利用太空诱变、AFLP技术及日光温室加代选育航椒3号辣椒一代杂种

选择天水羊角椒、甘农线椒2个辣椒品种原种干种子,搭载在"神州3号"飞船上进行太空诱变处理.收回种子后,采用田间观察和AFLP技术相结合的方法,检测太空诱变处理的效果.利用日光温室进行加代选育,每年选育两代.选择优良变异,通过自交,选育优良自交系;同时,配制杂交组合,选育优良一代杂种.结果表明:太空诱麦处理后,2个辣椒品种在太空诱变处理后的第一代就产生了明显变异,自交4代后选育出了高纯度自交系.对太空诱交、AFLP技术、日光温室加代选育等技术集成创新,显著地提高了育种效率,仅三年时间选育出了极早熟、优质、高产、抗逆、广适的辣椒一代杂种"航椒3号".     

中药硼砂研究进展

中药硼砂的提取工艺由结晶法、絮凝剂法发展为碱解法及碳碱法.硼砂除了具有抗肿瘤、消毒防腐、抑菌、抗真菌和抗病毒作用外,还能对物质代谢产生影响.硼砂是低毒蓄积性毒物,对实验动物具有致畸性,但未见致突变性和致癌性,硼砂有过敏现象和使用禁忌.在人医上,硼砂用于皮肤黏膜的消毒防腐、氟骨症、足癣、牙髓炎、霉菌性阴道炎、宫颈糜烂、褥疮、痤疮、外耳道湿疹、疱疹病毒性皮肤病、癫痫的治疗,近年来还用于肿瘤的治疗.在动物医学上,硼砂用于鸡喉气管炎、山羊传染性脓疱病、猪支原体肺炎、牛慢性黏液性子宫内膜炎的治疗,作为饲料添加剂也备受人们的关注.     

应用STAR模型研究海州湾小黄鱼春季资源量的时空分布

根据2011年、2013—2016年春季在海州湾进行的渔业资源调查数据,应用结构化加性回归(structured additive regression, STAR)模型框架,结合delta方法,根据对空间数据的不同处理方式构建了5种物种分布模型,并比较各模型对出现概率和资源量2种数据类型的拟合效果、残差空间独立性和预测性能。结果显示,加入空间项后模型拟合效果提升,残差空间自相关性显著降低,且正态模型和delta模型的提升较二项模型明显。空间加性模型(geoadditive models)的AIC值在二项模型和正态模型中均为最低,较无空间项广义可加模型(generalized additive model, GAM)分别下降7.60和144.90。模型拟合上,变系数模型(varying coefficient models, VCM)的决定系数和AUC均最高,分别为0.68和0.94。预测性能上,空间加性模型交叉验证的AUC值为(0.793±0.100)最高,均方根误差(RMSE)值为(21.65±4.83)最低,表明对小黄鱼出现概率和资源密度的估计均最准确。在最优模型的基础上,根据无...     

饲料添加剂调节畜禽肠道菌群及其生长性状的研究进展

肠道菌群影响畜禽生长发育以及相关多个重要经济性状。就多种饲料添加剂调节畜禽肠道菌群及其生长性状的研究进展进行综述。从生物学机制出发,介绍了饲料添加剂对畜禽肠道菌群及其生长性状的影响和菌群移植影响宿主生长性状的研究进展,总结了通过饲料添加剂影响畜禽肠道菌群、改善畜禽生长性能的应用实践。     

辽东枫叶变色气象条件分析和气象指数研究

为了研究气象要素对枫叶变红时间、程度的影响并对赏枫的天气适宜度做出准确预报,本文利用2014—2017年辽东本溪、本溪县、桓仁3个国家级气象站9—10月的气象资料和关门山公园、老边沟景区、中华枫叶之路、枫林谷等16个监测区域65个监测样点枫叶物候观测资料,分析影响枫叶变色的气象条件及最佳观赏期特点,确定枫红气象指数的计算方法和等级划分。结果表明:（1）辽东山区进入初红状态平均时间是9月26日,进入正红状态平均时间是10月8日;枫叶进入初红状态的时间较初霜日有明显提前,进入斑红状态的时间和初霜日对应较好,有70%以上的样点在初霜日前1天到后1天之间进入斑红状态。（2）气温对枫叶变色的影响显著,在枫叶开始变色阶段,日平均温度、日最高气温和日最低气温越低,枫叶变色率越高;降水对枫叶变色也有一定的影响,7—9月降雨较多的年份,枫叶进入最佳观赏状态时间较晚,但枫叶观赏期较长。（3）每年9月16日之后,日平均气温在12~18℃时,枫叶进入初红状态;日平均气温在5~15℃时,枫叶进入正红状态;日最低气温低于10℃,并累积超过3天,进入初红状态;日最低气温低于6℃,并累积超过3天进入正红状态;气温日较差大于15℃,并积累超过3天,开始进入初红状态。（4）枫叶变色前都会经历一次明显的降温,初红状态出现在降温后的第1天或第2天,斑红状态出现在降温后的第3天或第4天。（5）根据分析结果建立枫红气象指数,划分为4级标准,分别为一级适宜、二级较适宜、三级不太适宜、四级不适宜,分级表征枫红的观赏适宜度,为游客赏枫提供参考。     

