夹竹桃花挥发油的GC-MS分析及β-葡萄糖苷酶对夹竹桃花的增香和豚鼠离体子宫平滑肌的作用

目的:建立夹竹桃花挥发油GC-MS的色谱分离鉴定方法,分析夹竹桃花挥发油的化学成分和对豚鼠离体子宫平滑肌的作用。方法:采用挥发油提取器提取夹竹桃花挥发油,以GC-MS法进行分析鉴定,建立了豚鼠离体子宫模型。结果:分别从无酶和有酶的夹竹桃花挥发油提取物中确证了58和57个化合物,挥发油对豚鼠离体子宫平滑肌有收缩作用。结论:对夹竹桃的挥发油化学成分进行了比较分析结果表明,β-葡萄糖苷酶对夹竹桃花有较弱增香作用,也能增加豚鼠离体子宫平滑肌收缩。     

Sodium alginate supplementation modulates gut microbiota,health parameters,growth performance and growth‐related gene expression in Malaysian Mahseer Tor tambroides

This study investigated the effects of sodium alginate supplementation on gut microbiota composition, health parameters, growth performances and growth‐related gene expression of Malaysian mahseer. Five test diets were formulated by supplementing 0%, 0.1%, 0.2%, 0.4% and 0.8% sodium alginate. Triplicate groups of juvenile Tor tambroides (2.19 ± 0.05 g) were stocked in 15 aquaria (20 individuals per aquarium) and fed at 3.0% body weight per day for 60 days. PCoA and UPGMA analysis showed that gut bacterial community were more convergence in higher sodium alginate‐supplemented diets. The percentage of Porphyromonadaceae, Bacteroides, Plesiomonas and Shewanella were substantially higher and Aeromonas, Entomoplasmatales and Prevotellaceae were drastically lower in higher sodium alginate (0.2%–0.8%) diets. Sodium alginate supplementation (≥0.2%) significantly improved the haematocrit value and respiratory burst activity of T. tambroides. Growth performances and feed utilization were significantly higher in 0.2%–0.4% sodium alginate‐supplemented diets. The increased growth rate of T. tambroides was governed by both hyperplastic and hypertrophic muscle growth. Real‐time PCR data demonstrated that most of the growth‐related genes were significantly upregulated in 0.2%–0.4% sodium alginate‐supplemented diet. Finally, it can be concluded that sodium alginate should be supplemented at 2 g/kg in practical fish feed formulation.     

阿勒泰地区土地类型与农业自然分区

阿勒泰地区位于北纬44°59′-49°11′和东经85°32′-91°01′,区内分布有高山、丘陵、河谷、平原、沙漠、戈壁和湖泊,土地面积为17750万亩。对该区土地类型进行研究,有助于认识影响土地分异的因素和探讨农业自然分区,为合理利用土地资源,发展农、林、牧业生产提供科学依据。     

GS洛旱2号适宜生态类型区灰色布局分析

为了确定GS洛旱2号适宜推广种植区域,采用作物品种灰色布局原理与方法,对其在黄淮冬麦区的适宜生态类型区进行了研究,为大面积推广提供科学依据,并分析了品种灰色布局原理与方法的可行性。结果表明,洛旱2号适宜推广种植的区域为以宾州、长武、鹤壁、临沂、洛阳、嵩县、渭南、郑州为代表的生态类型区。作物品种灰色布局原理与方法改善了传统品种布局仅考虑产量因素的局限性,在指导大区域品种布局时更宜适用。     

红花槭扦插生根特性和解剖学研究

以红花槭‘十月光辉’1年生带顶芽、1年生无顶芽和2年生硬枝为插穗,选用M1(河沙与珍珠岩的体积比为1∶1)、M2(河沙与蛭石的体积比为1∶1)、M3(珍珠岩与蛭石的体积比为1∶1)和M4(河沙、珍珠岩、蛭石的体积比为1∶1∶1)4种不同的扦插基质,施加不同质量浓度的吲哚丁酸(IBA)和萘乙酸(NAA)进行扦插试验,研究插穗类型、基质种类和外源激素对红花槭扦插生根的影响,并对扦插过程中不定根发育形成过程进行组织学观察。结果表明:M4基质在生根率(69.44%)、平均生根数量(14.31条)和平均根长(5.40cm)方面均表现最优,为适宜的扦插基质;1年生插穗生根率和平均根数均高于2年生插穗的,平均根长低于2年生插穗的;1年生带顶芽与1年生无顶芽插穗的扦插生根率差异不显著(P0.05);500mg/L IBA+500mg/LNAA处理效果最好,生根率达75.56%,平均生根数量为15.68条,平均根长为6.48 cm。红花槭属于诱生根原基多位点发生类型,其不定根起源于木射线与维管形成层交叉区域和韧皮部薄壁组织。     

