不同干燥方式对牛肉干物性特性的影响

为了探究中红外-热风组合(combined mid-infrared and hot air,CMIHA)干燥对牛肉干物性特性的影响,该文研究了CMIHA干燥工艺和热风(hot air,HA)干燥工艺对牛肉干干燥过程中色泽与质构特性的影响。通过分析牛肉干在2种干燥过程中亮度值、红度值、黄度值的变化,结合肌红蛋白、高铁肌红蛋白、氧合肌红蛋白及血红素铁的含量变化,研究干燥工艺对牛肉干色泽的影响;通过测定干燥过程中牛肉干嫩度和质构分析(texture profile analysis,TPA)的变化,并基于扫描电镜(scanning electron microscopy,SEM)、透射电镜(transmission electron microscope,TEM)以及核磁成像系统(magnetic resonance imaging,MRI)研究干燥工艺对牛肉干微观结构及氢质子密度的影响,分析干燥工艺对牛肉干质构的影响。结果表明:与HA干燥相比,CMIHA干燥后期能够显著(P<0.05)改善牛肉干的色泽,提高牛肉干的嫩度,增加牛肉干的弹性和咀嚼性;另外,与HA干燥相比,CMIHA干燥能够降低肌红蛋白的氧化,增加氧合肌红蛋白、肌红蛋白和血红素铁的含量,赋予牛肉干较好的色泽;SEM与TEM观察结果表明,牛肉在干燥过程中,肌肉的微观结构均发生一定的收缩,但与HA干燥相比,CMIHA干燥的牛肉干肌肉微观结构收缩程度较轻,同时微观结构保持较好;MRI观察结果表明,与HA干燥相比,牛肉干在CMIHA干燥过程中,内外水分分布较均匀,且收缩程度较轻。与生产中常规使用的HA干燥相比,CMIHA干燥能够降低肌红蛋白的氧化和肌肉微观结构的收缩,增加内外水分子分布的均一性,从而改善牛肉干的色泽和质构,提高牛肉干的物性特性。研究结果为CMIHA干燥在牛肉干方面的应用提供理论依据与技术参考。

基于主成分综合评价法对植物基杏仁酸奶配方的优化及其物性学特性的表征

本研究旨在优化植物基杏仁酸奶配方,以提高其品质、增强其储藏稳定性能。研究以甜杏仁为主要原料,添加乳化剂、增浆剂等常规酸奶稳定剂,通过乳酸发酵制成植物基杏仁酸奶。采用主成分综合评价分析和响应面优化法确定最佳酸奶稳定剂配方,并对其物性学特性进行研究表征。研究结果表明:最佳的植物基杏仁酸奶配方为:酒石酸单双甘油酯添加量0.4%、羟丙基二淀粉磷酸酯添加量2.0%、谷氨酰胺转氨酶添加量0.1%,综合评分为0.990,通过响应面验证后的植物酸奶综合评分与预测结果接近。经调配的植物基酸奶品质及总接受程度显著提升,复配植物基杏仁酸奶(MPBAY)微观颗粒更加饱满,乳脂分配更加均匀,质地更加醇厚。此研究为植物基酸奶的开发及植物蛋白胶凝聚集体系研究,提供了一定研究思路和科学理论价值参考。

苗圃杂草及除草剂的生物学特性分析

苗圃杂草种类繁多,不同种类的杂草和苗木在苗圃中共生,杂草的防治直接影响着苗圃植株的成长。合理选用除草剂是苗圃除草的关键,因此,分析除草剂的生物学特性,为除草剂的施用提供客观指导,具有现实的理论意义和实践价值。

加热条件下鱼翅结构和物性学参数变化

研究了鱼翅在不同加热时间(1、2、3、4 h)条件下组织构造及其物性学参数(凝胶强度、最大破断应变、剪切应力、破断强度)变化,并测定了胶原蛋白含量。通过扫描电子显微镜镜观察鱼翅的组织构造,采用质构仪测定其物性特性。结果表明,随着加热时间的延长,鱼翅的物性学参数变化显著,总体呈减小趋势。加热3 h后即可达到鱼翅较好质构。

