Fusarium oxysporum,F. proliferatum and F. redolens associated with basal rot of onion in Finland

In recent years in Finland, Fusarium infections in onions have increased, both in the field and in storage, and Fusarium species have taken the place of Botrytis as the worst pathogens causing post‐harvest rot of onion. To study Fusarium occurrence, samples were taken from onion sets, harvested onions and also from other plants grown in the onion fields. Isolates of five Fusarium species found in the survey were tested for pathogenicity on onion. Fusarium oxysporum was frequently found in onions and other plants, and, of the isolates tested, 31% caused disease symptoms and 15% caused growth stunting in onion seedlings. Fusarium proliferatum, a species previously not reported in Finland, was also identified. Over 50% of the diseased onion crop samples were infected with F. proliferatum, and all the F. proliferatum isolates tested were pathogenic to onion. Thus, compared to F. oxysporum, F. proliferatum seems to be more aggressive on onion. Also some of the F. redolens isolates were highly virulent, killing onion seedlings. Comparison of the translation elongation factor 1α gene sequences revealed that the majority of the aggressive isolates of F. oxysporum f. sp. cepae group together and are distinct from the other isolates. Incidence and relative proportions of the different Fusarium species differed between the sets and the mature bulbs. More research is required to determine to what extent Fusarium infections spoiling onions originate from infected onion sets rather than the field soil.     

Removal of flowers or inflorescences affects ‘Barnea’ olive fruitlet post-anthesis abscission

A typical olive (Olea europaea L.) inflorescence consists of about 20 flowers. However, in many cultivars, only one fruit develops. This is due to massive abscission of flowers and fruitlets, which occurs during the first month after anthesis. In this study, we used the olive cultivar 'Barnea' to characterize the abscission mechanism and to try to increase fruit set by increasing the number of developed fruit per inflorescence. Removing the lateral flowers 3 weeks before anthesis increased fruit set by more than 50%. Removing all inflorescences but one from a branch increased the number of developed fruits from 0.93 to 2.8 during 2017 and from 0.91 to 3.34 fruits per inflorescence in 2018. Sugar quantification in the pistil revealed that starch level is high on the day of anthesis and low 25 days later in abscised as well as in developed fruit. Soluble carbohydrates are low on the day of anthesis, low in abscised flowers/fruitlets 25 days after anthesis and high in developed fruit. Screening the natural variation found in the Israeli germplasm collection revealed that in most cultivars less than one fruit per inflorescence has developed. However, there are unique cultivars with a higher fruit set.     

Mites associated with budgerigars Melopsittacus undulatus (Psittaciformes: Psittacidae) and the first report of Ornithonyssus bursa (Mesostigmata: Macronyssidae) in Mexico

Background:Hematophagous mites affect numerous bird species, causing severe injuries to the budgerigars. Some species can cause dermatitis in humans.Aims:The purpose was to morphologically identify the mites related to budgerigars (Melopsittacus undulatus) and their nests in Yucatan, Mexico.Methods:In May 2022, a private budgerigar hatchery was visited and mites were collected from the bodies of the birds and their nests. The morphological traits of the mites were confirmed by scanning electron microscopy.Results:Four of 30 birds showed severe clinical signs of mite infestation. The Budgerigars revealed lesions in the cere, nostrils, eyelids, beak, and paws. The bird’s skin showed signs of dryness and beige coloring. The birds with severe damage also presented anorexia and had deformed paws and beaks. The parasitosis was caused by the “burrowing mites,” Knemidocoptes pilae. The burrowing mites and the Grallacheles bakeri were recovered and identified from paw scabs. To eliminate mites, a topical application of Ivermectin was administered to the necks of the birds. The dose was a single, which has a residuality of 21 days. Two drops (0.115 mg/ml) of ivermectin were applied to each bird. A gradual reduction in crusted lesions due to mite mortality was noted. The “tropical fowl mite” Ornithonyssus bursa was identified in the nests, which represents the first record in Mexico.Conclusions:Three species of mites were discovered in a single budgerigar hatchery. This emphasizes the importance of deworming birds and keeping a clean environment in their cages to reduce the potential for parasitic mite infestation.     

