Current issue

• 2011 Vol.1 No.7 Published:26 September 2011

  Study on Characteristics of Laccase from Eriobotrya japonica Pulp 2011, 1 (7):  1-5.  Abstract + ( 3202 )   PDF ( 1097KB )   ( 1710 ) Study on extraction and physical-chemical properties of Laccase (EC 1.10.3.2) from Eriobotrya japonica pulp, in order to establish the foundation for discussion on flesh woodiness mechanism of laccase in loquat fruits under low temperature storage. Laccase in Eriobotrya japonica Lindl. ‘Jiefangzhong’ was extracted and purified by (NH4)2SO4 salting out, dialysis and DEAE-cellulose column chromatography. The influences of different temperature, pH, substrate, inhibitor and metal ions on the activity of laccase were studied. The changes of pH were determined in loquat fruits during storage. The results showed that the optimal temperature of laccase was 4.4, and optimal pH was 45℃. The enzyme activity was stable in the pH range of 3.2-4.4. The laccase activity was increased by the addition of Cu2+ and K+, while it was inhibited by the addition of Ag+, Fe2+ and Fe3+. Both EDTA and L-cysteine had an inhibitory effect on the laccase activity, and L-cysteine was the strongest one. The Km constants based on the substrate of 2,2-azobis(3-ethylbenzothiazole-6-sulfonaic acid) (ABTS) was 0.00512 mol/L .

  Effect of Different Top-dressing Times on Photosynthetic Physiological Properties and Yield of Peanut 2011, 1 (7):  6-10.  Abstract + ( 2142 )   PDF ( 967KB )   ( 2537 ) In order to show the inference of fertilizer stages on photosynthesis and yield about peanut planting , Qinghua5 was used to test the best stage to fertilizer . Under field conditions , we explore the change of LAI, SPAD, Photosynthetic rate, Yield components based on fertilizer stages. The results suggested that fertilizer on Flower-peg forming stage can improve LAI significantly and the days of LAI>3 is more than 30; the SPAD of available leaves can maintain higher level, the photosynthetic rate of available leave can improve significantly, the pod numbers of single plant increase 3.5, pod weight increase 9.7%, that reduce to the improvement of 9.33% of economic yield. Fertilizer on Flower-peg forming stage can be a technology on increasing the yield of peanut on planting.

  Analysis of Monitoring Result of Rural Rodents in Guizhou Province from 1984 to 2010 2011, 1 (7):  11-17.  Abstract + ( 1701 )   PDF ( 1188KB )   ( 1609 ) In order to find out the rodent population composition and the changes of population dynamics and provide scientific basis for forecast and prevention of population, we analyzed the monitoring of rural rodents in 30 counties (cities, districts) in Guizhou Province from 1984 to 2010. The results indicated that rodents in Guizhou Province belong to 2 orders (Rodentia, Insectivora) 3 Division (Muridae, Cricetidae, Soricidae) and 18 species, mainly in the Muridae, 77.78% of the total number. Oriental species is absolutely dominant species in fauna composition, 66.67% of the total number. In residential area, Rattus norvegicus and Rattus tanezumi are dominant species, respectively, 51.26% and 29.16% of the total number. Mus musculus is common species, 16.80% of the total number. In agricultural areas, Apodemus agrarius is dominant species (paddyfield, dryland), 62.57% of the total number. Rattus norvegicus and Rattus tanezumi are common species, respectively, 12.29% and 14.73% of the total number. They are also dominant species of agricultural rodents in some areas. Apodemus chevrieri is dominant species in the northwestern parts of Guizhou Province. The focal monitoring species in Guizhou Province are Apodemus agrarius, Apodemus agrarius, Rattus norvegicus, Rattus tanezumi and Mus musculus. The number of rodents in residential areas is significantly higher than that in agricultural. Population dynamics showed a downward trend and varies significantly in different year, different period, different months and different seasons. According years forecast and control of agricultural rodents in Guizhou Province, we cleared the technical route of monitoring and integrated control of agricultural rodents and brought up a set of practical monitoring technology and integrated control matching technology of agricultural rodents.

  Isolation and Identification of Antagonistic Actinomyces LY18 Against Phytophthora parasitica var. nicotianae 2011, 1 (7):  18-22.  Abstract + ( 1610 )   PDF ( 4566KB )   ( 1463 ) In order to screen antagonists against Phytophthora parasitica var. nicotianae, the plate-confrontation method was used. Actinomycetes strain LY18 isolated from soil samples around healthy tobacco individuals’ roots in tobacco field which broke out tobacco black shank, showed well inhibitory activity to Phytophthora parasitica var. nicotianae. The aseptic filtrate of LY18 mixed into medium plate against Phytophthora parasitica var. nicotianae by reducing mycelium growth 70%. The mycelium of Phytophthora parasitica var. nicotianae in plate added aseptic filtrate of LY18 was degradation by SEM observed. LY18 was identified as Streptomyces rajshahiensis according to its morphology, culture characteristic, chemotaxonomic tests and 16S rDNA analisis.