葛氏鲈塘鳢生物学特性与养殖前景展望

对葛氏鲈塘鳢的形态特征、生活习性、繁殖与生长主要生物性特性进行了介绍,并分析了葛氏鲈塘鳢的养殖前景,以期为开发利用葛氏鲈塘鳢资源提供参考。

Genetic Study on JS399-19 Resistance in Hyphal Fusion of Fusarium graminearum by Using Nitrate Nonutilizing Mutants as Genetic Markers

Twenty-two nitrate nonutilizing （nit） mutants were recovered from five wild-type isolates of Fusarium graminearum and fifty nit mutants were recovered from three JS399-19-resistant mutants of F. graminearum cultured on MMC medium. Some biological properties were compared between nit mutants and their parental isolates. The results showed that there were no significant differences in growth rate, cultural characters or pathogenicity between JS399-19-resistant nit mutants and their parental isolates. But the conidial production and the sexual reproduction ability changed to some extent. There was no cross resistance toward chlorate and JS399-19 in F. graminearum and the resistance could be stable through 20-time subcultures. Therefore, the nit could be used as a genetic marker for studying the genetics of JS399-19 resistance in E graminearum, which was used to study JS399-19 resistance transferability in hyphal fusion. Resistance in JS399-19 could not be transferred by hyphal fusion or could be transferred with low chance between two compatible isolates, which would delay the development of JS399-19 resistance in the field.

Isolation and Biological Characteristics of Bacteriophage of an Antibiotic-resistant Escherchia coli Strain

In this study, bacteriophage of an antibiotic-resistant Escherchia coil strain isolated from feces of chicken was isolated. Its host range was determined by the method of spotting sample on monolayer agar, and its lysis titer, optimal multiplicity of infection （MOI）, temperature tolerance and pH tolerance were determined by the double-layer agar plate method. The results showed that the bacteriophage had a broad host range. The biological assay demonstrated that two strains of E. coil were fully lysed and one strain of E. coil was weakly lysed by the bacteriophage. The lysis titer and MOI of the bacteriophage were 1.20×10^8 PFU/ml and 1, respec- tively. Under the optimum temperature of 40℃, the Jysis titer of the bacteriophage reached 8.90×10^9 PFU/ml; however, the bacteriophage lost its infectivity at the tem- perature of 80℃. In the pH range of 5-11, the lysis titer of the bacteriophage ranged from10^6 to 10^9 PFU/mI. Under the condition of pH 4 and 12, the bacterio- phage was invalid.

Isolation and Identification of Colletotrichum gloeosporioides in Pears and Its Biological Characteristics

[Objective] This study aimed to explore the biological characteristics of Col etotrichum gloeosporioides in pears. [Method] Twenty-five C. gloeosporioides strains were isolated and identified from the diseased samples. Their pathogenicity was identified by inoculating the surface of punctured pears with fungal discs. The effects of different temperatures, pH values, carbon sources and nitrogen sources on the growth of C. gloeosporioides mycelia were explored by incubating fungal discs on the center of plates. [Result] Among the twenty-five C. gloeosporioides strains, three had strong pathogenicity, and eighteen had intermediate pathogenicity, and four strains had weak pathogenicity. Those highly-pathogenic strains had darker colonies, with dense mycelia, whereas those lowly-pathogenic ones had white colonies, with sparse mycelia. Those with fast-growing colonies showed strong pathogenicity, while those with slowly-growing colonies displayed weak pathogenicity. There was no relationship between conidia yield and pathogenicity. The optimum temperature for the growth of C. gloeosporioides mycelia was 25-30 ℃, and the optimum pH was 5.0-7.0. C. gloeosporioides could make use of various carbon sources （monosaccharide and disaccharide）, inorganic and organic nitrogen sources, and the optimal carbon source and nitrogen source were sucrose and beef extract, respectively. [Conclusion] Our study benefits further understanding of C. gloeospori-oides and helps to control pear anthracnose more effectively.

