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Assessing Soil Properties and Landforms in the Mai-Negus Catchment, Northern Ethiopia

Pedosphere 2016年第5期26卷 745-759页

作者： Gebreyesus Brhane TESFAHUNEGN Lulseged TAMENE Paul L.G.VLEK College of agriculture Aksum University-Shire Campus Center for Development research (ZEF) University of Bonn International Center for tropical agriculture (CIAT) Chitedze Agricultural Research Station

Soil degradation is a serious environmental problem in Ethiopia. However, little information is documented on indicators such as variations in soil properties across different landforms in a catchment. This study was aimed to assess soil properties and their changes across sites with different erosion statuses, and identify landscape positions that require prior management attention in the Mai-Negus catchment, northern Ethiopia. Three types of erosion-status sites(stable, eroding and aggrading) were identified using reconnaissance surveys, and then the corresponding soil samples were collected and analyzed. The major soil properties were significantly varied(P ≤ 0.05) among the three erosion-status sites. The highest soil p H, organic carbon, total nitrogen, cation exchange capacity, iron and zinc were recorded from the aggrading sites in the reservoir and valley landforms of the study catchment. A higher bulk density was generally recorded in the eroding sites, whereas a lower value was observed in the aggrading sites. The highest sand content was observed in the eroding sites of the mountain followed by the central ridge landform. The paired mean difference and the correlation matrix of most soil properties between the different erosion statuses also showed significant differences. About 95% of the erosionstatus sites were correctly classified by the discriminant function, indicating that the field survey-based classification was acceptable for decision making. On the basis of this study, suitable interventions should thus be introduced to the prioritized landforms, which are the mountain and central ridge, and eroding sites with severely degraded soil properties across the catchment.

关键词： aggrading site discriminant function eroding site erosion status landscape soil property variability stable site

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Reflection on the Construction of tropical and South Subtropical Agricultural Experimental station CATAS( Jiangmen)

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Asian Agricultural research 2014年第6期6卷 105-108页

作者： Shouxing WEI Xiulong CHEN Xindao QIN Guangzhou Experimental station CATAS tropical Crops Genetic Resources Institute CATAS National Engineering research Center of Key tropical Crops Key Open Laboratory of tropical Crops Genetic Resources Utilization by Ministry of agriculture

This paper introduces the origin and progress of tropical and South Subtropical Agricultural Comprehensive Experimental station( hereinafter referred to as experimental station) CATAS( Jiangmen),formulates the thought for construction of experimental station,analyzes the restrictive factors and puts forward corresponding countermeasures in order to provide reference for the decision- making and implementation of constructing the experimental station.

关键词： tropical and South Subtropical Agricultural Compre

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Awareness and adoption of land,soil and water conservation practices in the Chinyanja Triangle,Southern Africa

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International Soil and Water Conservation research 2017年第2期5卷 122-129页

作者： Nelson Mango Clifton Makate Lulseged Tamene Powell Mponela Gift Ndengu International Centre for tropical agriculture(CIAT) c/o Kawanda Research StationP.O.Box 6247KampalaUganda International Centre for tropical agriculture(CIAT) P.O.MP 228HarareZimbabwe International Centre for tropical agriculture(CIAT) c/o Chitedze Agricultural Research StationP.O.Box 158LilongweMalawi

The promotion of land,soil and water conservation measures has been a widespread development in sub-Saharan Africa in a bid to tackle degradation and improve *** a result,several gov-ernments have launched various campaigns on soil,land and water conservation *** aim of this study is to determine some of the factors that influence farmers'awareness(knowledge)and adoption of land,soil and water conservation *** for this study was collected from 312 households using a questionnaire survey in the Chinyanja Triangle of Southern *** study *** sampled from Tete province of Mozambique,central and southern regions of Malawi and eastern Province of *** used t-tests to classify adopters and non-adopters of soil,land and water con-servation measures and binomial logit models to identify the factors that infuence farmers'knowledge of conservation measures and adoption of land productivity *** results show that the household head's age,education,agricultural advice reception and farmer group membership are critical in raising *** the household head's age,education,agricultural advice reception,farmer group membership,pieces of land owned or used in production and land-to-man ratio influenced adoption *** study,therefore,concludes that in order to improve land productivity in the Chinyanja Triangle,there is a need to consider farmers'heterogeneity in terms of household head's age,level of education,extension services outreach,and socio-economic char *** suggests that governments'policies in the region should be aimed at improving farmers'level of education,extension delivery that will target the elderly and the youth,land ownership,credit access,and social capital such as group formation.