  The Overview of Eco-agriculture with High Efficiency 2011, 1 (7):  23-33.  Abstract + ( 2985 )   PDF ( 1084KB )   ( 2709 ) From the purpose, content, characteristics, principles, patterns and technology of eco-agriculture with high efficiency, the theory and practice of eco-agriculture with high efficiency had been analyzed generally and systematically. The results showed that: (1) the concept of eco-agriculture with high efficiency was purposed in 1991 in China; (2) Eco-agriculture with high efficiency emphasized on the ‘high efficiency’, ‘ecological’ and ‘combine’; (3) Eco-agriculture with high efficiency had a lot of characteristics with more organisms, good environment, good structure, strong function, good quality, high efficiency, low-carbon emissions, and sustainable development; (4) The principle of the eco-agriculture with high efficiency with the increasing of output and efficiency lay with full use of land, three-dimensional use of sunlight energy, excess use of seasons, multi-layer use of moisture, high efficient use of fertilizer, symbiosis and complementation among organisms, ecological disaster-reduction, and recycling use of agricultural resource; (5) The typical modes of eco-agriculture with high efficiency were these: the three-dimensional use of agricultural resource, the type of biological symbiosis among organisms, the conjunction type of conglomerate, the type of the industrial extension, the technology-driven type, the type of the environmental improvement, the resource recycling type, and the type of the leisure travel; (6) The key technologies of eco-agriculture with high efficiency were these: the resources saving technology, the irrigation and fertilization regulating technology, the biological soil improving technology, the disaster prevention and reduction technology, the resource comprehensive utilization technology, the soil and water conservation technology, structural adjustment technology, the new energy development technology, the valley harnessing technology, and the current modern new high technology.

  The Effect of Consecutive 3-Year Application of Soil Decontaminant Ronbao in the Bamboo Forest on the Yield of Bamboo Shoots and Soil Property 2011, 1 (7):  34-38.  Abstract + ( 1454 )   PDF ( 1026KB )   ( 1689 ) In order to increase the yield of bamboo shoots and control soil obstacle factors happening in the bamboo forest (Phyllostachys praecox f. prevelnalis), the comparative experiment of soil decontaminant Ronbao had been conducted for consecutive 3 years. The results of experiment showed that: the yield of bamboo shoots at the application rate of 600 kg/hm2 plus 45% compound fertilizer at 900 kg/hm2 increased averagely by 30.1% in comparison with that under CK without the application of soil decontaminant. After the application of soil decontaminant, soil pH values were significantly higher their controls (P<0.05) while the contents of soil exchange acidity were significantly lower than their controls (P<0.05). No bacteria strains were observed in the decontaminant-treated soil whereas 18 soil bacteria strains were found in the control. This showed that the soil decontaminant had a sterilization effect, resulting in mitigating the soil-borne disease and increasing the survival rate of bamboos.

  Determination of the Chloride Content in Soil by Ion Chromatography 2011, 1 (7):  39-42.  Abstract + ( 1610 )   PDF ( 1026KB )   ( 1767 ) This paper introduced a method for analyzing the chloridion content in soil by ion chromatography with water as the extracting agent. Soil samples could be extracted by deionized water in a water/soil ratio (v/w) as 10:1 with ultrasonic treatment for 30 min. Then the chloridion was seperated by anion exchange chromatography with KOH as elution buffer and detected by electrical conductivity detector. Results of accuracy and exactitude experiments showed this method could be used to treat various soil samples with different characteristics.

  Effects of Waxing on Storage of ‘Long Leaf Orange’ Citrus Fruits 2011, 1 (7):  43-45.  Abstract + ( 1966 )   PDF ( 1078KB )   ( 1584 ) In order to measure storage effect of orange treated with different wax, the author analyzed the physical and chemical index of a variety of wax (Decco Fruitshine 402F wax, FMC890 wax, own wax) on ‘long leaf orange’ at room temperature. The results showed that waxing could obviously improve the brightness of fruits, decrease the rate of weight loss. After storage of 27 days, there was no obvious difference in content of sugar between fruits treated with waxes and the control, while the titratable acid content of treated fruits were higher than the control. The titratable acid content declined gradually. The brightness and the rate of weight loss of fruits treated with own wax were significantly lower than those treated with Fruitshine 402F wax and FMC890 wax.