Biological Characteristics and Pathogenicities of Shewanella algae and Shewanella abalone from Babylonia

[Objective] The biological characteristics and pathogenicities of Shewanella algae and Shewanella abalone from Babylonia were studied in this paper. [Method]The hemolytic bacteria were isolated from the hepatopancreas of Babylonia suffered from proboscis edema with blood agar plate. The dominant bacterial community in the ill Babylonia was identified by 16 S r DNA sequence analysis, and the bacterial cultural and biochemical characteristics and pathogenicities were studied. [Result]The Shewanella bacteria, including Shewanella algae and Shewanella abalone, are the dominant bacterial community in Babylonia suffered from proboscis edema.The colony characteristics of Shewanella algae in nutrient agar medium, TCBS agar medium and CHROMagar vibrio colored medium were similar to those of Shewanella abalone. Shewanella algae possessed β-hemolysis and Shewanella abalone possessed α-hemolysis in the blood agar plate. The biochemical reaction of Shewanella algae and Shewanella abalone was all of non-fermentation type. The results of artificial infection test showed that half lethal dose（LD50） of the test strains of Shewanella algae was 10-5.50/0.1 ml. The test strains of Shewanella algae have strong toxicity, and could cause mice and chickens to die of sepsis with mortality of100%. The mortality of Babylonia infected with Shewanella algae was 10%; while the survived Babylonia lost the ability of moving and intaking for a long time, but they were not suffered from proboscis edema. There was no death in mice or chicks infected with Shewanella abalone, but their livers and spleens were slightly hyperemic and swelling. There was also no death in Babylonia infected with Shewanella abalone, but their intaking and moving ability was lost for a short time.[Conclusion] Although Shewanella algae and Shewanella abalone were the dominant bacteria in Babylonia suffered from proboscis edema, they were not the main pathogenic bacteria for proboscis edema. Shewanella algae had strong pathogenicity to mice, chicks and Babylonia, while Shewanella abalone showed no marked pathogenicity to those experimental animals in this study.

药用植物吴茱萸无公害栽培技术初探

文章以贵州余庆县吴茱萸规范化种植的经验为出发点,整理总结出吴茱萸无公害栽培、采收与初加工技术及贮藏运输的要点。

Study on Biological Characteristics and Pupa's Cold Tolerance of Liriomyza sativae on Florists cineraria

In this study, Liriomyza sativaes was raised on Florist cinerarias in greenhouse with different temperatures at 15, 20, 25, 30 and 35 ℃, and their corresponding development duration of entire generation were 47.0, 25.0, 15.5, 12.5 and 12.0 d. The beginning growth temperatures of egg, larva, pupa and entire generation of Liriomyza sativae were 8.5, 9.8, 10.2 and 10.4 ℃, and their effective accumulated temperatures were 52.7, 75.8, 158.5 and 262.2 d ·℃, respectively. Liriomyza sativae had 7 generations on Florist cinerarias in Ningxia each year. However, it occurred in the whole year in greenhouse. The length of its development duration in greenhouse decreased in order from cucumber, Callestephus chinensis, Florist cinerarias to pea, but the eclosion rate of its pupa was in the eentrary order. Under the temperature of 10, 0, - 15 and 20 ℃ ,the longer the storage of pupa was,the higher the mortality rate would be. Liriomyza sativae couldn＇t survive in the winter in Ningxia Province in the natural environment.