Age changes in extramural digestive glands of sheep and rabbits in the postembryonic period

Background:The study of the peculiarities of the anatomy of sheep and rabbits’ digestive systems is an important way to improve the efficiency of these animals’ breeding.Aim:The aim of the presented research was to study structural changes of such digestive glands as the liver and the pancreas which occur in the process of ontogenesis in sheep and rabbits.Methods:Sheep of the “Kazakh fat-tailed semi-coarse-wooled” breed (n = 8) raised in the “Sayan” private peasant agriculture and rabbits of the “Grey Giant” breed (n = 8), raised on the mini rabbit farm of the Agriculture Faculty of Shakarim University were used in the research.Two experimental animal groups were formed (of sheep, “Kazakh fat-tailed semi-coarse-wooled” breed, n = 8; rabbits, “Grey Giant” breed, n = 8). The liver and pancreas’ ontogenesis development has been studied in these animals.Results:The study presents a holistic view of the macro-microscopic structure of the liver and the pancreas of animals in crucial age periods, stages, and phases of postembryonic ontogenesis (by the example of sheep and rabbits). The authors have traced age stages of adaptive change and structural-functional change of stromal-parenchymatous structures of the liver in sheep and rabbits taking into account stages and crucial phases of development.Conclusion:Development of the liver and the pancreas are characterized by discontinuous growth in the process of postnatal ontogenesis. A crucially important period is the first months after birth, during which the weight and functionality of these organs grow rapidly.     

户外教育为基础的高校公共体育教学实践研究*

运用文献资料法、实地考察法、问卷调查法、数理统计法对高校户外教育为基础的公共体育教学中课程结构,教学设计、内容、时间分配及整体教学效果进行了实践检验和分析研究。研究表明,高校公共体育“全人教育”模式具有时代性、可行性和科学性,教学过程不仅注重体验与参与的重要性,也注重学生身体、心理、技术、组织参与等全面素质的培养,课程内容设置科学,课堂时间分配合理,整体教学效果良好,为新时期高校公共体育教育改革提供了借鉴参考。     

不同氮磷浓度对蛋白核小球藻砷富集和转化的影响

氮(N)、磷(P)是影响蛋白核小球藻生长的重要因素,通过改变培养液中N、P的浓度,可能实现对蛋白核小球藻富集砷(As)进行调控。为探讨N、P浓度对这种微藻吸收As的影响是否与其生长变化有关,采用室内培养实验,首先研究不同N、P浓度对蛋白核小球藻生长的影响;进而选择不影响小球藻生长的N(247、24.7 mg·L-1)、P(6、0.6 mg·L-1)浓度组合,设置0.8、8 mg·L-1的亚砷酸盐(As3+)和砷酸盐(As5+)处理3 d,研究N、P浓度对小球藻As富集和转化的影响。结果表明,当P浓度为6 mg·L-1时,N浓度降低到24.7 mg·L-1不会影响小球藻对As3+和As5+的富集及其胞内As形态的转化;而当N浓度为247 mg·L-1时,P浓度降低到0.6 mg·L-1则会显著增加小球藻对As3+和As5+的吸收和富集,藻细胞内As5+还原、甲基化和外排也显著增强。因此,在不影响小球藻细胞生长的条件下,P对其As富集和转化过程的影响比N更为显著。     

Immunohistochemical study on changes in gill Na+/K+-ATPase α-subunit during smoltification in the wild masu salmon, Oncorhynchus masou

Changes in immunoreactivity of Na⁺/K⁺-ATPase -subunit in gill sections of wild masu salmon (Oncorhynchus masou) during the parr-smolt transformation (smoltification) were compared with changes in gill Na⁺/K⁺-ATPase specific activity. Gill Na⁺/K⁺-ATPase specific activity increased from April and peaked in May. Immunohistochemical analysis, using an antiserum against a synthetic oligopeptide based on the conserved region of the Na⁺/K⁺-ATPase -subunit, revealed that immunoreactivity was confined to chloride cells in the surface layer of primary lamellae and the proximal end of secondary lamellae. The size and number of these cells increased gradually from February to May; however, the number of chloride cells of the secondary lamellae decreased in May. These data suggest that the synthesis of Na⁺/K⁺-ATPase and the proliferation of chloride cells occur prior to the elevation of enzyme activity. Moreover, it is likely the proliferation and hypertrophy of chloride cells on primary lamellae prepare smolts for entry into seawater and migration in the ocean.     