  The Use of Eugenol as an Anaesthetic for the Australian Longfinned Eel, Anguilla reinhardtii (Steindachner) 2011, 1 (7):  46-50.  Abstract + ( 4057 )   Anaesthesia is important in handling large river eels during procedures such as measuring, tagging and surgery. Therefore, the use of eugenol as an anaesthetic for the Australian longfinned eel, Anguilla reinhardtii (Steindachner) was investigated with a range of concentrations (10-120 mg/L). 20-120 mg/L of eugenol was found to be safe and effective (P <0.05), which could induce anaesthesia in less than 10 min, and recover after anaesthesia also in less than 10 min with a recovery rate of 100%. The difference of induction times and recovery times among 40, 60, 80 and 100 mg/L was not statistically significant, but with and among other groups was significant (P <0.05). Interestingly, average induction times did not always drop as the concentration increased. The induction time decreased from 312.88 s to 252.25 s when the concentration increased from 20 mg/L to 30 mg/L, while increased greatly to 582.00 s when attained 40 mg/L. Between 40-120 mg/L, induction times were inversely correlated with concentrations (r =-0.84, P <0.05), and dropped again in general along with the increase of concentration. Mean recovery time was the shortest for 20 and 30 mg/L, and shorter for 120 mg/L, and showed correlations of a certain degree both with anaesthetic concentration and induction time (r = 0.52, P <0.05). In conclusion, eugenol is a safe and effective anaesthetic for the Australian longfinned eel. 20-30 mg/L of anaesthetic concentration which can induce anaesthesia in 4-5 min in average and recover after anaesthesia in 4-7 min is recommended.

  The Effects of Starvation Stress on the Antioxidant Parameter of Tilapia (Oreochromis spp.) fed with Sophora Flavonoids 2011, 1 (7):  51-55.  Abstract + ( 1478 )   PDF ( 1021KB )   ( 1585 ) In order to study the effects of starvation stress on the antioxidant ability of tilapia that had been fed with Sophora flavonoids (SF), 400 fish were divided into 5 groups with 4 replicates in each group. Tilapia with average weight of (11.52±2.85) g per tail, were exposed to dietary SF at concentrations of 0, 200, 400, 800 and 1600 mg/kg for 7 weeks, then were starved for 1 d, 8 d, 15 d to measure the content of malonaldehyde (MDA), the total antioxidation capacity (T-AOC), and the activity of superoxide dismutase (SOD) and catalase (CAT) of the tilapia’s hepatopancreas. The results showed that 200 to 1600 mg/kg dietary SF significantly decreased the content of the MDA and the activity of CAT of the experimental groups (P＜0.01), and significantly increased the level of the T-AOC (P＜0.01) and the activity of the SOD (P＜0.05)of the experimental group. The antioxidant ability of tilapia increased with the increase of the level of dietary SF, and the group fed with 1600 mg/kg SF was the best. The results indicated that the ability of the oxidation resistance under starvation stress could be enhanced by adding SF in feed of tilapia.

  Practice “Five-ladder” Practical Teaching System to Cultivate Innovative Undertaking Talents in Agricultural Specialties 2011, 1 (7):  56-60.  Abstract + ( 1483 )   PDF ( 1045KB )   ( 1750 ) To incubate the innovative undertaking talents, the reforms in 9 agricultural specialties were conducted and “five-ladder” practical teaching system, i.e., experimental ability cultivation→ production practicality cognition→ specialty skill training→ innovative spirit incubation→ specialty comprehensive practice, were formed and enforced. In details, the experimental abilities of the undergraduates were cultivated by the curricularization of experimental teaching. The undergraduates recognized the production procedures by productive practices. The undergraduates’ specialty skills were enhanced through kinds of training. The undergraduates’ innovative spirits were shaped by scientific research's stimuli upon teaching quality. The graduates were competent for their positions very quick. All in all, by 5 years of practice of the “five-ladder” practical teaching system, the teachers’ integrative abilities for all-around development of the innovative students were promoted and several teaching reform achievements were come out as well as the undergraduates’ innovative spirits were reform achievements were come out as well as the undergraduates’ innovative spirits were incubated, thus the graduates’ abilities of innovative undertaking and social competences were significantly improved.

  The Development of China's Urban Modernistic Agriculture Evaluation Research 2011, 1 (7):  61-66.  Abstract + ( 1754 )   PDF ( 2677KB )   ( 1413 ) In this paper, Concept and basic connotation of urban modernistic agriculture were summarized, and establish the evaluation index system of urban modernistic agriculture. Use the principal component projection method six cities of China urban agriculture development was evaluated, calculating the six cities of urban modernistic agriculture sorting and urban modernistic agriculture four points sorting. Will quantitative analysis results and urban modernistic agriculture development, and points out that, combined with the urban economy was urban modernistic agriculture foundation, urban modernistic agriculture production function must be combined with city resources characteristics, urban modernistic agriculture ecological function remains to be strengthened.