复合酶提取法对浒苔(Enteromorpha sp.)膳食纤维吸附能力的影响

针对丰富的浒苔资源还未得到有效利用的现状,以浒苔为原料,采用复合酶提取法制备浒苔膳食纤维。浒苔在55℃、pH=7.7的条件下,由不同比例的蛋白酶和纤维素酶(5:1、10:1、15:1、20:1和25:1)配制的复合酶进行酶解,提取膳食纤维,测定不同提取条件得到的浒苔膳食纤维在模拟体内的环境下(pH=2.0和pH=7.0)吸附葡萄糖、胆固醇和亚硝酸盐的能力。结果显示,随着复合酶中蛋白酶比例的升高,膳食纤维对葡萄糖和胆固醇的吸附能力先增强后减弱。在蛋白酶∶纤维素酶的比例为10:1时,膳食纤维对葡萄糖的最大吸附值为20.03 mg/g;在蛋白酶∶纤维素酶比例为15:1时,膳食纤维对胆固醇的最大吸附值为21.93 mg/g。而浒苔膳食纤维吸附亚硝酸的能力则随着复合酶中蛋白酶比例的升高而逐渐增强,在蛋白酶∶纤维素酶比例为25:1时,浒苔膳食纤维对亚硝酸盐达到最大吸附值29.25 µmol/g。在人工肠液中(pH=7.0),膳食纤维对胆固醇的吸附能力较强;在人工胃液中(pH=2.0),膳食纤维对亚硝酸盐的吸附能力较强;膳食纤维对葡萄糖的吸附能力在人工肠、胃液中无显著差异(P>0.05)。推测膳食纤维对亚硝酸盐的吸附主要发生在胃部,对胆固醇的吸附主要发生在肠部,而膳食纤维对葡萄糖的吸附在胃部和肠部同时进行,是一个持续的吸附过程。     

不同类型玉米耐密性分析及对主要性状的影响

通过对不同穗型品种耐密性及密度对主要农艺性状影响的研究表明,密度对株高、倒伏的影响为大穗型品种中穗型品种小穗型品种;穗长、穗行数受密度影响最大的为大穗型品种,其次为中穗型品种;行粒数对密度的响应表现为中穗型品种小穗型品种大穗型品种;先玉335的适宜密度9.00万~9.75万hm-2,正大12为7.50万~8.25万hm-2,宁玉12为6.00万~6.75万hm-2。     

蓝圆鲹肌肉中营养成分分析与评价

为了测定蓝圆鲹(Decapterus maruadsi)肌肉中的营养成分,并对其营养价值进行系统的分析及合理的评价,采用国家标准生化测定方法检测蓝圆鲹肌肉中的水分、粗蛋白质、粗脂肪、粗灰分、氨基酸、脂肪酸及矿物质。结果显示,蓝圆鲹肌肉中水分含量为75.00%,粗蛋白质、粗脂肪及粗灰分的干重含量分别为79.52%、9.88%和4.16%;共检出18种氨基酸,总含量为75.24%(干重),必需氨基酸占氨基酸总含量的30.08%,谷氨酸含量最高(11.40%),主要的限制氨基酸是色氨酸和缬氨酸,必需氨基酸指数EAAI为83.32;共检出17种脂肪酸,棕榈酸含量最高(2.60%),EPA+DHA含量为2.20%;富含磷(P)、钾(K)、钙(Ca)、钠(Na)、镁(Mg)等矿物质元素,常量元素中磷的含量最高(2 193.99 mg/kg),微量元素中铁的含量最高(22.25 mg/kg)。研究表明,蓝圆鲹是高蛋白低脂肪、营养价值及经济价值均较高的优质海洋经济鱼类,具有较好的综合开发利用价值。     

Use of geographical information systems as a tool for predicting fish yield in tropical reservoirs: case study on Sri Lankan reservoirs

Use of geographical information systems (GIS) in inland fisheries has hitherto been essentially restricted to site evaluation for aquaculture development and assessment of limnological changes in time and space in individual water bodies. The present GIS study was conducted on the land-use pattern of the catchments of nine reservoirs in Sri Lanka, for which detailed fishery data, viz. yield, fishing intensity, landing size of major constituent species, together with selected limnological data such as conductivity and chlorophyll- a , were available. Potential statistical relationships (linear, curvilinear, exponential and second-order polynomial) of fish yield ( FY , in kg ha⁻¹ yr⁻¹) to different land-use patterns, such as forest cover ( FC , in km²) and shrub-land ( SL , in km²), either singly, or in combination, and/or the ratio of each land type to reservoir area ( RA in km²) and reservoir capacity ( RC in km³), were explored. Highly significant relationships were evident between FY to the ratio of SL and/or FC + SL to RA and/or RC . Similarly, the above land-use types to RA and RC ratios were significantly related to limnological features of the reservoirs. The relationships of FY to various parameters obtained in this study were much better correlated than those relationships of FY to limnological and biological parameters used in yield prediction in tropical and temperate lacustrine waters previously.     

Characterization of the morphological,physical, and mechanical properties of seven nonwood plant fiber bundles

The morphological, physical, and mechanical properties of the nonwood plant fiber bundles of ramie, pineapple, sansevieria, kenaf, abaca, sisal, and coconut fiber bundles were investigated. All fibers except those of coconut fiber had noncircular cross-sectional shapes. The crosssectional area of the fiber bundles was evaluated by an improved method using scanning electron microscope images. The coefficient factor defined as the ratio of the cross-sectional area determined by diameter measurement, to the cross-sectional area determined by image analysis was between 0.92 and 0.96 for all fibers. This indicated that the area determined by diameter measurement was available. The densities of the fiber bundles decreased with increasing diameters. The diameters of each fiber species had small variation of around 3.4%-9.8% within a specimen. The tensile strength and Young’s modulus of ramie, pineapple, and sansevieria fiber bundles showed excellent values in comparison with the other fibers. The tensile strength and Young’s modulus showed a decreasing trend with increasing diameter of fiber bundles.