城镇绿化带蚧壳虫发生危害及综合防治技术

闸述了蚧壳虫发生种类、寄主植物、被害症状和生物学特性，包括形态特征、生活习性、发生规律等，提出了综合防治方法：加强植物检疫和栽培管理，人工清除、药物涂干、药剂防治。

Relationship between Biological Characteristics of Beauveria bassiana (Bals.) Vuill and Pathogenicity to Bombyx mori L.

[Objective] This study was to investigate the relationship between biological characteristics of Beauveria bassiana （Bals.） Vuill and pathogenicity to Bombyx rnori L, with the aim to provide scientific basis for the control of white muscardine in Bombyx mori L. [Method] The strains isolated and purified from the 6 Beauveria bassiana biocontrol agents from all over the country and the 3 white muscardine silkworms collected from Guangxi provincial silkworm rearing areas were identified by the morphological observation and molecular biology technology. The pathogenicity of B. bassaina to silkworms was determined, and the biological characteristics such as growth diameter, sporulation and the extracellular protease activity of the different B. bassiana strains were compared. [Result] The isolated 9 strains were all B. bassaina （Bals.） Vuillemin, and all strains had high pathogenicity to silkworm, but with different pathogenicities. The growth diameter, sporulation and extracellular protease activity of different B. bassiana strains were also different, and showed correlation with the patheogenicity to silkworms. [Conclusion] B. bassiana spores production amount and exocellular protease activity had significant positive correlation with their pathogenicity to silkworm.

Antibacterial Activity of Bacillus subtilis and Properties of Protein Crude Extract

In order to get biological drugs with no resistance or toxic side effects and to reduce the use of antibiotics, a strain of Baci//us subtilis was isolated from animal intestine, and the isolate was identified by molecular biological method; in vitro an- tibacterial test of the isolate was performed using agar diffusion method; the optimal fermentation condition of the isoJate was screened by conventional culture method; the antibacterial crude protein of the isolate was extracted by saturated ammonium sulfate method; the physicochemical properties of antibacterial crude protein was de- tected by comparison method; The results showed that the isolate was B. subti/is, which had antibacterial effects on Staphy/ococcus aureus, streptococcus and swine erysipelas. The fermentation effect of the isolate was the best under the condition of temperature 30 ~C, pH 7, liquid volume 75 ml/250 ml, inoculation volume 20% and culture time 48 h. The antibacterial effect of the isolate was the best when extract- ed by 80% saturated ammonium sulfate. The antibacterial crude protein had strong resistance to heat and acid. Organic solvent and UV irradiation had some influences on antibacterial crude protein. Proteases had hydrolytic effects on antibacterial crude protein. The isolated B. subti/is can be used to prevent and control the diseases caused by S. aureus, streptococcus and swine erysipelas, and can regulate intesti- nal microecology by adding into expanded feeds.

Heterogeneity of Physico-Chemical Properties in Structured Soils and Its Consequences

Structured soils are characterized by the presence of inter- and intra-aggregate pore systems and aggregates, which show varying chemical, physical, and biological properties depending on the aggregate type and land use system. How far these aspects also affect the ion exchange processes and to what extent the interaction between the carbon distribution and kind of organic substances affect the internal soil strength as well as hydraulic properties like wettability are still under discussion. Thus, the objective of this research was to clarify the effect of soil aggregation on physical and chemical properties of structured soils at two scales: homogenized material and single aggregates. Data obtained by sequentially peeling off soil aggregates layers revealed gradients in the chemical composition from the aggregate surface to the aggregate core. In aggregates from long term untreated forest soils we found lower amounts of carbon in the external layer, while in arable soils the differentiation was not pronounced. However, soil aggregates originating from these sites exhibited a higher concentration of microbial activity in the outer aggregate layer and declined towards the interior. Furthermore, soil depth and the vegetation type affected the wettability. Aggregate strength depended on water suction and differences in tillage treatments.

