Early stages of Margaritifera margaritifera glochidiosis in Atlantic salmon: Morphopathological characterization

Freshwater mussels of the order Unionida encyst into the fish mucosa to metamorphose and complete their life cycle, causing a parasitic disease known as glochidiosis. This parasitic stage represents a bottleneck for the survival of naiads, particularly for critically endangered species as Margaritifera margaritifera; however, little is known about the events occurring during this critical stage. Therefore, this study aimed to histologically characterize the development of M. margaritifera glochidiosis in Atlantic salmon to get insight into the pathogenesis of this interaction. Fish exposed to glochidia were sampled during the first 44 days post-exposure, and organs were observed by stereomicroscopy and light microscopy. Glochidia attached to the gills by pinching the lamellar epithelium, whereupon an acute proliferative branchitis engulfed most of the larvae. However, during the first 14 days, a severe detachment of unviable glochidia occurred, associated with the presence of pleomorphic inflammatory infiltrate and epithelial degeneration. In the cases where larvae remained attached, a chronification of the lesions with none to scarce inflammation was observed. These results provide key information to better understand the complex host–parasite interaction during the early stages of glochidiosis and provide valuable information to optimize artificial rearing of naiads in conservation of threatened freshwater mussel populations.     

杂色蚕豆新品种“清蚕2号”选育初探

2010年夏在慈溪市白沙路鲜食白花大粒蚕豆大田中发现因小黑蚕豆和白花大粒蚕豆自然杂交而产生变异的F0代变异单株，然后经F1到F5代的连续单株选择，经过F6代的株系选择和F7代的优系繁育，育成了杂色蚕豆新品种——清蚕2号。其株高约90 cm，分枝6～7个，花瓣上部白色，花托处红色，每荚1～3粒， 3粒荚占比仅10%，干豆形状短圆，干豆色泽底色为淡黄色，其侧面有八字形棕褐色条带，豆眼黑色，百粒质量为100 g。“清蚕2号”株型紧凑，植株中等，整齐度高，田间性状稳定，长势较旺盛，抗病性较强，适应性、抗逆性强，结荚多，产量高，品质好。     

Two filamentous microalgae as feed ingredients improved flesh quality and enhanced antioxidant capacity and immunity of the gibel carp (Carassius auratus gibelio)

A 40‐day experiment was conducted to investigate the effects of two filamentous microalgae as feed ingredients on growth performance, tissue fatty acid profiles, pigmentation and immunity of gibel carp (204.83 ± 2.17 g, mean ± SD). Three diets (control, Oedocladium sp. and Tribonema sp.) were formulated. In the control diet, no microalgal meal was added and into the Oedocladium and Tribonema diets were added 40 g/kg Oedocladium sp. meal and 50 g/kg Tribonema sp. meal, respectively. Compared to the control, the addition of Oedocladium sp. and Tribonema sp. had significant effects on tissue fatty acid profiles, antioxidant capacity and immunity without compromising growth, body composition and pigmentation. The addition of Tribonema sp. and Oedocladium sp. significantly increased the EPA, DHA profiles and the ratio of n‐3/n‐6 polyunsaturated fatty acids, and simultaneously decreased the n‐6 polyunsaturated fatty acids profile in fish muscles. Moreover, addition of Tribonema sp. to the diet significantly increased muscle palmitoleic profile and EPA + DHA contents. Furthermore, the addition of either microalga significantly increased the total superoxide dismutase activity level and the complement 3 and immunoglobulin M contents in the plasma. These results demonstrate that Oedocladium sp. and Tribonema sp. can be used as feed ingredients to improve flesh quality and increase the immunity of fish.     

Aurantiochytrium sp. meal as DHA source in Nile tilapia diet,part II: Body fatty acid retention and muscle fatty acid profile

Nile tilapia juveniles (8.35 ± 0.80 g) were fed on four levels (0.0%; 0.5%; 1.0%; 2.0%, 4.0%) of Aurantiochytrium sp. meal (ALL‐G‐RICH?), a source of docosahexaenoic acid (DHA). The 1% Aurantiochytrium sp. meal diet was compared to a control diet, which contained the same amount of DHA as cod liver oil (CLO) at 1.7% diet. Groups of 25 fish were stocked in 100 L tanks and fed twice daily until apparent satiation, for 57 days, at 28°C. Increasing dietary Aurantiochytrium sp. meal reduced the body retention of DHA and n‐3 polyunsaturated fatty acids (n‐3 PUFA) but increased the body retention of alpha‐linolenic (α‐LNA), linoleic (LOA) and n‐6 polyunsaturated fatty acids (n‐6 PUFA). Fatty acid profile in tilapia muscle was affected by increasing dietary inclusions of Aurantiochytrium sp. meal, with an increase in DHA, α‐LNA, n‐3 PUFA and n‐3 long chain‐polyunsaturated fatty acids (n‐3 LC‐PUFA) but a decrease in monounsaturated fatty acids (MUFA), n‐6 PUFA and n‐6 long‐chain polyunsaturated fatty acids (n‐6 LC‐PUFA). There was a larger body retention of DHA, α‐LNA, LOA, n‐3 PUFA and n‐6 PUFA fatty acids and a higher percentage of DHA, n‐3 PUFA and n‐3 LC‐PUFA in muscle fatty acid profile in fish fed on CLO diets than in those fed on 1% Aurantiochytrium sp. Therefore, Aurantiochytrium sp. meal is an alternative source of DHA for Nile tilapia diets.     