关键词： Conservation agriculture Awareness Adoption Chinyanja Triangle

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A new diterpene from the stems of Trigonostemon heterophyllus

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Chinese Journal of Natural Medicines 2014年第4期12卷 297-299页

作者： LI Yi-Xing ZUO Wen-Jian MEI Wen-Li CHEN Hui-Qin DAI Hao-Fu Key Laboratory of Biology and Genetic Resources of tropical Crops Ministry of Agriculture Institute of Tropical Bioscience and Biotechnology Chinese Academy of Tropical Agricultural Sciences Haikou Experimental station Chinese Academy of Tropical Agricultural Sciences

AIM: To investigate the chemical constituents in the stems of Trigonostemon heterophyllus. METHOD: The chemical constituents were isolated by column chromatography on silica gel, Rp-18, and Sephadex LH-20, and their structures were elucidated on the basis of spectroscopic analysis. RESULTS: Three compounds were isolated and identified as a new diterpene, trigonoheterene B(1), together with two known compounds, trigonostemone(2) and trigonochinene B(3). CONCLUSION: Compound 1 is new. Compounds 2 and 3 showed antibacterial activities.

关键词： Trigonostemon heterophyllus Trigonoheterene B Diterpene Antibacterial activities

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Removing ammonia from skim by air stripping with rotating packed bed

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Chinese Journal of Chemical Engineering 2019年第3期27卷 528-533页

作者： Hongxing Gui Xiuping Li Danzhou Investigation & Experiment station of tropical Crops Ministry of Agriculture School of Chemical and Engineering North University of China Shanxi Provincial Key Laboratory of Ultra-Gravity Chemical Engineering

Based on the effects of skim components on ammonium removal as well as the current processing technology, a new process-intensified technology of removing ammonia from skim by air stripping on rotating packed bed was proposed. The experiments were conducted on a wave-thread packed Rotating Packed Bed(RPB) under atmospheric pressure, suggesting that, in terms of order of importance, the ammonium concentration of feed-stock(x_w), the average ultra-gravity factor(β), feed-stock flux(L), and gas flux(G) had significant impact on ammonium removal rate(η) and the ammonium concentration of products(x_D). In the experiment, mass-transfer coefficient in gas phase(k_ya_e) increases with the increase of β, G/L, and L. The ammonium concentration of products decreases with the increase of β, G/L and the increase of L. The ammonium concentration of products would be as low as ~0.10% and the ammonia removal rate would be 63.21% when skim temperature was 25 °C, x_w0.28%, β 133.2, and G/L 15.0 m^3·L^(-1). Experiment results indicated that the proposed technology for removing ammonium from skim on a rotating packed bed would be a new process-intensified technique compared with traditional aeration process and centrifugal atomization method.

关键词： Skim Ammonia removal Ultra-gravity technology Air stripping

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Seasonal　Variations　in　the　Vertical　Structure　of　Water　Vapor　Optical　Depth　in　the　Lower　Troposphere　over　a　tropical　station

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Advances in Atmospheric Sciences 1997年第1期14卷 104-111页

作者： P. Ernest Raj and P.C.S. Devara Indian Institute of tropical Meteorology, Pune-411008, India Indian Institute of tropical Meteorology Pune India

Spatio-temporal variations of water vapor optical depth in the lower troposphere (450-3850 m) over Pune (18°32′N, 73°51′E, 559 m Above Mean Sea Level), India have been studied over a period of five years. The mean vertical structure showed that the moisture content is greatest at the lowest level and decreases with increasing altitude, except in the south-west monsoon season (June to September) where an increase upto 950 m has been found. Optical depths are maximum in the monsoon season. The increase from pre-monsoon (March-May) to monsoon season in moisture content on an average is by about 58% in the above altitude range. The temporal variations in surface Relative Humidity and optical depth at 450 m show positive correlation. The amplitude of seasonal oscillation is the largest at 1465 m altitude. The time-height cross-sections of water vapor optical depths in the lower troposphere showed a contrast between years of good and bad monsoon.