Evaluating light trap efficiency by application of mesh to prevent inter- and intra-specific in situ predation on fish larvae and juveniles

Amongst passive collecting gear types, light traps have been used extensively to sample the larvae and juveniles of fish in both marine and freshwater environments, and especially so in structurally complex habitats. Although a number of modifications have been proposed to increase efficiency, no account has hitherto been made of the possible loss of trapped larvae and juveniles as a result of within-trap predation by piscivorous fish. To address this issue, we evaluated the efficiency of modified light traps by the addition of mesh (3 mm knot-to-knot wrapped around the entrance chambers), by combining results from a long-term monitoring study with those from a designed field experiment. Abundance of larvae and juveniles collected during the monitoring program was higher in the years following mesh application (hence, beyond monthly variation), and this was supported by the experiment. Based on the latter, light/mesh traps consistently caught only larvae/juveniles, hence excluding adults; whereas the opposite was true of the light/no-mesh trap combination. Also, mesh/no-light traps did not capture any fish, unlike no-mesh/no-light traps, which sampled only adults. Our findings suggest that in situ predation on larvae and juveniles within light traps should not be overlooked. The occurrence of piscivorous and cannibalistic behaviour in Hypseleotris spp. is also discussed.     

Albacore (Thunnus alalunga) fishing ground in relation to oceanographic conditions in the western North Pacific Ocean using remotely sensed satellite data

Satellite‐based oceanographic data of sea surface temperature (SST), sea surface chlorophyll‐a concentration (SSC), and sea surface height anomaly (SSHA) together with catch data were used to investigate the relationship between albacore fishing ground and oceanographic conditions and also to predict potential habitats for albacore in the western North Pacific Ocean. Empirical cumulative distribution function and high catch data analyses were used to calculate preferred ranges of the three oceanographic conditions. Results indicate that highest catch per unit efforts (CPUEs) corresponded with areas of SST 18.5–21.5°C, SSC 0.2–0.4 mg m^?3, and SSHA ?5.0 to 32.2 cm during the winter in the period 1998–2000. We used these ranges to generate a simple prediction map for detecting potential fishing grounds. Statistically, to predict spatial patterns of potential albacore habitats, we applied a combined generalized additive model (GAM) / generalized linear model (GLM). To build our model, we first constructed a GAM as an exploratory tool to identify the functional relationships between the environmental variables and CPUE; we then made parameters out of these relationships using the GLM to generate a robust prediction tool. The areas of highest CPUEs predicted by the models were consistent with the potential habitats on the simple prediction map and observation data, suggesting that the dynamics of ocean eddies (November 1998 and 2000) and fronts (November 1999) may account for the spatial patterns of highest albacore catch rates predicted in the study area. The results also suggest that multispectrum satellite data can provide useful information to characterize and predict potential tuna habitats.     

Environmental and spatial effects on the distribution of blue marlin (Makaira nigricans) as inferred from data for longline fisheries in the Pacific Ocean

Blue marlin is distributed throughout tropical and temperate waters in the Pacific Ocean. However, the preference of this species for particular habitats may impact its vulnerability to being caught. The relationship between spatio‐temporal patterns of blue marlin abundance and environmental factors is examined using generalized additive models fitted to catch and effort data from longline fisheries. The presence of blue marlin, and the catch rate given presence, are modeled separately. Latitude, longitude, and sea‐surface temperature explain the greatest proportion of the deviance. Spatial distributions of relative density of blue marlin, based on combining the probability of presence and relative density given presence, indicate that there is seasonal variation in the distribution of blue marlin, and that the highest densities occur in the tropics. Seasonal patterns in the relative density of blue marlin appear to be related to shifts in SST. The distribution and relative abundance of blue marlin are sufficiently heterogeneous in space and time that the results of analyses of catch and effort data to identify ‘hotspots’ could be used as the basis for time‐area management to reduce the amount of blue marlin bycaught in longline fisheries.     

Using historical fisheries data to predict tuna distribution within the British Indian Ocean Territory Marine Protected Area,and implications for its management

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Effects of dietary Bergamot (Citrus bergamia) peel oil on growth,haematology and immune response of European sea bass (Dicentrarchus labrax) juveniles

The aim of the present study was to evaluate the effects of essential oil extracted from bergamot (Citrus bergamia) peel on growth performance and health status of European sea bass juveniles (5.10 + 0.05 g). Test diets supplemented with 0.0%, 0.5%, 1.0% and 2.0% bergamot peel oil (BPO₀, BPO_0.5, BPO₁ and BPO₂) were fed to experimental fish for 60 days. At the end of the experiment, the best growth performance was obtained in the BPO_0.5 and BPO₁ groups (p < .05). No significances were found for haematological parameters including red blood cell count, haematocrit and haemoglobin concentration at the end of the feeding experiment. There were significant differences between the total protein, cholesterol, alkaline phosphatase and glutamic oxaloacetic transaminase (p < .05) between the BPO0.5 and BPO1 supplemented groups and the control group with no BPO addition. The addition of BPO showed significant differences in immune parameters such as lysozyme activity, total myeloperoxidase content, superoxide dismutase and glutathione peroxidase activity between BPO₀ and BPO supplemented groups (p < .05). It might be concluded that dietary addition of 0.5%‐1% BPO could increase the growth performance and feed utilization with improved health status in sea bass juveniles.