真鲷虹彩病毒自然感染杂交石斑鱼“褐龙斑”的组织病理分析

褐龙斑是雌性褐石斑鱼(Epinephelus bruneus)和雄性鞍带石斑鱼(E. lanceolatus)杂交产生的子代。作为杂交石斑鱼的新品种，国内外尚没有褐龙斑疾病的报道。2017年7月，某养殖场褐龙斑出现急性死亡，10 d内累积死亡率高达80%。现场调查发现，病鱼外观无明显异常，但反应迟钝，伏底死亡。临床检查和剖检可见脾和肾严重肿大、易碎。组织病理切片观察发现，各组织中存在数量不等的嗜碱性、细胞质均一、直径为10~15 µm的肿大细胞。超薄组织切片中发现，肿大细胞胞质内存在大量直径为130~150 nm的虹彩病毒样颗粒。使用特异性的PCR引物，从病鱼脾、头肾等组织中均检测到真鲷虹彩病毒(Red seabream iridovirus, RSIV)的高强度感染。测定了该病毒主要衣壳蛋白(Major capsid protein, MCP)基因1362 bp的全长编码区，构建了19种(株)虹彩病毒系统发育树，结果显示，该病毒属于虹彩病毒科肿大细胞病毒属RSIV类群。本研究首次描述了褐龙斑虹彩病毒病的组织病理特征，揭示了褐龙斑是RSIV新的敏感宿主，为杂交石斑鱼病毒病的诊断与防治提供了重要的参考依据。     

Relationship Between Postural Stability and Paraspinal Muscle Adaptation in Lame Horses Undergoing Rehabilitation

Postural stability maintains balance, protects the spinal column, and allows accurate responses to destabilizing forces. The musculus multifidus (m. multifidus) is the major postural muscle located adjacent to the vertebrae along the length of the spinal column. Increased cross-sectional area (CSA) of the m. multifidus has been demonstrated in horses after a rehabilitation strengthening exercise program; however, correlation with functional postural stability has not been shown. The objective of the present study is to evaluate the relationship of the thoracolumbar m. multifidus CSA and measures of postural sway performance in lame horses undergoing rehabilitation exercises in clinical cases. Seven client-owned horses admitted to the equine rehabilitation service were included in the study. M. multifidus CSA was measured via ultrasonography at the start of a rehabilitation program (initial evaluation) and after 12 weeks of rehabilitation exercises (final evaluation). Postural sway data were also measured at initial and final evaluation. A significant increase in m. multifidus CSA was seen from initial to final evaluation. A moderate to strong correlation was present between m. multifidus CSA and postural sway variables. These results suggest that there is an association between postural stability and m. multifidus hypertrophy in lame horses undergoing individualized rehabilitation programs. However, more research is needed to provide a definitive answer on the nature of this relationship. Ideally, specific performance tests would better define and examine the relationship in which to guide clinicians in rehabilitation protocol development.     

茶树新品种--梦茗

"梦茗"系从安徽省岳西县来榜镇优良地方群体种中采用单株选育法育成的适制绿茶新品种。经安徽省内品比、推广示范和全国区试,发现"梦茗"物候期与福鼎大白茶相当,属早生种。品质优异,全国区试3个点感官审评总分均高于对照;内含物含量高,氨基酸含量4.9%、茶多酚总量26.9%、水浸出物总量40%。产量高,品比试验高于福鼎大白茶26.45%,全国区试产量与对照相当。抗旱能力强,抗寒能力与对照相当。     

不同小麦品种小麦白粉病发病程度及其田间发生动态分析

【目的】研究新冬60号、新冬57号、新冬40号和新冬20号小麦白粉病危害程度和田间发生动态,为科学防控小麦白粉病提供理论依据。【方法】采用定期定点调查的方法,系统调查不同品种小麦白粉病发生情况。【结果】新冬60号、新冬57号、新冬40号小麦白粉病田间发生动态基本一致。新冬60号、新冬57号、新冬40号和新冬20号小麦白粉病病情指数最高分别为8.22、7.11、37.63和25.48。新冬60号和新冬57号小麦白粉病田间发生程度极显著轻于新冬40号和新冬20号,新冬40号小麦白粉病田间危害程度极显著重于新冬20号。【结论】新冬60号和新冬57号小麦白粉病田间危害程度极显著轻于新冬20号,可根据田间发病情况,合理减施农药。新冬40号小麦白粉病田间发生程度极显著重于新冬20号,应加强对小麦白粉病的预防。     

扁杆藨草持续危害对棉花农艺和经济性状的影响

【目的】研究扁杆藨草持续危害对棉花的影响,为棉田该杂草科学防治提供依据。【方法】扁杆藨草种群密度设为60 株/m² ,测定其持续危害0、10、20、30、40、50 、60 d和全生育期棉花株高、茎粗、主茎节数、结铃数、单铃重、产量和纤维品质指标。【结果】棉花株高和茎粗随扁杆藨草危害持续期延长而减小。扁杆藨草持续危害期小于30 d,对棉花主茎节数和果枝数影响不显著,大于30 d则显著减少。扁杆藨草持续危害期对棉花中部和下部果枝结铃数影响不显著,显著引起上部果枝结铃数、单铃重减少。扁杆藨草持续危害期大于10 d,可使棉花产量显著减少,导致棉纤维品质指标下降。【结论】依据棉花产量指标,扁杆藨草防除应不晚于棉花打顶前30 d。     

烟草粉螟不同烟叶存放区域消长规律

为探明烟草粉螟在烟叶仓储时的发生规律，以便实施精准防控。在施秉县不同烤房群、烟农 库房及收购点仓库，利用性诱剂对烟草粉螟进行监测。结果表明烟草粉螟在不同烟叶存放区域的始 发期、高峰期和终结期都不尽相同，同一种存区域的烟草粉螟消长规律也不相同。