The role of flatfishes in the organization and structure of the eastern Bering Sea ecosystem

We evaluated the role of flatfishes in the organization and structure of the eastern Bering Sea ecosystem using the Ecopath/Ecosim approach. As basic input data for the Ecopath/Ecosim model, we used estimates of biomass from bottom trawl surveys and age-structured population models, production/biomass (P/B) ratio, consumption/biomass (Q/B) ratio, diet composition (DC), and fisheries harvests for each component of species or species groups. We estimated the trophic level of each component, niche overlaps among flatfishes, and the impacts of competition and predation on flatfish species in the eastern Bering Sea ecosystem. Based on those estimates, we developed the tropho-dynamic structure of the ecosystem, and the model was used to simulate ecological effects of fishery exploitation patterns. No single flatfish species appeared to have a profound and uniquely important role in the organization and structure of the ecosystem. Instead, the most important component among the guild of flatfish species appeared to be yellowfin sole Pleuronectes asper, which had greater biomass than other flatfish and a relatively diverse diet among the small flatfish species. Pacific halibut Hippoglossus stenolepis, Greenland turbot Reinhardtius hippoglossoides, and arrowtooth flounder Atheresthes stomias were important keystone predators in the eastern Bering Sea ecosystem together with some groups of marine mammals and sea birds. Intra flatfish complex cannibalism was not observed, however, substantial diet overlaps were common in the flatfish guild system.     

Antioxidative Effect of Chlorella Pyrenoidosa Protein Hydrolysates and Their Application in Krill Oil-in-Water Emulsions

Chlorella pyrenoidosa is an excellent source of protein, and in this research, we assessed the antioxidant and emulsifying effects of Chlorella protein hydrolysate (CPH) using neutral proteases and alkaline proteases, as well as the properties of CPH-derived krill oil-in-water (O/W) emulsions. The CPHs exhibited the ability to scavenge several kinds of free radicals, including 1,1-diphenyl-2-picrylhydrazyl (DPPH), O₂⁻, hydroxyl, and ABTS. Additionally, the CPHs (5 mg/mL) scavenged approximately 100% of the DPPH and ABTS. The CPHs showed similar emulsifying activities to Tween 20 and excellent foaming activities (max FS 74%), which helped to stabilize the krill oil-in-water emulsion. Less than 10 mg/mL CPHs was able to form fresh krill oil-in-water emulsions; moreover, the CPHs (5 mg/mL) in a krill O/W emulsion were homogenous, opaque, and stable for at least 30 days. Based on their inhibitory effects on the peroxide value (POV) and thiobarbituric acid reactive substances (TRABS), the CPHs were found to be able to inhibit lipid oxidation in both emulsifying systems and krill O/W emulsions. Thus, the CPHs could improve superoxide dismutase (SOD) activities by 5- or 10-fold and decrease the high reactive oxygen species (ROS) level caused by the addition of H₂O₂ in vitro. In conclusion, health-promoting CPHs could be applied in krill oil-in-water emulsions as both emulsifiers and antioxidants, which could help to improve the oxidative and physical stability of emulsions.     

粪肥施用对土壤团聚体的影响——Meta分析

粪肥施用为土壤输入大量有机质与养分,能影响土壤团聚体的形成和稳定性,大部分研究主要认为粪肥施用促进土壤大粒径团聚体的形成(marcoaggregate,≥0.25 mm),但进一步细分是对大团聚体(large marcoaggregate,>2 mm)还是小团聚体(small marcoaggregate,2 ~ 0.25 mm)的影响更大,研究存在较大差异。本文使用Meta分析收集了36篇相关文献,共267个团聚体数据,发现施用粪肥能显著增加土壤大团聚体和小团聚体含量,分别增加了95% 和17%,同时减少了土壤微团聚体(microaggregates,0.25 ~ 0.053 mm)和土壤粉黏颗粒(silt-plus and clay-size particles,<0.053 mm)含量,分别减少了14% 和20%。本文还从土壤因素、粪肥因素、气候因素3个角度的解释变量来分析粪肥施用对土壤团聚体影响不同的原因,结果发现土壤类型、土壤pH、粪肥种类和年均气温、年均降水量是造成不同研究结果差异的主要原因。