Genetic Relationships Among Soluble Carbohydrates, Anthocyanins and Growth Characteristics in Leymus (Gramineae) Detected with Molecular Markers

Low-temperature soluble carbohydrate accumulations are commonly associated with anthocyanin coloration, attenuated growth and cold adaptation of cool-season grasses. The vrn-1 gene has potent effects on vernalization requirement, growth, and soluble carbohydrate accumulations of the winter-annual Triticeae species. Two hundred and four unmapped AFLP markers and genome-specific DNA markers genetically linked to the vrn-1 gene were used to detect QTL controlling soluble carbohydrate accumulations, anthocyanin coloration and growth characteristics in a segregating population derived from open pollinated Leymus cinereus x L. triticoides hybrids. These perennial Triticeae grasses are distinguished by adaptation and growth habit. As expected, positive trait correlations and pleiotropic gene effects were detected for soluble carbohydrate accumulations and anthocyanin coloration. Likewise, positive trait correlations and pleiotropic gene effects were detected for tillering, leaf development, leaf growth, regrowth and rhizome spread. However, soluble carbohydrate accumulations were not associated with attenuated growth. In fact, several DNA marker alleles, including one near vrn-Ns1, had positive effects on soluble leaf carbohydrate concentrations and low temperature growth. The corresponding DNA marker near vrn-Ns1 had more specific effects on tillering. We speculate that vrn-1 exerts quantitative effects on low-temperature soluble leaf carbohydrate accumulations and growth habit of the perennial Leymus. However, a number of other DNA markers displayed highly significant effects on soluble carbohydrate accumulations and various growth characteristics. Findings indicate that anthocyanin coloration may be a useful phenotypic marker for soluble carbohydrate accumulation. Although variation for soluble carbohydrates was not associated with attenuated growth in this population, this trait was under genetic control.

First Report of the Female of Thecobathra partinuda Fan,Jin et Li (Lepidoptera:Yponomeutidae)

The female of Thecobathra partinuda Fan,Jin et Li,2008 is described for the first time,with illustration of the genitalia.A comparison is made between the females of this species and T.kappa(Moriuti,1963).

Genetic Improvement and Biological Characteristic Analysis of Dwarf Abortive TypeJaponicaCMS Lines with Wide Compatibility

From the view of methodology for genetic improvement ofJaponicacytoplasmic male sterile(CMS) lines,we introduced the breeding process of the dwarf-abortive type(DA type)JaponicaCMS line Chunjiang 95A with wide compatibility,and further investigated the biological characteristics of the DA type Chunjiang 95A and its isonuclear alloplasmic CMS line Dian-I type Chunjiang 95A.The results show that DA type Chunjiang 95A is a japonicalinous CMS line and mainly typical abortive,which is better in fertility stability than stained abortive typeJaponica CMS lines.The DA type Chunjiang 95A is featured with high stigma exsertion,good flowering habit,high outcrossing rate and wide compatibility.Its recoverability differs from stained abortive typeJaponicaCMS lines.Moreover,we discussed genetic improvement of the typical abortive type JaponicaCMS lines and the application prospects of heterosis.

Effect of Organic Manure Application on Physical Properties and Humus Characteristics of Paddy Soil

Long-term field experiment was established in 1978 on a coastal paddy soil to determine the effect of applicationof pig manure, rice straw and chemical N fertilizer on the physical property and humus characteristics of soil . Resultsshowed that the porosity, the microstructural coefficient, the reactivities of organic C and N, the ΔlogK value, thedegree of oxidation stability, the contents of O-alkyl C and alkyl C, and the ratio of aliphatic C to aromatic C ofhumic acid from soils received organic manure increased, whereas, the ratio of < 10 μm to >10 μm ofmicroaggregates, the humification degree of humus, the degree of organo-mineral complexation, the number-averagemolecular weight, the C/ H ratio. the contents of carboxyl and aromatic C of HAs in them decreased. These resultsindicated that the application of organic manure not only improved the physical property of the paddy soil but alsomade the HA more aliphatic in structure and younger in origin.