关键词： Optical depth Precipitable water

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Differential effects of internal tagging depending on depth treatment in Atlantic salmon:a cautionary tale for aquatic animal tag use

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Current Zoology 2019年第6期65卷 665-673页

作者： Daniel W.WRIGHT Lars H.STIEN Tim DEMPSTER Frode oPPEDAL Institute of Marine research Matre Research StationMatredalNorway Sustainable Aquaculture Laboratory-Temperate and tropical School of BioSciencesUniversity of MelbourneParkvilleAustralia

Electronic tags are widespread tools for studying aquatic animal behavior;however,tags risk behavioral manipulation and negative welfare *** an experiment to test behavioral differences of Atlantic salmon Sal mo salar in different aquaculture cage types,including ones expected to elicit deeper swimming behavior,we found negative tagging effects depending on whether cages were *** the experiment,data storage tags implanted in Atlantic salmon tracked their depth behavior and survival in unmodified sea-cages and depth-modified seacages that forced fish below or into a narrow seawater-or freshwater-filled snorkel tube from a 4 m net roof to the *** tagged individuals survived in unmodified cages;however,survival was reduced to 62%in depth-modified *** in depth-modified cages spent considerably less time above 4 m than those in unmodified cages,and dying individuals in depth-modified cages tended to position in progressively shallower *** maximum depth that fish in our study could attain neutral buoyancy was estimated at 22 m in *** calculated that the added tag weight in water reduced this to 8 m,and subtracting the tag volume from the peritoneal cavity where the swim bladder reinflates reduced this further to 4 *** conclude that the internal tag weight and volume affected buoyancy regulation as well as the survival and behavior of tagged *** tagging studies on aquatic animals should carefully consider the buoyancy-related consequences of internal tags with excess weight in water,and the inclusion of data from dying tagged animals when estimating normal depth behaviors.

关键词： Atlantic salmon physostome Salmo salar swim bladder swimming depth tagging effects

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Dynamics of nonstructural carbohydrates in seagrass Thalassia hemprichii and its response to shading

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Acta Oceanologica Sinica 2013年第8期32卷 61-67页

作者： JIANG Zhijian HUANG Xiaoping ZHANG Jingping Key Laboratory of tropical Marine Bio-resources and Ecology South China Sea Institute of Oceanology Chinese Academy of Sciences tropical Marine Biological research station in Hainan Chinese Academy of Sciences

A field survey was performed to examine nonstructural carbohydrate （NSC） dynamics in seagrass Thalassia hemprichii at the Xincun Bay in southern China. An indoor experiment to investigate the response of NSC in T. hemprichiito shade was conducted. Belowground tissue of T. hemprichiiwas the dominant site of NSC reserves, and soluble sugar was the primary storage compound. The starch content of belowground tissue was lower in high intertidal areas than in low intertidal areas, indicating that the longer air exposure in high intertidal areas resulted in less NSC synthesis and less accumulation of NSC in T. hemprichii. The lowest level of soluble sugar and its proportion to NSC in belowground tissue were observed near the cage culture area, where the nutrient concentration in water and sediment was the highest; while the highest level of that was observed near the coastal shrimp farm, where salinity was the lowest. Soluble sugar in belowground tis- sue showed the following trend： summer〉spring〉winter〉autumn. This corresponded to seasonal changes in the intensity of light. Leaf sugar accumulated during the autumn-winter period, providing a carbon and energy source for flower bud formation and seed germination. Short-term shading decreased NSC accumu- lation. Collectively, these results suggest that nutrient enrichment, freshwater discharge and exposure to air affect NSC dynamics in T. hemprichii. Light intensity, flower bud formation, and seed germination were all found to induce seasonal variations in NSC in T. hemprichii.

