100%) hits for all the annotated sequences. RT-qPCR analysis of seven resistance-signaling genes showed similar expression patterns for most of the genes in both interactions, indicating these genes are involved in basal (non-specific) defense during which immune reactions are similar. Using SSH, we identified different types of resistance related genes that could be used for further studies towards resistant cultivar development. The potential role of some of the resistance related proteins found were also discussed.     

Reovirus infection in psittacine birds (Psittacus erithacus): morphologic and immunohistochemical study

In this paper we report on an outbreak of reovirus, herpesvirus (Pacheco disease), and/or mycosis infection (Aspergillus spp. and Zygomyces spp.) affecting a batch of young African grey parrots (Psittacus erithacus), with 80% morbidity and 30% mortality. Study material was taken from five birds (four dead and one euthanatized) with a range of clinical symptoms (depression, diarrhea, respiratory symptoms). Diagnosis was confirmed by immunohistochemical detection of avian reovirus, electron microscopy, and virus isolation. Viral antigen of reovirus was detected mainly in large mononuclear cells in the bursa of Fabricius and the spleen, pancreas epithelial cells, and circulating cells; lymphoid organs displayed the largest number of immunopositive cells and severe lymphocyte depletion. Bacteriologic study was negative. Reovirus infection was common in all birds studied, whereas Pacheco disease and mycosis were found in only some, suggesting that reovirus could be the initial cause triggering the outbreak and facilitating infection by other agents and their swift spread through the batch.     

Characterization and antioxidant potential of Brazilian fruits from the Myrtaceae family

The objective of this study is to evaluating the Brazilian biodiversity through physicochemical characterization and determination of antioxidant potential of three species from the Myrtaceae family, namely yellow guava (Psidium cattleyanum Sabine), guabiroba (Campomanesia xanthocarpa O. Berg), and uvaia ( Eugenia pyriformis Cambess). Guabiroba had the greater quantity of phenolic compounds (9033 mg chlorogenic acid/100 g) and vitamin C (30.58 mg/g) and showed the best TSS/TTA (total soluble solid/total titratable acid) ratio (45.12). For the ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic) method, the guabiroba (507.49 μM Trolox/g) presented the highest antioxidant potential; however, in the DPPH (2,2-diphenyl-1-picrylhydrazyl) method, uvaia (170.26 g/g DPPH) and guabiroba (161.29 g/g DPPH) were not statistically different. The uvaia outranked the other fruits with respect to its high carotenoid (909.33 μg/g) and vitamin A (37.83 μg/g) contents, and the yellow guava, although showing a lower bioactive compound content and antioxidant activity, nevertheless presented much higher values than many traditionally consumed fruits.     

Influence of Land Use on the Physical Properties of Chernozems in the Forest-Steppe Zone of Western Siberia

Eurasian Soil Science - The land use type and agricultural practices significantly affect the aggregate state and many physical properties of soils. In this study, we provide a comparative...     

Physico‐chemical characterization and in vitro digestibility of commercial feeds used in weaning of marine fish

Six different commercial feeds used in weaning and postweaning of marine fish were analysed from the perspective of some of their main physico‐chemical features and in vitro digestibility. While the range of particle sizes in dry state closely agreed to those claimed by the producing companies, dramatic changes were observed after suspension in water. Sedimentation rates measured in some of the feeds with higher particle sizes may be too high to ensure intake by young fish. The label claims of the products overestimate the amount of total protein but underestimate that of lipids. The analysis of amino acid profiles evidenced important differences in total amino acid composition between feeds of the same company but a great similitude in the profile of free amino acids (FAA). The evaluation of leaching evidenced that the fraction of FAA, which represented <2% of dry matter of the feeds, is quickly released in water, acting mainly as attractants. The in vitro digestibility assay evidenced significant differences in the bioaccessibility of the nitrogen fraction in some of the feeds by the digestive proteases of the sea bream (Sparus aurata).     

The sharks of South East Asia – unknown,unmonitored and unmanaged

Sharks fisheries have declined globally due to over‐ and unregulated fishing. As with many collapsed and unmonitored coastal fisheries, information is difficult to obtain, yet it is important to understand the historical changes determining population trends and evaluate the current status of sharks in order to conserve these vulnerable species. Here, we document for the first time the history and general condition of the shark fisheries of Southern China, specifically Hong Kong, and Guangdong, Fujian and Hainan Provinces. This study shows, through the use of historical literature and anecdotal accounts, including fisher interviews, that all known shark fisheries in the region collapsed between the 1970s and the 1990s. Of the 109 species present historically in the South China Sea, only 18 species were recorded in current market surveys, of which all were landed as bycatch and 65% were below the size of sexual maturity. Markets are dominated by smaller species, including the spadenose shark (Scoliodon laticaudus) and the whitespotted bambooshark (Chiloscyllium plagiosum). Marketed large shark species are almost all below the size of sexual maturation, evidence of growth overfishing and a factor in recruitment overfishing. Some species, like the whale (Rhincodon typus) and basking sharks (Cetorhinus maximus), are clearly vulnerable to local extinction without intervention. Given the inherent vulnerability of sharks and the overfished states of many sharks, there is clearly an urgent need to formulate impacting conservation and management plans for these rapidly declining species in a region that has the highest demand for shark products globally.