关键词： Thalassia hemprichii nonstructural carbohydrates Xincun Bay dynamics shade

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Efficient regeneration system applicable to five Musa cultivars

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Frontiers of Agricultural Science and Engineering 2016年第4期3卷 330-334页

作者： Juhua LIU Peiguang SUN Jing ZHANG Jiashui WANG Jianbin ZHANG Jingyi WANG Caihong JIA Pengzhao GAO Biyu XU Zhiqiang JIN Key Laboratory of tropical Crop Biotechnology Ministry of Agriculture/Institute of Tropical Bioscience and BiotechnologyChinese Academy of Tropical Agricultural Sciences Haikou Experimental station Chinese Academy of Tropical Agricultural Sciences

Banana(Musa spp.) is an important staple food, economic crop, and nutritional fruit *** is seriously hampered by the long generation time, polyploidy, and sterility of most *** of an efficient regeneration and transformation system for banana is critical for their genetic improvement. An efficient and reproducible transformation system for banana using direct organogenesis was developed. Media containing benzylaminopurine(BA)combined with one of four other growth regulators was evaluated for the regeneration efficiency of five Musa cultivars and the ability to induce/support development of new banana shoots. The result indicated that the greatest number of shoots per explant for all five Musa cultivars was obtained using MS medium supplemented with8.9 mmol$L–1BA and 9.1 mmol$L–1thidiazuron(TDZ).In 240–270 d, one immature male flower could regenerate between 380 and 456, 310–372, 200–240, 130–156, and100–130 well-developed shoots for Gongjiao, Red banana, Rose banana, Baxi, and Xinglongnaijiao, respectively. Such a system will facilitate molecular breeding and functional genomics of banana.

关键词： banana(Musa spp) system regeneration

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Genome-wide identification and expression analysis of the β-amylase genes strongly associated with fruit development,ripening, and abiotic stress response in two banana cultivars

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Frontiers of Agricultural Science and Engineering 2016年第4期3卷 346-356页

作者： Hongxia MIAO Peiguang SUN Yulu MIAO Juhua LIU Jianbin ZHANG Caihong JIA Jingyi WANG Zhuo WANG Zhiqiang JIN Biyu XU Key Laboratory of tropical Crop Biotechnology Ministry of Agriculture Institute of Tropical Bioscience and BiotechnologyChinese Academy of Tropical Agricultural Sciences Key Laboratory of Genetic Improvement of Bananas Hainan Province Haikou Experimental StationChinese Academy of Tropical Agricultural Sciences Department of agriculture Hainan University

β-amylase(BAM) is an important enzyme involved in conversion of starch to maltose in multiple biological processes in plants. However, there is currently insufficient information on the BAM gene family in the important fruit crop banana. This study identified 16 BAM genes in the banana genome. Phylogenetic analysis showed that Ma BAMs were classified into four subfamilies. Most Ma BAMs in each subfamily shared similar gene structures. Conserved motif analysis showed that all identified Ma BAM proteins had the typical glyco hydro14 domains. Comprehensive transcriptomic analysis of two banana genotypes revealed the expression patterns of Ma BAMs in different tissues, at various stages of fruit development and ripening, and in responses to abiotic stresses. Most Ma BAMs showed strong transcript accumulation changes during fruit development and late-stage ripening. Some Ma BAMs showed significant changes under cold, salt, and osmotic stresses. This finding indicated that Ma BAMs might be involved in regulating fruit development, ripening, and responses to abiotic stress. Analysis of five hormone-related and seven stressrelevant elements in the promoters of Ma BAMs further revealed that BAMs participated in various biological processes. This systemic analysis provides new insights into the transcriptional characteristics of the BAM genes in banana and may serve as a basis for further functional studies of such genes.

关键词： β-amylase banana genome-wide identification fruit development abiotic stress

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